The contribution of the cervix to sexual response: an online survey study.

BACKGROUND: The role of the cervix in sexual response has been poorly studied, despite previous research indicating that some women experience pleasurable sexual sensations from cervical stimulation; given previous reports of sexual issues after cervix electrocautery, it is possible that cervical injury may compromise the role of the cervix in sexual functioning. AIM: The aims of this study were to examine locations of pleasurable sexual sensations, to identify sexual communication barriers, and to investigate if cervical procedures are associated with negative impacts on sexual function. METHODS: Women with (n = 72) and without (n = 235) a history of a gynecological procedure completed an online survey assessing demographics, medical history, sexual function (including locations of sexual pleasure and pain on diagrams), and barriers. The procedure group was divided into subgroups of those who had experienced a cervical (n = 47) or noncervical (n = 25) procedure. Chi-square analyses and t tests were conducted. OUTCOMES: Outcomes included locations and ratings of pleasurable and painful sexual stimulation, as well as sexual function. RESULTS: Over 16% of participants reported experiencing some pleasurable sexual sensations from the cervix. The gynecological procedure group (n = 72) reported significantly higher pain in the vagina and lower rates of pleasure in their external genitals, vagina, deep vagina, anterior and posterior vaginal walls, and clitoris vs the non-gynecological procedure (n = 235) group. The gynecological procedure group and the cervical procedure subgroup (n = 47) reported significant decreases in desire, arousal, and lubrication and increased avoidance of sexual activity due to vaginal dryness. The gynecological procedure group reported significant pain with vaginal stimulation, whereas the cervical subgroup identified significant pain with cervical and clitoral stimulation. CLINICAL IMPLICATIONS: Cervical stimulation elicits some pleasurable sexual sensations for many women, and gynecological procedures that affect the cervix are associated with pain and sexual issues; thus, health care providers should counsel patients about the possibility of related sexual concerns. STRENGTHS AND LIMITATIONS: This study is the first to examine locations of pleasure and pain and experiences of sexual pleasure and function in participants who underwent a gynecological procedure. A hybrid measure was used to assess sexual issues, including symptoms of dysfunction. CONCLUSION: Results indicate an association between cervical procedures and sexual issues, supporting the need to inform patients of this possibility following cervical procedures.

The prostate in women: an updated histological and immunohistochemical profile of the female periurethral glands and their relationship to an implanted midurethral sling.

BACKGROUND: There is evidence of glandular tissue in the region of the anterior vaginal wall-female periurethral tissue (AVW-FPT) that has similar morphology and immunohistochemistry to the prostate in men. Surgical injury to this tissue has been suggested as a potential cause of sexual dysfunction following midurethral sling (MUS) procedures. However, the anatomy and embryology of these glands have not been fully resolved. This has led to difficulties in classifying this tissue as a prostate and defining its clinical significance related to MUS procedures. AIM: To describe the histological and immunohistochemical characteristics of the female periurethral glands using markers of prostate tissue and innervation and to examine their anatomical relationships to an implanted MUS. METHODS: Using gross and fine dissection, the AVW-FPT was dissected from 9 cadavers. Prior to dissection, 2 cadavers underwent simulation of the MUS procedure by a urogynecologist. Samples were paraffin embedded and serially sectioned. Immunohistochemistry was performed using markers of prostate tissue and innervation. OUTCOMES: Immunohistochemical localization of markers for prostatic tissue and innervation of the glandular tissue of the AVW-FPT, including the region of MUS implantation. RESULTS: Female periurethral glands were immunoreactive for markers of male prostatic tissue, including prostate-specific antigen, androgen receptor, HOXB13, and NKX3.1. Markers of innervation (protein gene product 9.5, choline acetyl transferase, and vasoactive intestinal polypeptide) also localized to certain regions of the glandular tissue and associated blood supply. Surgical simulation of the MUS procedure demonstrated that some periurethral glands are located in close proximity to an implanted sling. CLINICAL TRANSLATION: The AVW-FPT contains glandular tissue in the surgical field of MUS implantation. Iatrogenic damage to the female periurethral glands and the associated innervation during surgery could explain the negative impacts on sexual dysfunction reported following MUS procedures. STRENGTHS AND LIMITATIONS: This is the first study to characterize the female periurethral glands using markers of prostatic tissue in concert with markers of general and autonomic innervation and characterize their anatomical relationships within the surgical field of MUS implantation. The small sample size is a limitation of this study. CONCLUSION: We provide further evidence that the AVW-FPT contains innervated glands that are phenotypically similar to the male prostate and may share a common embryonic origin. The microscopic and immunohistochemical features of the periurethral glands may be indicative of their functional capacity in sexual responses. The location of these glands in the surgical field of MUS procedures underscores the clinical significance of this tissue.

Patient and provider perspectives on LEEP/LLETZ treatment and outcomes: an interview study.

