An Algorithm to Personalize Nerve Sparing in Men with Unilateral High-Risk Prostate Cancer.

PURPOSE: Current guidelines do not provide strong recommendations on preservation of the neurovascular bundles during radical prostatectomy in case of high-risk (HR) prostate cancer and/or suspicious extraprostatic extension (EPE). We aimed to evaluate when, in case of unilateral HR disease, contralateral nerve sparing (NS) should be considered or not. MATERIALS AND METHODS: Within a multi-institutional data set we selected patients with unilateral HR prostate cancer, defined as unilateral EPE and/or seminal vesicle invasion (SVI) on multiparametric (mp) magnetic resonance imaging (MRI), or unilateral International Society of Urologic Pathologists (ISUP) 4-5 or prostate specific antigen ≥20 ng/ml. To evaluate when to perform NS based on the risk of contralateral EPE, we relied on chi-square automated interaction detection, a recursive machine-learning partitioning algorithm developed to identify risk groups, which was fit to predict the presence of EPE on final pathology, contralaterally to the prostate lobe with HR disease. RESULTS: A total of 705 patients were identified. Contralateral EPE was documented in 87 patients (12%). Chi-square automated interaction detection identified 3 groups, consisting of 1) absence of SVI on mpMRI and index lesion diameter ≤15 mm, 2) index lesion diameter ≤15 mm and contralateral ISUP 2-3 or index lesion diameter >15 mm and negative contralateral biopsy or ISUP 1, and 3) SVI on mpMRI or index lesion diameter >15 mm and contralateral biopsy ISUP 2-3. We named those groups as low, intermediate and high-risk, respectively, for contralateral EPE. The rate of EPE and positive surgical margins across the groups were 4.8%, 14% and 26%, and 5.6%, 13% and 18%, respectively. CONCLUSIONS: Our study challenges current guidelines by proving that wide bilateral excision in men with unilateral HR disease is not justified. Pending external validation, we propose performing NS and incremental NS in case of contralateral low and intermediate EPE risk, respectively.

The distribution of nerves supplying the testis, epididymis and accessory sex glands of Suncus murinus.

Chronic testicular pain remains an important challenge for urologists. Investigation of the innervation of male gonads thus becomes essential for deepening our understanding of their regulatory roles in male reproductive physiology and pathophysiology. Studies of testicular innervation are mainly limited to the intratesticular peptidergic nerves of the testis by immunohistochemical and acetylcholinesterase histochemical investigations in some animals. Little is known about the detailed, overall distribution in general experimental animal testis. In this study, the distribution of nerves supplying the testis, epididymis and accessory sex glands of Suncus murinus was investigated by whole mount immunohistochemistry staining using a neurofilament protein antibody. Testicular nerves arose through three routes: nerves deriving from the mesenteric and renal plexuses accompanied the testicular artery, entering into the testicular hilum through the superior ligament of the testis. The nerves originating from the hypogastric plexus then ran along the internal iliac artery, deferential artery, and passed through the mesoductus deferens or mesoepididymis, innervating the cauda and corpus of the epididymis, the vas deferens and the inferior pole of the testis. The third route arose from the pelvic plexus, distributed in the seminal vesicle and the prostate. The density of nerve fibers was higher in the cauda epididymidis than in the testis, and more abundant in the vas deferens. The different origins and distribution densities of testicular nerves in S. murinus may serve different neuronal regulatory functions, and, therefore, S. murinus may be an important model animal for understanding the different characteristics of testicular pain.

Site-dependent differences in the composite fibers of male pelvic plexus branches: an immunohistochemical analysis of donated elderly cadavers.

