ABSTRACT
Krause corpuscles, which were discovered in the 1850s, are specialized sensory structures found within the genitalia and other mucocutaneous tissues1-4. The physiological properties and functions of Krause corpuscles have remained unclear since their discovery. Here we report the anatomical and physiological properties of Krause corpuscles of the mouse clitoris and penis and their roles in sexual behaviour. We observed a high density of Krause corpuscles in the clitoris compared with the penis. Using mouse genetic tools, we identified two distinct somatosensory neuron subtypes that innervate Krause corpuscles of both the clitoris and penis and project to a unique sensory terminal region of the spinal cord. In vivo electrophysiology and calcium imaging experiments showed that both Krause corpuscle afferent types are A-fibre rapid-adapting low-threshold mechanoreceptors, optimally tuned to dynamic, light-touch and mechanical vibrations (40-80 Hz) applied to the clitoris or penis. Functionally, selective optogenetic activation of Krause corpuscle afferent terminals evoked penile erection in male mice and vaginal contraction in female mice, while genetic ablation of Krause corpuscles impaired intromission and ejaculation of males and reduced sexual receptivity of females. Thus, Krause corpuscles of the clitoris and penis are highly sensitive mechanical vibration detectors that mediate sexually dimorphic mating behaviours.
Subject(s)
Clitoris , Mechanoreceptors , Penis , Sexual Behavior, Animal , Touch , Vibration , Animals , Female , Male , Mice , Clitoris/innervation , Clitoris/physiology , Ejaculation/physiology , Mechanoreceptors/metabolism , Mechanoreceptors/physiology , Optogenetics , Penile Erection/physiology , Penis/innervation , Penis/physiology , Sexual Behavior, Animal/physiology , Spinal Cord/physiology , Spinal Cord/cytology , Touch/physiology , Vagina/physiology , Neurons/physiologyABSTRACT
OBJECTIVE: To assess pelvic floor muscle (PFM) strength and influencing factors among healthy women at different life stages. DESIGN: Multicentre cross-sectional study. SETTING: Fourteen hospitals in China. POPULATION: A total of 5040 healthy women allocated to the following groups (with 1680 women per group): premenopausal nulliparous, premenopausal parous and postmenopausal. METHODS: The PFM strength was evaluated by vaginal manometry. Multivariate logistic regression was used to determine the influencing factors for low PFM strength. MAIN OUTCOME MEASURES: Maximum voluntary contraction pressure (MVCP). RESULTS: The median MVCP values were 36, 35 and 35 cmH2O in premenopausal nulliparous (aged 19-51 years), premenopausal parous (aged 22-61 years), and postmenopausal (aged 40-86 years) women, respectively. In the premenopausal nulliparous group, physical work (odds ratio, OR 2.05) was the risk factor for low PFM strength, which may be related to the chronic increased abdominal pressure caused by physical work. In the premenopausal parous group, the number of vaginal deliveries (OR 1.28) and diabetes (OR 2.70) were risk factors for low PFM strength, whereas sexual intercourse (<2 times per week vs. none, OR 0.55; ≥2 times per week vs. none, OR 0.56) and PFM exercise (OR 0.50) may have protective effects. In the postmenopausal group, the number of vaginal deliveries (OR 1.32) and family history of pelvic organ prolapse (POP) (OR 1.83) were risk factors for low PFM strength. CONCLUSIONS: Physical work, vaginal delivery, diabetes and a family history of POP are all risk factors for low PFM strength, whereas PFM exercises and sexual life can have a protective effect. The importance of these factors varies at different stages of a woman's life.