BACKGROUND: The loop electrosurgical excision procedure (LEEP) and large loop excision of the transformation zone (LLETZ) effectively treat cervical dysplasia, though some women have reported negative outcomes postoperatively (e.g., sexual dysfunction, psychosexual sequalae). There is insufficient understanding of patient experiences with these symptoms and perspectives from the providers who perform LEEP/LLETZ. AIM: To characterize the perceptions and experiences of LEEP/LLETZ treatment from providers and patients, including whether there is a characteristic symptom profile of women who report negative outcomes. METHODS: Patients who had LEEP/LLETZ treatment and reported negative outcomes and providers who perform LEEP/LLETZ completed semistructured interviews about their perceptions and experiences, which were coded through thematic analysis (NVivo 12; QSR International). Patients also completed an online survey assessing demographics, medical history, and sexual function. OUTCOMES: Outcomes included perspectives generated from patient and provider interviews regarding LEEP/LLETZ procedural outcomes, including symptoms and experiences related to sexual functioning. RESULTS: Perspectives and experiences gathered from patient and provider interviews revealed misaligned narratives surrounding LEEP/LLETZ outcomes and treatment. We identified 4 overarching themes encapsulating provider and patient responses: Expectations for Preoperative Consultation; Procedure Experiences; Attitudes; and Resources. Patients reported a unique symptom profile and negative outcome experiences, namely surrounding domains of sexual functioning: decreased physical sensations, orgasm response, and vaginal discharge, as well as loss of arousal, interest, and desire. Patients described changes to overall quality of life, with impacts to interpersonal relationships. Patients discussed preferring open-ended and directed questions to comprehensively elucidate negative outcomes. Provider narratives outlined the current process of care, emphasizing limited experiences with adverse outcomes (e.g., sexual issues) and the use of open-ended questions during counseling. Providers described an evolving intention to create comfortable clinical spaces. Regarding pre- and postoperative resources, patients described seeking support from online patient groups, and providers disclosed limitations to providing resources. CLINICAL IMPLICATIONS: Evidence of discordance between patient and provider perspectives of LEEP/LLETZ reveals a need to reassess clinical practices surrounding this procedure at the level of discussions regarding informed consent, sexual function, and available resources. STRENGTHS AND LIMITATIONS: This study is the first to examine patient and provider perspectives on LEEP/LLETZ treatment. Only patients who self-report negative outcomes were recruited, to elicit narratives from this specific subpopulation. CONCLUSION: Results indicate a characteristic symptom profile of women who undergo LEEP/LLETZ and report negative outcomes and that the perceptions of patients and providers differ regarding several aspects of the treatment experience, supporting the need for directed open conversation and comprehensive pre- and postoperative sexual counseling.

Characterizing the innervation of the vulvar vestibule and the immunohistochemical features of neuroproliferative vestibulodynia.

BACKGROUND: Provoked vestibulodynia (PVD) is a chronic pain condition characterized by allodynia localized to the vulvar vestibule. The finding of increased densities of nerve fibers in the vestibular mucosa of patients with PVD has led to the identification of a neuroproliferative subtype. The etiology of PVD, including neuroproliferative vestibulodynia (NPV), is not fully understood. The gross and microscopic innervation of the vulvar vestibule remains incompletely described, despite the preliminary data supporting the role of peripheral innervation in PVD. AIM: To characterize the gross anatomic and microscopic innervation of the vulvar vestibule through cadaveric dissection and immunohistochemistry. METHODS: The pudendal nerve and inferior hypogastric plexus (IHP) were dissected using 6 cadaveric donors. Histology and immunohistochemistry were used to confirm patterns of innervation identified gross anatomically. Immunohistochemistry was performed on vestibulectomy specimens obtained from 6 patients diagnosed with NPV and compared with cadaveric vestibular tissues. OUTCOMES: Outcomes included (1) dissection of pelvic innervation and (2) immunohistochemical localization of markers for the following: general innervation protein gene product 9.5 (PGP9.5), sensory innervation (calcitonin gene-related peptide), autonomic innervation (vasoactive intestinal polypeptide, tyrosine hydroxylase), neuroproliferation (nerve growth factor [NGF]), and immune activation (C-kit). RESULTS: Perineal (pudendal) nerve branches were traced to the external wall of the vulvar vestibule. Some anatomic heterogeneity was observed in perineal nerve-branching patterns. Fibers from the IHP were identified in close proximity to the vulvar vestibule. Autonomic and sensory nerve fibers were identified in both patient and cadaveric vulvar vestibule samples. Patient samples were characterized by the proliferation of PGP9.5-positive nerve fibers and C-kit-positive mast cells, which were in proximity to neve bundles and showed coexpression with putative NGF-positive cells. NGF expression was localized to a subset of nerves, including those that demonstrated co-expression of sensory and autonomic nerve markers. Increased densities of autonomic fibers positive for vasoactive intestinal polypeptide and tyrosine hydroxylase were observed in 1 patient sample. CLINICAL TRANSLATION: Heterogeneity in gross and microscopic patterns of innervation could explain variability in clinical response to treatment and should be used to inform future therapeutic interventions. STRENGTHS AND LIMITATIONS: This study used a combination of approaches to elucidate the innervation of the vulvar vestibule, including in NPV. The small sample size is a limitation. CONCLUSION: The vulvar vestibule contains both sensory and autonomic innervation, which may originate from the pudendal nerve and IHP. Our results support the existence of a neuroproliferative subtype that is characterized by the proliferation of sensory and autonomic nerve fibers and neuroimmune interactions.

Cardiometabolic Diseases and Female Sexual Dysfunction: Animal Studies.

BACKGROUND: The association between erectile dysfunction and cardiometabolic disease is well characterized; men are often diagnosed with cardiovascular disease 2-5 years following the incidence of erectile dysfunction. There is evidence that this relationship may also exist for cardiometabolic diseases and female sexual dysfunction (FSD) - particularly sexual arousal disorders. AIM: To provide a summary of the preclinical literature related to the evidence of FSD in animal models of cardiometabolic diseases and indicate where further research is needed. METHODS: A detailed Medline search of peer-reviewed publications was performed on the associations between animal models of cardiometabolic diseases, FSD and underlying mechanisms. OUTCOMES: A summary of the preclinical evidence of FSD in animal models of cardiometabolic diseases. RESULTS: Common methods for assessing female sexual arousal and physiology in animal models include: 1) behavioral assessments (apomorphine-induced genital vasocongestive arousal; hormone-dependent lordosis), 2) nerve-mediated vaginal and clitoral blood flow, 3) pudendal artery, vaginal and clitoral smooth muscle physiology (vasoreactivity and molecular biology), 4) morphology of genital tissues. Twenty-eight studies examined female animal models of atherosclerosis, hypertension, diabetes (type 1 and 2) and obesity. They showed functional alterations, including decreased lordosis, lubrication, or vaginal and clitoral blood flow, and structural impairments, such as increased clitoral and vaginal fibrosis. Several possible mechanisms have been described including increased TGF-ß, renin angiotensin system and endothelin/rho-kinase signaling, increased reactive oxygen species, and decreased nitric oxide/cGMP signaling. CLINICAL TRANSLATION: In line with existing clinical studies, preclinical evidence supports that cardiometabolic diseases alter female genital tissue's function and structure leading to impaired sexual arousal. STRENGTHS AND LIMITATIONS: This masterclass paper gives an overview of the preclinical research assessing FSD in cardiometabolic disease. Limitations include the small number of studies that have assessed sexual function and arousal in female cardiometabolic animal models. CONCLUSION: Preclinical evidence exists showing cardiometabolic diseases alter the structure and function of female genital tissues. However, similar to clinical studies, there are few studies to draw from, particularly in models of type 2 diabetes, obesity and metabolic syndrome. More studies are required using optimized animal models and methodology to confirm the mechanisms underlying cardiometabolic disease-induced FSD. Angulo J, Hannan JL. Cardiometabolic Diseases and Female Sexual Dysfunction: Animal Studies. J Sex Med 2022;19:408-420.