BACKGROUND: Although the pelvic autonomic plexus branches are considered to be a mixture of sympathetic and parasympathetic nerves, little is known regarding the composite fibers of the pelvic plexus branches. This study aimed to investigate the immunohistochemical features of sympathetic and parasympathetic nerves in the pelvic autonomic plexus branches. METHODS: Using 10 donated elderly male cadavers, the detailed topohistology of nerve fibers at and around the bladder, seminal vesicle, prostate, and rectum was examined. Neuronal nitric oxide synthase (nNOS) and vasoactive intestinal polypeptide (VIP) were used as parasympathetic nerve markers; tyrosine hydroxylase (TH) was used as a sympathetic nerve marker. The myenteric plexus of the colon was utilized as a positive control. RESULTS: Most nerve fibers in the bladder, seminal vesicle, prostate, and rectum were both nNOS- and TH-positive. Thus, pelvic plexus branches were classified into two types: 1) triple-positive mixed nerves (nNOS+, VIP+, TH+, thick myelinated fibers + or -) and 2) double-positive mixed nerves (nNOS+, VIP-, TH+, thick myelinated fibers + or -). Notably, triple-positive nerves were localized within the posterosuperior part of the plexus (near the rectum) and travelled anteroinferiorly toward the posterolateral corner of the prostate. The posteriorly and inferiorly located nerves were predominantly composed of parasympathetic, rather than sympathetic, fibers. In contrast, nerve fibers within and along the bladder and seminal vesicle contained either no or few VIP-positive nerves. These superiorly located nerves were characterized by clear sympathetic nerve dominance. CONCLUSIONS: The nerves of the pelvic plexus branches were clearly classified into nerves around the bladder and seminal vesicle (VIP-negative) and nerves around the prostate (VIP-positive). Although nNOS- and VIP-positive nerve fibers are candidate cavernous nerves, cavernous nerve identity cannot be definitively concluded for these nerves in the periprostatic region.

The anatomy of the male inferior hypogastric plexus: What should we know for nerve sparing surgery.

The aim of this study was to investigate the nerve supply to the structures in the male lesser pelvis and review its clinical relevance, especially during nerve sparing surgery. Three formalin-embalmed and 16 Thiel-embalmed male hemipelves were used. They were microdissected after repeated treatments with nitric acid diluted 1:10 with milliQ-water. The inferior hypogastric plexus (IHP) is a fan-like structure lateral from the rectum on the fascia of the levator ani. Nerves emerging from the proximal, solid part of the plexus follow the internal iliacal vessels and reach the prostate from dorsolateral. The innervation of the urethra and the corpora cavernosa derives from two origins: one follows the ejaculatory duct and the seminal vesicle, reaching the proximal urethra and the prostate from dorsal; the other follows the inferior vesical artery to reach the prostate from lateral, and then forms the neurovascular bundle on both sides of the prostatic fascia, spreading to the pelvic floor muscles and the corpora cavernosa along with the distal urethra. A connection between the two parts was demonstrated in approximately one third of the samples investigated. The nerve supply to the urinary bladder, the urethra, and the corpora cavernosa emerges mainly from the IHP. The innervation of the proximal urethra and its autonomic muscular structures has a dorsal (ejaculatory duct) and lateral (inferior vesical artery) origin. To maintain good erectile and continence function it is important to save both the dorsal and lateral neurovascular roots. Clin. Anat. 31:788-796, 2018. © 2018 Wiley Periodicals, Inc.

[Blood vessels and nerves surrounding the seminal vesicles: A clinical anatomic study].

OBJECTIVE: To investigate the precise locations of the blood vessels and nerves surrounding the seminal vesicles (SV) in men and provide some anatomical evidence for SV-related minimally invasive surgery. METHODS: We observed the courses and distribution of the blood vessels and nerves surrounding SVs and obtained the data for positioning the SV neuroplexes in 20 male pelvises. RESULTS: One branch of the neuroplexes was distributed to the SVs bilaterally with the neurovascular bundles, (2.85 ± 0.18) cm from the median sulcus of the prostate (MSP), while another branch ran through the Denonvillier fascia behind the SV, (0.81 ± 0.06) cm from the MSP. The arterial SVs (ASV) originated from the inferior vesical artery and fell into 4 types, 55% going directly to the SVs as one branch, 15% running between the SV and the ampulla of the deferent duct as another branch, 25% downward as 2 branches to the SV and between the SV and the ampulla of the deferent duct respectively, and 5% as the other ASVs. The shortest distance from the ASV through the prostatic neuroplexus to the posterior SV was (1.08 ± 0.09) cm. CONCLUSION: In SV resection, neuroplexus injury can be reduced with a bilateral distance of < 2.85 cm and a posterior distance of < 0.81 cm from the MSP, and so can bleeding by vascular ligation between the SV and the ampulla of the deferent duct.

Anatomical study of pelvic nerves in relation to seminal vesicles, prostate and urethral sphincter: immunohistochemical staining, computerized planimetry and 3-dimensional reconstruction.