Subject(s)
Manometry , Muscle Strength , Pelvic Floor , Postmenopause , Premenopause , Vagina , Humans , Female , Middle Aged , Cross-Sectional Studies , Pelvic Floor/physiology , Adult , Manometry/methods , Muscle Strength/physiology , Aged , Postmenopause/physiology , Premenopause/physiology , Vagina/physiology , Risk Factors , Aged, 80 and over , Young Adult , Parity , China/epidemiology , Muscle Contraction/physiology , PregnancyABSTRACT
OBJECTIVE: To investigate the feasibility of laser speckle contrast imaging (LSCI) for monitoring urethral blood flow (UBF). MATERIALS AND METHODS: In this study, 18 healthy, virgin female Sprague-Dawley rats aged 8-week-old were used. The animals were divided into the sham group (n = 9) and the vaginal distension (VD) group (n = 9). The sham group underwent one catheterization of the vagina without distension and the VD group underwent one VD. Following the VD or sham treatment for one week, LSCI assessment of urethral blood flow was performed during bladder filling and leak point pressure (LPP) process. RESULTS: During the LPP process, in the VD group, the mean LPP was significantly lower than in the sham group (p < 0.05) and the mean UBF level was also significantly lower than in the sham group (p < 0.05) in the LPP condition. The mean relative change of UBF (Δ Flow) was significantly different between the sham group and VD group. The value was 0.646 ± 0.229 and 0.295 ± 0.19, respectively (p < 0.05). During the bladder filling process, the VD group had a significant lower mean UBF level than the sham group under full bladder conditions (p = 0.008). The mean ΔFlow was also significantly lower than in the sham group. The value was 0.115 ± 0.121 and 0.375 ± 0.127, respectively (p = 0.016). CONCLUSIONS: The results confirmed that LSCI was able to determine UBF in female rats. The VD group had lower baseline UBF and lower increases in UBF during bladder filling and LPP process compared with the sham group.
Subject(s)
Laser Speckle Contrast Imaging , Urinary Incontinence, Stress , Rats , Female , Animals , Rats, Sprague-Dawley , Urinary Incontinence, Stress/therapy , Vagina/physiology , Urethra/physiology , Disease Models, AnimalABSTRACT
BACKGROUND: Although oral contraceptive pills (OCPs) have been associated with decrements in self-reported genital arousal and vaginal lubrication, 1,2 little is known about how these outcomes vary across types of OCPs. AIM: The present study examined differences in physiological lubrication and vaginal blood flow, as well as rates of self-reported vulvovaginal atrophy and female sexual arousal disorder, among women using OCPs with varying androgenic properties. METHODS: Participants in this study were 130 women: 59 naturally cycling control women, 50 women taking androgenic OCPs, and 21 women taking antiandrogenic OCPs. Participants watched sexual films while their sexual arousal responses were measured, completed questionnaires, and participated in a clinical interview. OUTCOMES: Vaginal blood flow, vaginal lubrication, self-reported vulvovaginal atrophy, and female sexual arousal disorder were assessed. RESULTS: Results indicated deficits in vaginal pulse amplitude and lubrication for women taking either form of OCP, with marked inhibitory effects found in women taking antiandrogenic OCPs. Rates of self-reported vulvovaginal atrophy and female sexual arousal disorder were also significantly greater in the antiandrogenic group compared with the control group. CLINICAL IMPLICATIONS: It is recommended that prescribing clinicians consult patients on such physiological effects of OCPs. STRENGTHS AND LIMITATIONS: To our knowledge, this was the first study to compare multiple measures of physiological sexual arousal across groups of women taking OCPs with varying hormonal profiles. Because all OCPs included in this study contained low doses of ethinylestradiol, we were able to identify the specific effects of the androgenic properties on women's sexual arousal responses. However, the self-administered lubrication test strip was subject to user error. Additionally, the generalizability of findings is limited by the largely heterosexual and college-aged sample. CONCLUSION: Compared with naturally cycling women, women taking OCPs that contain antiandrogenic progestins experienced decreased vaginal blood flow and lubrication as well as higher rates of self-reported vaginal bleeding and female sexual arousal disorder.
Subject(s)
Sexual Arousal , Sexual Dysfunction, Physiological , Female , Humans , Young Adult , Sexual Behavior/physiology , Contraceptives, Oral , Vagina/physiology , Sexual Dysfunction, Physiological/drug therapy , AtrophyABSTRACT
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.