Cocultured Schwann Cells Rescue Irradiated Pelvic Neuron Outgrowth and Increase Survival.

BACKGROUND: Prostatic radiation therapy (RT) leads to erectile dysfunction by damaging peri-prostatic pro-erectile nerves of the pelvic ganglion. Schwann cells (SC) facilitate neuronal repair after mechanical injury, however, their role in repair of pelvic neurons post-radiation hasn't been explored. AIM: To determine if SCs cocultured with primary pelvic neurons can rescue neuronal survival and growth after ex vivo RT. METHODS: Major pelvic ganglia (MPG) were collected from adult male Sprague-Dawley rats (n = 12) to isolate SCs. SCs received RT (0 or 8 Gy), were plated on coated coverslips and grown to confluence before the addition of neurons. Additional MPGs were irradiated (0 or 8 Gy) and digested to isolate pelvic neurons. Dissociated neurons were plated alone or atop SC-coated coverslips to create 6 experimental groups (n = 3/grp): (i) Control (CON) MPG, (ii) RT MPG, (iii) CON SC + CON MPG, (iv) CONSC + RT MPG, (v) RT SC + CON MPG, and (iv) RT SC + RT MPG. After 72 hours, coverslips were fixed and stained for beta-tubulin (neuron marker), S100 (SC marker), neuronal nitric oxide synthase (nitrergic marker), tyrosine hydroxylase (sympathetic marker), and terminal deoxynucleotidyl transferase dUTP nick-end labeling. OUTCOMES: We measured neurite length, branching, specific neuron populations and apoptosis. RESULTS: Ex vivo RT decreased MPG neuron length, increased apoptosis and decreased nitrergic neurons in monoculture. Compared to all other groups, CON SC + RT MPG cocultures demonstrated increased neurite outgrowth (P < .001). Neurite branching was decreased in the RT MPG + RT SC coculture, but unchanged in other cocultures. Groups containing RT MPG neurons exhibited increased apoptosis, but coculture with CON SC reduced the degree of RT-induced apoptosis (P < .01). The number of tyrosine hydroxylase positive neurons was unchanged while nitrergic neurons were significantly lower in RT neurons and coculture with CON SCs was unable to prevent nitrergic loss. CLINICAL TRANSLATION: These findings suggest that SCs may be an important target in prostate cancer patients with radiation-induced pelvic neuropathy to promote MPG neuron survival and neuronal repair after RT. STRENGTHS AND LIMITATIONS: This is the first study to characterize the ex vivo ability of SCs to rescue pelvic nerve growth and survival. The study is limited by little supporting mechanistic molecular data and the need to confirm the ability of healthy SCs to promote pelvic neuron survival and repair following prostatic RT in vivo. CONCLUSION: Unirradiated SCs partially mitigated RT-induced MPG apoptosis but did not affect the loss of nitrergic neuron populations suggesting that SCs promote irradiated MPG neuron survival and facilitate intrinsic repair functions. Randolph JT, Pak ES, McMains JC, et al. Cocultured Schwann Cells Rescue Irradiated Pelvic Neuron Outgrowth and Increase Survival. J Sex Med 2022;19:1333-1342.

Immunohistochemical Investigation of Autonomic and Sensory Innervation of Anterior Vaginal Wall Female Periurethral Tissue: A Study of the Surgical Field of Mid-Urethral Sling Surgery Using Cadaveric Simulation.

BACKGROUND: Female sexual dysfunction, including female orgasm disorder, has been reported following mid-urethral sling (MUS) surgery to treat bothersome stress urinary incontinence. Anterior vaginal wall-female periurethral tissue (AVW-FPT) likely contains autonomic and sensory innervation involved in the female sexual response, and injury to these nerves may result from MUS implantation. AIM: To characterize, using fresh cadaveric tissue, autonomic and sensory nerves in AVW- FPT using immunohistochemistry (IHC), and to assess their proximity to an implanted MUS. METHODS: AVW-FPT was excised following careful dissection from four fresh cadavers. Prior to dissection, one cadaver underwent simulation of the MUS procedure by a urogynegologist, using a fascial sling. All samples were paraffin embedded, sectioned, and stained with hematoxylin. Serial sectioning and IHC were performed to identify nerves. IHC markers were used to characterize the sensory and autonomic innervation. OUTCOMES: IHC localization of autonomic and sensory nerve markers consistent with neural tissue within the region of MUS implantation. RESULTS: IHC of AVW-FPT using protein gene product 9.5 (PGP9.5), a general nerve stain, revealed innervation throughout the region targeted by the MUS implantation. More specifically, immunoreactivity for both autonomic (tyrosine hydroxylase, TH) and sensory (Nav1.8 and S100ß) nerves were found in close proximity (<1 mm) to the implanted MUS. In addition, a subset of S100ß positive nerves also showed immunoreactivity for calcitonin gene-related peptide (CGRP). Combining the IHC findings with the surgical simulation of the MUS implantation revealed the potential for damage to both autonomic and sensory nerves as a direct result of the MUS procedure. CLINICAL TRANSLATION: The identified autonomic and sensory nerves of the AVW-FPT may contribute to the female sexual response, and yet are potentially negatively impacted by MUS procedures. Given that surgeries performed on male genital tissue, including the prostate, may cause sexual dysfunction secondary to nerve damage, and that urologists routinely provide informed consent regarding this possibility, urogynaecologists are encouraged to obtain appropriate informed consent from prospective patients undergoing the MUS procedure. STRENGTHS & LIMITATIONS: This is the first study to characterize the sensory and autonomic innervation within the surgical field of MUS implantation and demonstrate its relationship to an implanted MUS. The small sample size is a limitation of this study. CONCLUSION: The present study provides evidence of potential injury to autonomic and sensory innervation of AVW-FPT as a consequence of MUS implantation, which may help explain the underlying mechanisms involved in the reported post-operative female sexual dysfunction in some women. Giovannetti O, Tomalty D, Gaudet D, et al. Immunohistochemical Investigation of Autonomic and Sensory Innervation of Anterior Vaginal Wall Female Periurethral Tissue: A Study of the Surgical Field of Mid-Urethral Sling Surgery Using Cadaveric Simulation. J Sex Med 2021;18:1168-1180.

Increased Level of Tumor Necrosis Factor-Alpha (TNF-α) Leads to Downregulation of Nitrergic Neurons Following Bilateral Cavernous Nerve Injury and Modulates Penile Smooth Tone.

BACKGROUND: Erectile dysfunction (ED) after injury to peripheral cavernous nerve (CN) is partly a result of inflammation in pelvic ganglia, suggesting that ED may be prevented by inhibiting neuroinflammation. AIM: The aim of this study is to examine temporal changes of TNF-α, after bilateral CN injury (BCNI), to evaluate effect of exogenous TNF-α on neurite outgrowth from major pelvic ganglion (MPG), and to investigate effect of TNF-α signal inhibition to evaluate effects of TNF-α on penile tone with TNF-α receptor knockout mice (TNFRKO). METHODS: Seventy Sprague-Dawley rats were randomized to undergo BCNI or sham surgery. Sham rats' MPGs were harvested after 48 hours, whereas BCNI groups' MPGs were at 6, 12, 24, 48 hours, 7, or 14 days after surgery. qPCR was used to evaluate gene expression of markers for neuroinflammation in MPGs. Western blot was performed to evaluate TNF-α protein amount in MPGs. MPGs were harvested from healthy rats and cultured in Matrigel with TNF-α. Neurite outgrowth from MPGs was measured after 3 days, and TH and nNOS immunofluorescence was assessed. Wild type (WT) and TNFRKO mice were used to examine effect of TNF-α inhibition on smooth muscle function after BCNI. MPGs were harvested 48 hours after sham or BCNI surgery to evaluate gene expression of nNOS and TH. OUTCOMES: Gene expression of TNF-α signaling pathway, Schwann cell and macrophage markers, protein expression of TNF-α in MPGs, and penile smooth muscle function to electrical field stimulation (EFS) were evaluated. RESULTS: BCNI increased gene and protein expression of TNF-α in MPGs. Exogenous TNF-α inhibited MPG neurite outgrowth. MPGs cultured with TNF-α had decreased gene expression of nNOS (P < .05). MPGs cultured with TNF-α had shorter nNOS+ neurites than TH+ neurites (P < .01). Gene expression of nNOS was enhanced in TNFRKO mice compared to WT mice (P < .01). WT mice showed enhanced smooth muscle contraction of penises of WT mice was enhanced to EFS, compared to TNFKO (P < .01). Penile smooth-muscle relaxation to EFS was greater in TNFKO mice compared to WT (P < .01). CLINICAL TRANSLATION: TNF-α inhibition may prevent ED after prostatectomy. STRENGTH/LIMITATIONS: TNF-α inhibition might prevent loss of nitrergic nerve apoptosis after BCNI and preserve corporal smooth muscle function but further investigation is required to evaluate protein expression of nNOS in MPGs of TNFKO mice. CONCLUSIONS: TNF-α inhibited neurite outgrowth from MPGs by downregulating gene expression of nNOS and TNFRKO mice showed enhanced gene expression of nNOS and enhanced penile smooth-muscle relaxation. Matsui H, Sopko NA, Campbell JD, et al. Increased Level of Tumor Necrosis Factor-Alpha (TNF-α) Leads to Downregulation of Nitrergic Neurons Following Bilateral Cavernous Nerve Injury and Modulates Penile Smooth Tone. J Sex Med 2021;18:1181-1190.

Dysfunctional voiding behavior and impaired muscle contractility in a rat model of detrusor underactivity.

AIMS: Detrusor underactivity (DU) is an understudied health concern with inadequate clinical management. The pathophysiology of DU is unclear, and current therapies fail to improve symptoms. The current studies characterized voiding function and contractility of bladder and urethral tissues in a novel rat model of DU. METHODS: Female obese prone (OP) and obese resistant (OR) rats were fed a 60 kcal% fat diet at 8 weeks old. A subset of rats (n = 4/strain) underwent uroflowmetry biweekly for 18 weeks in metabolic cages. At 40-56 weeks old, rats (n = 9-10/strain) underwent instrumented cystometry under urethane anesthesia. Following cystometry, bladder and urethral tissues (n = 8-9/strain) were harvested for in vitro assessments of contractility in response to carbachol, electric field stimulation, atropine, alpha, beta-methylene ATP, and caffeine. RESULTS: OP rats exhibited increased urinary frequency (p = 0.0031), decreased voided volume (p = 0.0093), and urine flow rate (p = 0.0064) compared to OR rats during uroflowmetry. Bethanechol (10 mg/kg) did not alter uroflowmetry parameters. During cystometry, OP rats exhibited decreased bladder emptying efficiency (p < 0.0001), decreased pressure to generate a void (p < 0.0001), and increased EUS activity during filling (p = 0.0011). Bladder contractility was decreased in OP rats when exposed to carbachol (p < 0.0003) and ATP (p = 0.0004), whereas middle urethral contractility was increased when exposed to carbachol (p = 0.0014), EFS (p = 0.0289), and caffeine (p = 0.0031). CONCLUSION: Impaired cholinergic and purinergic signaling in the bladder may contribute to poor voiding function in OP rats. In addition, increased urethral activity may engage a guarding reflex to augment continence and exacerbate incomplete emptying.

Impact of prostatic radiation therapy on bladder contractility and innervation.