Subject(s)
Cervix Uteri , Sexual Behavior , Humans , Female , Pain , Pleasure , Sensation , Vagina/physiologyABSTRACT
BACKGROUND: Sex steroids have been demonstrated as important modulators of vaginal function. The RhoA/ROCK calcium-sensitizing pathway plays a role in genital smooth muscle contractile mechanism, but its regulation has never been elucidated. AIM: This study investigated the sex steroid regulation of the vaginal smooth muscle RhoA/ROCK pathway using a validated animal model. METHODS: Ovariectomized (OVX) Sprague-Dawley rats were treated with 17ß-estradiol (E2), testosterone (T), and T with letrozole (T + L) and compared with intact animals. Contractility studies were performed to test the effect of the ROCK inhibitor Y-27632 and the nitric oxide (NO) synthase inhibitor L-NAME. In vaginal tissues, ROCK1 immunolocalization was investigated; mRNA expression was analyzed by semiquantitative reverse transcriptase-polymerase chain reaction; and RhoA membrane translocation was evaluated by Western blot. Finally, rat vaginal smooth muscle cells (rvSMCs) were isolated from the distal vagina of intact and OVX animals, and quantification of the RhoA inhibitory protein RhoGDI was performed after stimulation with NO donor sodium nitroprusside, with or without administration of the soluble guanylate cyclase inhibitor ODQ or PRKG1 inhibitor KT5823. OUTCOMES: Androgens are critical in inhibiting the RhoA/ROCK pathway of the smooth muscle compartment in the distal vagina. RESULTS: ROCK1 was immunolocalized in the smooth muscle bundles and blood vessel wall of the vagina, with weak positivity detected in the epithelium. Y-27632 induced a dose-dependent relaxation of noradrenaline precontracted vaginal strips, decreased by OVX and restored by E2, while T and T + L decreased it below the OVX level. In Western blot analysis, when compared with control, OVX significantly induced RhoA activation, as revealed by its membrane translocation, with T reverting it at a level significantly lower than in controls. This effect was not exerted by E2. Abolishing NO formation via L-NAME increased Y-27632 responsiveness in the OVX + T group; L-NAME had partial effects in controls while not modulating Y-27632 responsiveness in the OVX and OVX + E2 groups. Finally, stimulation of rvSMCs from control animals with sodium nitroprusside significantly increased RhoGDI protein expression, counteracted by ODQ and partially by KT5823 incubation; no effect was observed in rvSMCs from OVX rats. CLINICAL IMPLICATIONS: Androgens, by inhibiting the RhoA/ROCK pathway, could positively contribute to vaginal smooth muscle relaxation, favoring sexual intercourse. STRENGTHS AND LIMITATIONS: This study describes the role of androgens in maintaining vaginal well-being. The absence of a sham-operated animal group and the use of the only intact animal as control represented a limitation to the study.
Subject(s)
Androgens , Testosterone , Female , Rats , Animals , Humans , Rats, Sprague-Dawley , Nitroprusside , NG-Nitroarginine Methyl Ester , Estradiol/pharmacology , Letrozole , Vagina/physiology , Enzyme Inhibitors , rho-Specific Guanine Nucleotide Dissociation Inhibitors/metabolism , Ovariectomy , rhoA GTP-Binding Protein/metabolismABSTRACT
BACKGROUND: Vaginal lubrication and contractions are among the top difficulties affecting sexual intercourse in women after spinal cord injury. AIM: This study aimed at determining if pudendal nerve stimulation (PNS) can improve vaginal lubrication and induce increases in vaginal pressure. METHODS: In anesthetized cats, a small piece of cotton was inserted into the vagina for 10 minutes with or without PNS to measure vaginal wetness by the weight increase of the vaginal cotton. Then, a small balloon catheter was inserted into the vagina to measure the pressure increase induced by PNS. Intensity response of the vagina to PNS (30 Hz, 0.2 ms, 5 seconds) was determined at 1-4 times of intensity threshold (T) for PNS to induce an observable vaginal pressure increase. Frequency response was determined at 2T intensity in a range of PNS frequencies (5-50 Hz). Finally, fatigue in vaginal pressure was determined by applying PNS (30 Hz, 2T) either continuously or intermittently (5 seconds on and 5 seconds off) for 4 minutes. OUTCOMES: The effectiveness of PNS in increasing vaginal wetness and pressure is evaluated. RESULTS: PNS significantly (P = .0327) increased the measurement of vaginal wetness from 15.8 ± 3.8 mg during control without stimulation to 32.4 ± 4.7 mg after stimulation. Vaginal pressure increased as PNS intensity or frequency increased. PNS (30 Hz, 2T) induced vaginal pressure increase ≥80% of the maximal response. Intermittent PNS induced significantly (P = .0354) smaller fatigue (45.6 ± 3.7%) in vaginal pressure than continuous PNS (69.1 ± 3.0%) during the 4-minute stimulation. CLINICAL TRANSLATION: This study raises the possibility of developing a novel pudendal neuromodulation device to improve female sexual function after spinal cord injury. STRENGTHS & LIMITATIONS: This study provides preclinical data supporting the development of a novel pudendal neuromodulation device. The limitation includes the lack of chemical analysis of the vaginal secretion. CONCLUSION: PNS can improve vaginal lubrication and induce increases in vaginal pressure. Chen J, Zhong Y, Wang J, et al. Vaginal Lubrication and Pressure Increase Induced by Pudendal Nerve Stimulation in Cats. J Sex Med 2022;19:1517-1523.