AIMS: To determine the effect of prostatic radiation therapy (RT) on bladder contractility and morphology, and axon, or neuron profiles within the detrusor and major pelvic ganglia (MPG) in male rats. METHODS: Male Sprague-Dawley rats (8 weeks) received a single dose of prostatic RT (0 or 22 Gy). Bladders and MPG were collected 2- and 10-weeks post-RT. Detrusor contractile responses to carbachol and electrical field stimulation (EFS) were measured. Bladders were stained with Masson's trichrome, and antibodies for nonspecific neuronal marker, cholinergic nerve marker choline acetyltransferase (ChAT), and alpha-smooth muscle actin. MPG gene expression was assessed by quantitative polymerase chain reaction for ubiquitin carboxy-terminal hydrolase L1 (Uchl1) and Chat. RESULTS: At 2 weeks post-RT, bladder smooth muscle, detrusor cholinergic axon profiles, and MPG Chat gene expression were increased (p < .05), while carbachol and EFS-mediated contractions were decreased (p < .05). In contrast, at 10 weeks post-RT, nerve-mediated contractions were increased compared with control (p < .05), while bladder smooth muscle, detrusor cholinergic axon profiles, MPG Chat expression, and carbachol contractions had normalized. At both 2- and 10-weeks post-RT, there was no change in detrusor nonspecific axon profiles and MPG Uchl1 expression. CONCLUSION: In a rat model, RT of the prostate and MPG was associated with early changes in MPG Chat gene expression, and bladder cholinergic axon profiles and smooth muscle content which resolved over time. After RT recovery, bladder contractility decreased early and increased by 10 weeks. Long-term changes to the MPG and increased bladder cholinergic axons may contribute to RT-induced bladder dysfunction in prostate cancer survivors.

Ex Vivo Radiation Leads to Opposing Neurite Growth in Whole Ganglia vs Dissociated Cultured Pelvic Neurons.

BACKGROUND: Prostatic radiation therapy (RT) often causes erectile dysfunction (ED) and the mechanisms governing RT-induced ED are unclear with a lack of therapeutic strategies. AIM: To determine the effects of ex vivo RT on major pelvic ganglion (MPG) neuron survival, and neurite growth in whole vs dissociated culture. METHODS: MPGs were removed and irradiated (0 or 8 Gy) from male Sprague Dawley rats. For dissociated culture, MPG neurons were digested in collagenase/dispase and cultured on coverslips. Immunofluorescent staining for beta-tubulin III (TUBB3; neuron marker), neuronal nitric oxide synthase (nNOS; nitrergic marker), tyrosine hydroxylase (TH; sympathetic marker), and terminal deoxynucleotidyl transferase dUTP nick end labeling assessed neurite length, branching, autonomic neuron density, and apoptosis. For whole organ culture, MPGs were grown in Matrigel. Gene expression of apoptotic markers (caspase 1, 3), TUBB3, nNOS, TH, and Schwann cells (Sox10, Krox20, glial fibrillary acid protein) was measured in whole organ cultured MPGs by quantitative polymerase chain reaction. OUTCOMES: After 72 hours, neurite length, branching, autonomic neuron density, and apoptosis were assessed, and gene expression was measured. RESULTS: RT increased apoptosis in dissociated neurons measured by terminal deoxynucleotidyl transferase dUTP nick end labeling (P < .001) and whole MPG culture via upregulation of caspase 3 gene expression (P < .05). Nitrergic neurons were markedly decreased in irradiated dissociated culture (P < .05), while nNOS gene expression was upregulated in irradiated whole organ culture (P < .05). The proportion of dissociated sympathetic neurons and whole organ TH gene expression remained unchanged after RT. Interestingly, RT dissociated neurites were 22% shorter than controls, while RT whole organ neurites were 15% longer than controls (P < .01). MPG Schwann cells markers (Sox10, Krox20) were elevated after RT in whole organ culture. CLINICAL TRANSLATION: Prostatic RT leads to increased neuronal cell death and less erectogenic nitrergic neurons contributing to ED. STRENGTHS & LIMITATIONS: The advantages of dissociated neuron culture include distinct neurites which are easily measured for apoptosis, length/branching, and specific neuron types. In contrast, whole MPG culture is advantageous as it contains all the supporting cells present in vivo. CONCLUSION: The 2 different culture methods demonstrated opposing neurite growth after RT indicating the importance of supporting cell network to promote pelvic neuron neuritogenesis and survival following RT. Randolph JT, Pak ES, Koontz BF, et al. Ex Vivo Radiation Leads to Opposing Neurite Growth in Whole Ganglia vs Dissociated Cultured Pelvic Neurons. J Sex Med 2020;17:1423-1433.

A free-choice high-fat, high-sucrose diet induces hyperphagia, obesity, and cardiovascular dysfunction in female cycling and pregnant rats.

The main objective of these studies was to characterize metabolic, body composition, and cardiovascular responses to a free-choice high-fat, high-sucrose diet in female cycling and pregnant rats. In the nonpregnant state, female Sprague-Dawley rats offered a 3-wk free-choice high-fat, high-sucrose diet had greater energy intake, adiposity, serum leptin, and triglyceride concentrations compared with rats fed with standard chow and developed glucose intolerance. In addition, choice-diet-fed rats had larger cardiac ventricular weights, smaller kidney and pancreas weights, and higher blood pressure than chow-fed rats, but they did not exhibit resistance artery endothelial dysfunction. When the free-choice diet continued throughout pregnancy, rats remained hyperphagic, hyperleptinemic, and obese. Choice pregnant rats exhibited uterine artery endothelial dysfunction and had smaller fetuses compared with chow pregnant rats. Pregnancy normalized mean arterial blood pressure and pancreas weights in choice rats. These studies are the first to provide a comprehensive evaluation of free-choice high-fat, high-sucrose diet on metabolic and cardiovascular functions in female rats, extending the previous studies in males to female cycling and pregnant rodents. Free-choice diet may provide a new model of preconceptual maternal obesity to study the role of increased energy intake, individual food components, and preexisting maternal obesity on maternal and offspring physiological responses during pregnancy and after birth.

Prostate-Confined Radiation Decreased Pelvic Ganglia Neuronal Survival and Outgrowth.