Subject(s)
Pudendal Nerve , Vagina , Animals , Cats , Electric Stimulation , Female , Lubrication , Muscle Fatigue , Pressure , Pudendal Nerve/physiology , Vagina/physiologyABSTRACT
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.
Subject(s)
Cardiovascular Diseases , Diabetes Mellitus, Type 2 , Metabolic Syndrome , Sexual Dysfunction, Physiological , Animals , Cardiovascular Diseases/complications , Clitoris/physiology , Female , Metabolic Syndrome/complications , Sexual Dysfunction, Physiological/etiology , Vagina/physiologyABSTRACT
Research conducted in our laboratory and in other laboratories has revealed that (1) women's genital responses to visual and auditory stimuli are strongly affected by the presence of sexual cues, but that (2) specific sexual cues (e.g., gender of actors, the presence of sexual violence) often have little impact on the magnitude of the responses-that is, similar genital responses are observed to very different sexual stimuli. In addition, (3) women's genital responses do not strongly correspond with self-reported sexual partner and activity preferences, or (4) with self-reported sexual arousal during the presentation of sexual stimuli. Taken together, these facts represent a puzzle, especially considering that men's genital responses are highly affected by specific sexual cues and strongly correspond to stated preferences and self-reported sexual arousal. One hypothesis to explain female low cue-specificity and low concordance (relative to men) is the preparation hypothesis: Women's indiscriminate genital responses serve a protective function. That is, they do not indicate or necessarily promote sexual interest and motivation, but rather prepare the vaginal lumen for possible sexual activity and therefore prevent injuries that may occur as a result of penetration. We review evidence for and against this hypothesis. We conclude that the evidence is favorable but not entirely convincing, and more work is required to reach a firm conclusion. We offer directions for future research.
Subject(s)
Arousal , Laboratories , Arousal/physiology , Female , Humans , Male , Men , Sexual Behavior/physiology , Vagina/physiologyABSTRACT
OBJECTIVE: To assess vaginal health, endometrial thickness, and changes in bone markers in postmenopausal women with vulvovaginal atrophy (VVA) treated with 60 mg/day of ospemifene under routine clinical practice. METHODS: The AYSEX study is a Spanish observational and prospective study performed in one center in which 5 gynecologists recruited postmenopausal women with VVA in routine clinical practice treated continuously with ospemifene 60 mg/day for 12 months as an appropriate therapeutic option. This article refers to the 3- and 6-months analysis. Vaginal health was assessed by pH and using Vaginal Health Index (VHI) at baseline and 3 months later. Endometrial thickness, measured by vaginal ultrasonography, and bone resorption marker (CTx) were assessed at baseline and 6 months later. RESULTS: A total of 100 postmenopausal women cytologically and clinically diagnosed with VVA were included in the study. After 3 months of treatment with ospemifene, pH improved from 6.1 to 4.5 (p < .0001), and VHI improved from 10 to 19 points (p < .0001). The percentage of patients with VVA according to VHI decreased from 100% to 5.2% (p < .0001). After 6 months, mean CTx levels decreased from 0.42 pg/ml at baseline to 0.37 pg/ml 6 months later (p = .0018), and mean endometrial thickness changed from 2.24 to 2.15 mm (p = .6066). CONCLUSIONS: Up to date, this is the only prospective and observational study with ospemifene in routine clinical practice conditions and confirms the results previously reported from randomized controlled clinical trials, improving VVA, not increasing endometrial thickness, and decreasing CTx levels by exerting an anti-resorptive function.
Subject(s)
Bone and Bones/physiology , Endometrium/anatomy & histology , Postmenopause/physiology , Tamoxifen/analogs & derivatives , Vagina/physiology , Biomarkers/blood , Bone Resorption , Bone and Bones/drug effects , Endometrium/drug effects , Female , Humans , Postmenopause/drug effects , Prospective Studies , Tamoxifen/administration & dosage , Ultrasonography , Vagina/drug effectsABSTRACT
This review focuses on the diagnosis and management of menopause, highlighting both hormonal and nonhormonal treatment options. In particular, the article focuses on recent data on the risks and benefits of hormone therapy to help clinicians better counsel their patients about decision making with regard to understanding and treating menopause symptoms.
Subject(s)
Menopause/physiology , Breast Neoplasms/etiology , Cardiovascular Diseases/prevention & control , Cognition Disorders/etiology , Contraindications, Drug , Estrogen Replacement Therapy/adverse effects , Female , Healthy Lifestyle , Hot Flashes/drug therapy , Hot Flashes/therapy , Humans , Menopause/blood , Menopause/psychology , Osteoporosis, Postmenopausal/prevention & control , Patient Education as Topic , Risk Assessment , Selective Serotonin Reuptake Inhibitors/therapeutic use , Sweating/physiology , Vagina/physiology , Vasomotor System/physiologyABSTRACT
While human vaginal pH in childbearing-age women is conclusively acidic, the mouse vaginal pH is reported as being near neutral. However, this information appears to be somewhat anecdotal with respect to vulvovaginal candidiasis, as such claims in the literature frequently lack citations of studies that specifically address this physiological factor. Given the disparate pH between mice and humans, the role of exogenous hormones and colonization by the fungal pathogen Candida albicans in shaping vaginal pH was assessed. Use of a convenient modified vaginal lavage technique with the pH indicator dye phenol red demonstrated that indeed vaginal pH was near neutral (7.2 ± 0.24) and was not altered by delivery of progesterone or estrogen in C57BL/6 mice. These trends were conserved in DBA/2 and CD-1 mouse backgrounds, commonly used in the mouse model of vaginitis. It was also determined that vaginal colonization with C. albicans did not alter the globally neutral vaginal pH over the course of one week. Construction and validation of a C. albicans reporter strain expressing GFPy, driven by the pH-responsive PHR1 promoter, confirmed the murine vaginal pH to be at least ≥6.0. Collectively, our data convincingly demonstrate a stable and conserved near neutrality of the mouse vaginal pH during vulvovaginal candidiasis and should serve as a definitive source for future reference. Implications and rationale for disparate pH in this model system are also discussed.
Subject(s)
Candidiasis, Vulvovaginal/microbiology , Candidiasis, Vulvovaginal/physiopathology , Estradiol/physiology , Hydrogen-Ion Concentration/drug effects , Vagina/physiology , Adult , Animals , Disease Models, Animal , Female , Humans , Mice , Mice, Inbred C57BL , Mice, Inbred DBAABSTRACT
Changes in vaginal blood flow and lubrication are primary components of physiological sexual arousal in women. Despite the existence of well-established tools for measuring vaginal blood flow, there is not yet a consistently implemented measure of physiological lubrication. To address this methodological gap, researchers have begun examining the utility of litmus test strips, primarily in sexually healthy women. The present study builds on this work by examining the utility of an alternative tool, the Schirmer Tear Test strips, in women with (n = 32) and without (n = 32) sexual arousal concerns. Significant increases in physiological lubrication were found in response to a sexual film, and these changes were moderately correlated with self-reported genital arousal (r = .41) and lubrication (r = .30). No between-group differences in lubrication were observed. These results indicate the Schirmer Tear Test strips are sensitive enough to detect increases in lubrication and may be valuable in clinical and research assessments of female sexual arousal.