BACKGROUND: Erectile dysfunction (ED) is common following radiation therapy (RT) for prostate cancer. Although the cause of RT-induced ED is unknown, damage to both the neuronal and vascular components supporting erections are often implicated. AIM: To determine the effects of prostatic RT on erections, penile vascular physiology, and major pelvic ganglia (MPG) neuron growth and survival in a rat model. METHODS: Male rats underwent 0 Gy or 22 Gy single fraction of prostate-confined, conformal RT. At 2 weeks or 10 weeks post-RT (n = 10/group), cavernous nerve stimulation was performed and erections were assessed. Tissue bath experiments were performed to assess both penile artery and internal pudendal artery (IPA) function. MPGs were dissociated and neurons grown in culture for 72 hours. Immunofluorescence staining was done to quantify neuron survival (terminal deoxynucleotidyl transferase nick-end labeling), outgrowth (beta-tubulin III), type (nitric oxide synthase [nNOS] and tyrosine hydroxylase [TH]), and nerve injury markers (small GTPase Rac1 and ninjurin-1 [Ninj-1]). Whole MPG real-time quantitative polymerase chain reaction (qPCR) was performed to measure expression of genes related to nerve type, neuron injury, repair, and myelination, such as Ninj-1, Rac1, ATF3, GAP43, GFAP, SOX10, and KROX20. OUTCOMES: Intracavernosal pressure (ICP) to mean arterial pressure (MAP) ratio, smooth muscle contractility and relaxation, gene expression, neuritogenesis, and apoptosis. RESULTS: Following RT, ICP/MAP was unchanged at 2 weeks or 10 weeks. Nerve-mediated penile contraction was increased at 2 weeks, whereas adrenergic contraction was reduced at 10 weeks. Penile relaxation and IPA vasoreactivity were unchanged. Neuronal apoptosis was more than doubled both early and late post-RT. RT caused a progressive decrease in neurite branching but an early increase and then late decrease in neurite lengthening. RT reduced the numbers of nNOS-positive neurons both early and late and also decreased MPG nitrergic gene expression. TH neurons and gene expression were unchanged at 2 weeks; however, both were decreased after 10 weeks. Although most markers of gene injury and repair were unaffected early post-RT, MPG expression of Ninj1 and GFAP increased. After 10 weeks, Ninj1 and GFAP remained elevated while markers of neuron injury (ATF3), outgrowth (GAP43 and Rac1), and myelin regulation (SOX10) were decreased. CLINICAL TRANSLATION: RT-induced ED may result from damage to the ganglia controlling erections. STRENGTHS & LIMITATIONS: This study used a clinically relevant, prostate-confined model to examine neurovascular structures not accessible in human studies. Unfortunately, rats did not exhibit ED at this time point. CONCLUSION: This is the first study to demonstrate impaired health and regeneration potential of dissociated MPG neurons following RT. Neuronal injury was apparent early post-RT and persisted or increased over time but was insufficient to cause ED at the time points examined. Powers SA, Odom MR, Pak ES, et al. Prostate-Confined Radiation Decreased Pelvic Ganglia Neuronal Survival and Outgrowth. J Sex Med 2019;16:27-41.

Chronic high-fat diet decreased detrusor mitochondrial respiration and increased nerve-mediated contractions.

AIMS: To assess the impact of chronic high-fat diet (HFD) on behavioral voiding patterns, detrusor contractility, and smooth muscle mitochondrial function in male mice. MATERIALS AND METHODS: Male C57BL/6J mice (6 weeks) were fed a control or HFD for 20 weeks. Bladder function was assessed by void spot assays. Bladders were collected and detrusor contractility to carbachol (10-9 -10-5 M), and electrical field stimulation (EFS, 0.5-32 Hz) in the presence and absence of atropine was measured. Homogenized detrusor samples were placed in oxygraphs to assess the rate of oxygen consumption of the mitochondria within the detrusor in the presence of different substrates. Mitochondrial hydrogen peroxide (H2 O2 ) emission was measured fluorometrically. Detrusor citrate synthase activity was measured via enzyme activity kit and Western blots assessed the electron transport chain (ETC) protein content. RESULTS: HFD significantly increased body weight, adiposity, and blood glucose levels. HFD mice demonstrated increased voiding frequency and increased EFS-induced detrusor contractility. There were no changes in detrusor relaxation or cholinergic-medicated contraction. Mitochondrial respiration was decreased with HFD and H2 O 2 emission was increased. The relative amount of mitochondria in the detrusor was similar between groups. However, ETC complexes V and III were increased following HFD. CONCLUSIONS: Chronic HFD increased adiposity, lead to more frequent voiding, and enhanced EFS-mediated detrusor contractions. Mitochondrial respiration was decreased and H2 O 2 emission increased following HFD. Further research is required to determine if alterations in mitochondrial function could play a role in the development of HFD-induced bladder dysfunction.

Galanin Administration Partially Restores Erectile Function After Cavernous Nerve Injury and Mediates Endogenous Nitrergic Nerve Outgrowth In Vitro.

BACKGROUND: Previously, we found that the neuropeptide galanin was strongly upregulated soon after bilateral cavernous nerve injury (BCNI) and that galanin and its receptors were expressed in nitrergic erectile innervation. Galanin has been observed to exert neuroregenerative effects in dorsal root ganglion neurons, but evidence for these effects in the major pelvic ganglion (MPG) after BCNI is lacking. AIM: To evaluate the neurotropic effects of galanin receptor agonists and antagonists in vitro in nitrergic neurons and MPG and in vivo in rats after BCNI. METHODS: Male Sprague-Dawley rats underwent BCNI and sham surgery. Organ culture and single-cell neuron culture of the MPG were performed. Osmotic pump treatment with the galanin agonist in vivo and measurement of erectile response to electrostimulation after BCNI, immunohistochemical localization of galanin and receptors in the human neurovascular bundle, and myographic analysis of rat corpus cavernosum smooth muscle relaxation to galanin receptor agonists were investigated. OUTCOMES: Neurite outgrowth in vitro and erectile response to electrostimulation after BCNI in vivo, immunohistochemical localization of galanin and receptors, and penile muscle relaxation in vitro. RESULTS: Galanin showed neurotrophic action in vitro and inhibition of endogenous galanin significantly impaired neurite outgrowth in nitrergic but not in sympathetic MPG neurons. In vivo administration of a selective galanin receptor-2 agonist, M1145, resulted in partial recovery of erectile function (EF) after BCNI. Galanin did not act as a direct vasodilator on corpus cavernosum muscle strips. CLINICAL TRANSLATION: Endogenous neurotrophins such as galanin could be used as a strategy to improve EF for patients after BCNI from radical prostatectomy. STRENGTHS AND LIMITATIONS: We evaluated the effect of galanin on nerve regeneration and EF recovery in vivo and in vitro. Limitations include the lack of washout period for the in vivo experiment and absence of differences in the expression of neuronal markers between treatment groups. CONCLUSIONS: We identified galanin as a potential endogenous mechanism for nerve regeneration after BCNI, which could play a physiologic role in EF recovery after radical prostatectomy. In vivo treatment with exogenous galanin was beneficial in enhancing EF recovery after BCNI, but further research is necessary to understand the underlying mechanisms. Weyne E, Hannan JL, Gevaert T, et al. Galanin Administration Partially Restores Erectile Function After Cavernous Nerve Injury and Mediates Endogenous Nitrergic Nerve Outgrowth In Vitro. J Sex Med 2018;15:480-491.

NLRP3/IL-1ß mediates denervation during bladder outlet obstruction in rats.

AIMS: Denervation of the bladder is a detrimental consequence of bladder outlet obstruction (BOO). We have previously shown that, during BOO, inflammation triggered by the NLRP3 inflammasome in the urothelia mediates physiological bladder dysfunction and downstream fibrosis in rats. The aim of this study was to assess the effect of NLRP3-mediated inflammation on bladder denervation during BOO. METHODS: There were five groups of rats: (i) Control (no surgery); (ii) Sham-operated; (iii) BOO rats given vehicle; (iv) BOO rats given the NLRP3 inhibitor glyburide; and (v) BOO rats given the IL-1 receptor antagonist anakinra. BOO was constructed by ligating the urethra over a 1 mm catheter and removing the catheter. Medications were given prior to surgery and once daily for 12 days. Bladder sections were stained for PGP9.5, a pan-neuronal marker. Whole transverse sections were used to identify and count nerves while assessing cross-sectional area. For in vitro studies, pelvic ganglion neurons were isolated and treated with IL-1ß. After a 48 h incubation apoptosis, neurite length and branching were assessed. RESULTS: In obstructed bladders, the number of nerves decreased while total area increased, indicating a loss of cell number and/or branching. The decrease in nerve density was blocked by glyburide or anakinra, clearly implicating the NLRP3 pathway in denervation. In vitro analysis demonstrated that IL-1ß, a product of the inflammasome, induced apoptosis in pelvic ganglion neurons, suggesting one mechanism of BOO-induced denervation is NLRP3/IL-1ß triggered apoptosis. CONCLUSIONS: The NLRP3/IL-1ß-mediated inflammation pathway plays a significant role in denervation during BOO.

Enhanced Electrical Field Stimulated Nitrergic and Purinergic Vasoreactivity in Distal vs Proximal Internal Pudendal Arteries.

BACKGROUND: The internal pudendal arteries (IPAs) supply blood to the penis and are highly susceptible to vascular remodeling in rodent models of diabetes, hypertension, aging, and chronic kidney disease, thus contributing to erectile dysfunction. Interestingly, vascular remodeling primarily occurs in the distal and not in the proximal IPA, suggesting distinct local physiologic signaling differences within the IPA. AIM: To examine the role of purinergic signaling and neurotransmitter release by electrical field stimulation (EFS) in the regulation of proximal and distal IPA vascular tone. METHODS: Proximal and distal IPAs were mounted in wire myographs and vascular responses to phenylephrine, acetylcholine, and 2-(N,N-diethylamino)-diazenolate-2-oxide, diethyl-ammonium salt (DEA NONOate) were measured. EFS-mediated contraction and non-adrenergic non-cholinergic (NANC) relaxation were evaluated in the absence and presence of a nitric oxide synthase antagonist. Purinergic agonist and NANC relaxation responses were assessed in the presence and absence of P2X1 and P2Y1 antagonists. Protein expression of P2X1 and P2Y1 receptors was measured by western blot. MAIN OUTCOME MEASURES: Proximal and distal IPA contraction and relaxation were measured during increasing agonist administration and EFS in the presence and absence of antagonists. RESULTS: Proximal and distal IPA concentration response curves to phenylephrine, acetylcholine, and DEA NONOate did no differ. Interestingly, distal IPA exhibited greater EFS-mediated contraction and NANC relaxation compared with proximal IPA. Nitric oxide synthase inhibition completely inhibited distal IPA NANC relaxation but did not affect proximal IPA relaxation. P2X1 or P2Y1 receptor antagonism during NANC relaxation increased distal IPA relaxation but decreased proximal IPA relaxation. Combined P2X1 and P2Y1 receptor antagonism had no effect on proximal IPA relaxation but significantly increased distal IPA NANC relaxation. CLINICAL TRANSLATION: Understanding neurovascular regulation of IPA vascular tone through nitrergic and purinergic mechanisms could yield new therapeutic targets to improve IPA blood flow and treat vasculogenic erectile dysfunction. STRENGTHS AND LIMITATIONS: This study is the first to illustrate the differences in mechanisms responsible for regulating vascular tone in the proximal and distal IPAs. All presented findings are currently limited to ex vivo vascular function. CONCLUSION: The regulation of vascular tone differs regionally in the IPA. The distal IPA is controlled through neurotransmitter-mediated NO-dependent mechanisms and increased sensitivity to purinergic P2X1 and P2Y1 receptor inhibition. Odom MR, Pak ES, Brown DA, Hannan JL. Enhanced Electrical Field Stimulated Nitrergic and Purinergic Vasoreactivity in Distal vs Proximal Internal Pudendal Arteries. J Sex Med 2017;14:1285-1296.

M1 Macrophages Are Predominantly Recruited to the Major Pelvic Ganglion of the Rat Following Cavernous Nerve Injury.