Subject(s)
Bodily Secretions/physiology , Cervix Mucus/physiology , Sexual Arousal , Vagina/physiology , Adult , Feasibility Studies , Female , Humans , Lubrication , Middle Aged , Reagent Strips/administration & dosage , Self Report , Young AdultABSTRACT
Objectives. The onset of puberty in humans is followed by an increase in insulin resistance and this transient phenomenon decreases at the end of the puberty. However, the insulin resistance during puberty has not been described in mice. Thus, in the present study we performed a temporal characterization of the development of insulin resistance during puberty in male and female C57BL/6 mice.Methods. From the fourth week of life male (n=18) and female (n=32) C57BL/6 wild-type mice were weekly subjected to insulin tolerance tests until the seventh week of life. Blood glucose levels were determined using a glucose meter through samples collected from the tail tip. Vaginal opening was assessed daily in female mice. Preputial separation was determined in a subgroup of males.Results. We observed a transient increase in the area under the curve of the insulin tolerance tests and in basal glycemia in female mice at the time of vaginal opening (between the fourth and fifth week of life) compared with previous and subsequent weeks of pubertal development. In contrast, male mice show no changes in insulin sensitivity during puberty.Conclusions. Our findings demonstrate that the insulin resistance at puberty can also be observed in female mice and this peak occurs at the time of vaginal opening. Our temporal characterization can be used as a reference for future studies that aim to study glucose homeostasis during puberty in rodents.
Subject(s)
Insulin Resistance/physiology , Sexual Maturation/physiology , Animals , Blood Glucose/analysis , Female , Insulin/administration & dosage , Male , Mice , Mice, Inbred C57BL , Sex Characteristics , Vagina/physiologyABSTRACT
BACKGROUND: Evidence suggests that intravaginal practices (IVPs) women use to cleanse their vagina or enhance sexual pleasure may be associated with unhealthy changes in the vaginal microbiome (VM). However, the effects of these practices in postmenopausal women are unknown. OBJECTIVES: The objective of this pilot study was to characterize the VM communities of postmenopausal women, identify types and frequency of IVPs, and explore associations between the VM and IVPs in postmenopausal women. METHODS: We analyzed the VM data of 21 postmenopausal women in Atlanta, Georgia, from vaginal swabs collected at a routine gynecological visit. 16S rRNA gene sequencing in the V3-V4 region was used to characterize the VM. In addition, we described the IVPs of these women, identified by using our newly developed instrument: the Vaginal Cleansing Practices Questionnaire. The associations between the VM and IVPs were explored by comparing the alpha diversities, beta diversities, and the relative abundances at both the community level and individual genus level. RESULTS: The most abundant known bacterial genus found in the VM samples was Lactobacillus (35.7%), followed by Prevotella (21.4%). Eleven women (52%) reported using at least one type of IVP since menopause. The most common type of IVP was soap and water to clean inside the vagina. The use of IVPs was not associated with any alpha diversity metric, including Shannon index, inverse Simpson index, and Chao1 index; beta diversity metric, including Bray-Curtis and Jaccard distances; nor relative abundances at the community and individual genus level. Sociodemographic factors were also not associated with any alpha diversity metric. DISCUSSION: Clinicians must assess IVPs and other vaginal and sexual hygiene practices of women of all ages to educate and promote healthy behaviors. More than half of the postmenopausal women in this pilot study use IVPs. Understanding the reasoning behind participants' use of IVPs and their perceptions of the possible effects of these practices will require further research. Although the small sample did not show associations with the VM, more extensive studies are warranted.
Subject(s)
Menopause/physiology , Microbiota/physiology , Vagina/microbiology , Aged , Female , Georgia , Humans , Middle Aged , Pilot Projects , Surveys and Questionnaires , Vagina/physiologyABSTRACT
The objective of this study was to investigate three different calving detection systems in order to assess and compare their efficiency. The study was conducted at a large-scale dairy farm involving 54 Holstein-Friesian dairy cows and heifers. Animals were fitted with multiple devices: a rumination measuring device (Ruminact® (RA)), an intravaginal thermometer (Vel'Phone® (VP)) and a tail movement sensor (Moocall® (MC)) 5 to 7 days before expected calving and were removed after parturition. RA detects rumination time (RT) and calculates it in 2-hr intervals. VP detects a decrease in vaginal temperature that might indicate calving within 48 hr and the drop in temperature resulting from the expulsion of the device at calving (EXP message). MC detected increased tail movements and if they persisted for one hour, 1HA message was sent. If they continued during the subsequent hour, then 2HA message was sent. Messages sent by MC within 4 hr before calving (C4) were selected retrospectively as true positives for the prediction of calving, using the significant changes in RT as a baseline. All other messages were categorized as false positive. The mean value of RT decreased in a non-significant manner between interval -22 and -4 before calving. Significant decrease of RT was detectable between the two intervals of -4 and -2 before calving (24.7 ± 18.6 min/2 hr and 14.0 ± 13.0 min/2 hr, respectively). There was no significant difference between RT of primiparous and multiparous animals. EXP messages were accurate (positive predictive value 100%) indicators of the onset of calving. We received on average 12.7 ± 15.2 messages/animal (11.0 ± 10.1 and 16.6 ± 22.2 for cows and heifers, respectively). Positive predictive value was 12.6%. The number of false-positive messages was significantly higher in heifers. All three automatic systems could be used in a large-scale farm environment.
Subject(s)
Cattle , Parturition/physiology , Remote Sensing Technology/veterinary , Accelerometry/veterinary , Animals , Dairying/methods , Female , Hungary , Parity , Pregnancy , Remote Sensing Technology/instrumentation , Rumination, Digestive , Tail , Thermometry/instrumentation , Vagina/physiologyABSTRACT
A brief survey of how the news media reported and misreported on the publication of the review that revealed the overlooked empirical evidence for the reproductive function of the human clitoris.
Subject(s)
Arousal/physiology , Clitoris/physiology , Orgasm/physiology , Reproduction/physiology , Vagina/physiology , Female , HumansABSTRACT
The uterine first-pass effect occurs when drugs are delivered vaginally. However, the effect of vaginally administered recombinant human follicle-stimulating hormone (rhFSH) on ovarian folliculogenesis and endometrial receptivity is not well established. We aimed to compare the efficacy of rhFSH administered vaginally and abdominally in clinical in vitro fertilization (IVF) treatment, pharmacokinetic study, and animal study. In IVF treatment, the number of oocytes retrieved, endometrial thickness and uterine artery blood perfusion were not different between women who received the rhFSH either vaginally or abdominally. For serum pharmacokinetic parameters, significantly lower Tmax, clearance, and higher AUC and T1/2_elimination of rhFSH were observed in women who received rhFSH vaginally, but urine parameters were not different. Immature female rats that received daily abdominal or vaginal injections (1 IU twice daily for 4 days) or intermittent vaginal injections (4 IU every other day for two doses) of rhFSH had more total follicles than the control group. In addition, the serum progesterone and progesterone receptors in the local endometrium were significantly higher in the groups treated with intermittent abdominal or vaginal injection of rhFSH, compared with those who recieved daily injection. In summary, vaginal administration of rhFSH may provide an alternative treatment regimen in women receiving IVF.