INTRODUCTION: Neurogenic erectile dysfunction is a common sequela of radical prostatectomy. The etiology involves injury to the autonomic cavernous nerves, which arise from the major pelvic ganglion (MPG), and subsequent neuroinflammation, which leads to recruitment of macrophages to the injury site. Currently, two macrophage phenotypes are known: neurotoxic M1 macrophages and neuroprotective M2 macrophages. AIM: To examine whether bilateral cavernous nerve injury (BCNI) in a rat model of erectile dysfunction would increase recruitment of neurotoxic M1 macrophages to the MPG. METHODS: Male Sprague-Dawley rats underwent BCNI and the MPG was harvested at various time points after injury. The corpora cavernosa was used to evaluate tissue myographic responses to electrical field stimulation ex vivo. Quantitative real-time polymerase chain reaction was used to examine the gene expression of global macrophage markers, M1 macrophage markers, M2 macrophage markers, and cytokines and chemokines in the MPG. Mathematical calculation of the M1/M2 index was used to quantify macrophage changes temporally. Western blot of MPG tissues was used to evaluate the protein amount of M1 and M2 macrophage markers quantitatively. Immunohistochemistry staining of MPGs for CD68, CD86, and CD206 was used to characterize M1 and M2 macrophage infiltration. MAIN OUTCOME MEASURES: Corpora cavernosa responsiveness ex vivo; gene (quantitative real-time polymerase chain reaction) and protein (western blot) expressions of M1 and M2 markers, cytokines, and chemokines; and immunohistochemical localization of M1 and M2 macrophages. RESULTS: BCNI impaired the corporal parasympathetic-mediated relaxation response to electrical field stimulation and enhanced the contraction response to electrical field stimulation. Gene expression of proinflammatory (Il1b, Il16, Tnfa, Tgfb, Ccl2, Ccr2) and anti-inflammatory (Il10) cytokines was upregulated in the MPG 48 hours after injury. M1 markers (CD86, inducible nitric oxide synthase, interleukin-1ß) and M2 markers (CD206, arginase-1, interleukin-10) were increased after BCNI in the MPG, with the M1/M2 index above 1.0 indicating that more M1 than M2 macrophages were recruited to the MPG. Protein expression of the M1 macrophage marker (inducible nitric oxide synthase) was increased in MPGs after BCNI. However, the protein amount of M2 macrophage markers (arginase-1) remained unchanged. Immunohistochemical characterization demonstrated predominant increases in M1 (CD68+CD86+) macrophages in the MPG after BCNI. CONCLUSION: These results suggest that an increase in M1 macrophage infiltration of the MPG after BCNI is associated with impaired neurogenically mediated erectile tissue physiology ex vivo and thus has significant implications for cavernous nerve axonal repair. Future studies are needed to demonstrate that inhibition of M1 macrophage recruitment prevents erectile dysfunction after CNI.

Impaired contraction and decreased detrusor innervation in a female rat model of pelvic neuropraxia.

INTRODUCTION AND HYPOTHESIS: Bilateral pelvic nerve injury (BPNI) is a model of post-radical hysterectomy neuropraxia, a common sequela. This study assessed the time course of changes to detrusor autonomic innervation, smooth muscle (SM) content and cholinergic-mediated contraction post-BPNI. METHODS: Female Sprague-Dawley rats underwent BPNI or sham surgery and were evaluated 3, 7, 14, and 30 days post-BPNI (n = 8/group). Electrical field-stimulated (EFS) and carbachol-induced contractions were measured. Gene expression was assessed by qPCR for muscarinic receptor types 2 (M2) and 3 (M3), collagen type 1α1 and 3α1, and SM actin. Western blots measured M2 and M3 protein expression. Bladder sections were stained with Masson's trichrome for SM content and immunofluorescence staining for nerve terminals expressing vesicular acetylcholine transporter (VAChT), tyrosine hydroxylase (TH), and neuronal nitric oxide synthase (nNOS). RESULTS: Bilateral pelvic nerve injury caused larger bladders with less SM content and increased collagen type 1α1 and 3α1 gene expression. At early time points, cholinergic-mediated contraction increased, whereas EFS-mediated contraction decreased and returned to baseline by 30 days. Protein and gene expression of M3 was decreased 3 and 7 days post-BPNI, whereas M2 was unchanged. TH nerve terminals surrounding the detrusor decreased in all BPNI groups, whereas VAChT and nNOS terminals decreased 14 and 30 days post-BPNI. CONCLUSIONS: Bilateral pelvic nerve injury increased bladder size, impaired contractility, and decreased SM and autonomic innervation. Therapeutic strategies preventing nerve injury-mediated decline in neuronal input and SM content may prevent the development of a neurogenic bladder and improve quality of life after invasive pelvic surgery.

Translational Perspective on the Role of Testosterone in Sexual Function and Dysfunction.

INTRODUCTION: The biological importance of testosterone is generally accepted by the medical community; however, controversy focuses on its relevance to sexual function and the sexual response, and our understanding of the extent of its role in this area is evolving. AIM: To provide scientific evidence examining the role of testosterone at the cellular and molecular levels as it pertains to normal erectile physiology and the development of erectile dysfunction and to assist in guiding successful therapeutic interventions for androgen-dependent sexual dysfunction. METHODS: In this White Paper, the Basic Science Committee of the Sexual Medicine Society of North America assessed the current basic science literature examining the role of testosterone in sexual function and dysfunction. RESULTS: Testosterone plays an important role in sexual function through multiple processes: physiologic (stimulates activity of nitric oxide synthase), developmental (establishes and maintains the structural and functional integrity of the penis), neural (development, maintenance, function, and plasticity of the cavernous nerve and pelvic ganglia), therapeutically for dysfunctional regulation (beneficial effect on aging, diabetes, and prostatectomy), and phosphodiesterase type 5 inhibition (testosterone supplement to counteract phosphodiesterase type 5 inhibitor resistance). CONCLUSION: Despite controversies concerning testosterone with regard to sexual function, basic science studies provide incontrovertible evidence for a significant role of testosterone in sexual function and suggest that properly administered testosterone therapy is potentially advantageous for treating male sexual dysfunction.