Subject(s)
Endometrium/physiology , Fertilization in Vitro/methods , Follicle Stimulating Hormone, Human/administration & dosage , Infertility, Female/therapy , Ovarian Follicle/cytology , Recombinant Proteins/administration & dosage , Uterus/physiology , Adult , Animals , Cross-Over Studies , Endometrium/drug effects , Female , Humans , Middle Aged , Ovarian Follicle/physiology , Rats , Rats, Sprague-Dawley , Sperm Injections, Intracytoplasmic , Uterus/drug effects , Vagina/drug effects , Vagina/physiologyABSTRACT
INTRODUCTION: Several studies demonstrated that genital arousal and enhanced positive affect toward neutral stimuli due to sexual conditioning did not extinguish during a brief extinction phase, but other studies showed contrasting results. Possible resistance to extinction of conditioned human sexual response has, however, not been studied using extensive extinction trials. AIM: To study resistance to extinction of conditioned sexual response in men and women. METHODS: Healthy sexually functional men (N = 34) and women (N = 32) participated in a differential conditioning experiment, with neutral pictures as conditioned stimuli (CSs) and genital vibrostimulation as unconditioned stimulus. Only one CS (the CS+) was followed by the unconditioned stimulus during the acquisition phase. MAIN OUTCOME MEASURE: Penile circumference and vaginal pulse amplitude were assessed, and ratings of affective value and subjective sexual arousal were obtained. In addition, a stimulus response compatibility task was included to assess automatic approach and avoidance tendencies. RESULTS: Men and women rated the CS+ as more positive than the CS- during all 24 extinction trials and demonstrated a slight tendency to approach the CS+ directly after the extinction procedure. Participants rated the CS+ as more sexually arousing than the CS- during 20 extinction trials. No evidence was found for conditioned genital sexual response. CLINICAL IMPLICATIONS: Learned sexual evaluations may be difficult to modify through an extinction procedure; therefore, unwanted but persistent subjective sexual evaluations may be better targeted by interventions such as the deployment of emotion regulation strategies. STRENGTH & LIMITATIONS: Extensive extinction trials were used; however, only relatively short-term effects within one experimental session were studied and there was no (unpaired) control condition. CONCLUSION: The results provide evidence that conditioned sexual likes are relatively persistent, also at the behavioral level. Both S, Brom M, Laan E, et al. Evidence for Persistence of Sexual Evaluative Learning Effects. J Sex Med 2020;17:505-517.
Subject(s)
Conditioning, Classical/physiology , Libido/physiology , Adolescent , Adult , Arousal/physiology , Emotions/physiology , Female , Heart Rate/physiology , Humans , Male , Vagina/physiology , Young AdultABSTRACT
INTRODUCTION: The vaginal photoplethysmograph (VPP) is a reusable intravaginal device often employed in sexual psychophysiology studies to assess changes in vaginal blood flow, an indicator of sexual arousal. AIM: To test whether placing a disposable cover on the VPP probe impacts the acquired data. A condom cover would reduce risk of disease transmission and likely increase participant comfort but may negatively impact the VPP signal. METHOD: The genital responses of 25 cisgender women (mean age = 21.3 years, standard deviation = 2.6) were assessed with VPP in a within-subjects design with 2 conditions-with and without a polyisoprene condom cover. Sexual responses were elicited by audiovisual film clips that varied in erotic intensity: nonsexual (nonsexual male-female interaction), low-intensity sexual (nude exercise), and high-intensity sexual (male-female intercourse). Women continuously rated their sexual arousal during stimulus presentations. MAIN OUTCOME MEASURE: Change in vaginal pulse amplitude and also self-reported sexual arousal. RESULTS: The magnitude of sexual response to each stimulus category and the overall pattern of results were found to be highly similar in the cover-off and cover-on conditions. The high-intensity sexual stimulus category elicited a greater sexual response than all other categories. The low-intensity sexual category elicited a (small) genital response in only the cover-on condition, although we suspect this is a spurious finding. There was no difference in the average number of edited movement artifacts across conditions. CLINICAL IMPLICATIONS: Potential benefits of encasing the VPP probe with a protective cover include enhanced participant safety and comfort, especially if assessing genital responses of high-risk or immunocompromised samples. The use of a cover complies with current guidelines for reprocessing semi-critical medical devices (eg, vaginal ultrasound probes) in many regions. STRENGTHS & LIMITATIONS: Although the idea of a VPP probe cover had been discussed among sexual psychophysiology researchers, this is the first study to empirically test whether a cover could jeopardize VPP data. Potential limitations include the use of a 10-Hz VPP sampling rate and a cover that was not tailored to the size of the VPP probe. CONCLUSION: Placing a protective cover on the VPP probe did not appear to meaningfully impact sexual arousal or the VPP data. Based on these results and the potential advantages of a protective cover, researchers may wish to integrate the use a condom cover in their experiment protocols and clinical applications. Sawatsky ML, Lalumière ML. Effect of a Condom Cover on Vaginal Photoplethysmographic Responses. J Sex Med 2020; 17:702-715.