PURPOSE: Studies of male pelvic neuroanatomy are mandatory to improve functional outcome after radical prostatectomy. We performed a topographical investigation of nerves on the course from the seminal vesicles along the prostate toward the striated urethral sphincter. MATERIALS AND METHODS: Serial whole mount sections (1 mm intervals) of pelvic blocks of human adult male autopsy cadavers were investigated after immunohistochemical nerve staining. Computerized nerve quantification and planimetry of the total nerve surface area were performed within defined regions (ventral, ventrolateral, dorsolateral and dorsal) at the levels of the seminal vesicles and prostate, and at the striated urethral sphincter. The distance between the seminal vesicles and the nerves was measured. For improved topographical understanding 3-dimensional reconstructions were created. Differences between 3 independent variables were tested with the nonparametric Kruskal-Wallis test. RESULTS: We studied a total of 969 whole mount sections of 5 cadavers. Nerves were arranged in a vertical plate lateral to the seminal vesicles. Mean ± SD distance to the seminal vesicles was 1.68 ± 0.84, 1.50 ± 0.12 and 1.76 ± 0.37 mm at the tip, middle and base, respectively. Periprostatic nerves were mainly found dorsolaterally. At the striated urethral sphincter 38.9% of nerves had shifted to the dorsal region. The total nerve surface area decreased significantly from the seminal vesicle tip (50.2 mm(2)) to the striated urethral sphincter level (13.3 mm(2)) (p = 0.0004). CONCLUSIONS: Our findings underline that during nerve sparing prostatectomy nerve damage might occur during mobilization of the entire seminal vesicles, apical dissection and posterior reconstruction of the rhabdosphincter. Nerve planimetry revealed that 75% of the nerves from the seminal vesicles do not reach the striated urethral sphincter level and seem to innervate structures other than the corpora cavernosa.

The role of sympathetic and parasympathetic nerve systems on the smooth muscle of rat seminal vesicles - experimental results and speculation for physiological implication on ejaculation.

Ejaculation is a process involving sympathetic and parasympathetic effects during different stages - emission and ejection. Some conditions of ejaculation dysfunction are associated with autonomic nerves. However, the exact effects of autonomic nerves on ejaculation are not well defined. Autonomic agonists induce different recorded trace patterns of seminal vesicular contraction. The different traces contain different components of phasic and tonic contraction, which may have physiological implications. In this study, we examined isolated rat seminal vesicle (SV) contraction by phenylephrine (PE), acetylcholine, and their respective antagonists and then speculated upon physiological roles of sympathetic and parasympathetic nerves on SV during ejaculation. We found that PE and Ach both achieved good contraction of rat SV. Compared to α1b for sympathetic and M1, M2 for parasympathetic receptors, α1a and M3 are the relatively dominant subtypes on rat SV. Adrenergic and cholinergic agonists cause different trace patterns of SV contraction. We speculated that the sympathetic effect is dominant during emission to squeeze seminal fluid out and that the parasympathetic effect is dominant during ejection to provide an anti-reflux effect on the ejaculatory duct.

Evidence that adrenergic and cholinergic but not capsaicin-sensitive nerves are involved in the nerve-mediated contraction of the guinea pig seminal vesicle.

BACKGROUND/AIMS: The neurotransmitters participating in the nerve-mediated contraction of the guinea pig seminal vesicle (GPSV) have not been firmly established. There is debate as to the mediating role of norepinephrine and acetylcholine. METHODS: We have used longitudinally and circularly oriented strips of GPSV and activated their intramural nerves by electrical field stimulation (5 and 10 Hz for 30 s). RESULTS: Contractile responses to stimulation were enhanced by a cholinesterase inhibitor and reduced by the adrenergic α-receptor antagonist phentolamine (2.5 µmol/l). Atropine (1 µmol/l) significantly reduced responses in longitudinal preparations; a less consistent inhibition was found in circular preparations. The sensory neuron stimulant and blocker capsaicin was without effect. CONCLUSIONS: It is concluded that adrenergic nerves and also acetylcholine mediate the contractile response of the GPSV.

Anatomical description of the periprostatic nerves in the male rhesus monkey (Macaca mulatta).

OBJECTIVES: Recent publications have revealed a variable course of the periprostatic nerves in humans. It is unclear to what extent nerves outside the dorsolateral region of the prostate are involved in the physiology of erectile function. As functional studies in humans are limited by ethical aspects investigations in animal models could provide further insight. The intention of this study was to give a detailed description of the topographical anatomy of autonomic nerves along the seminal vesicles and the prostate in male rhesus monkeys (Macaca mulatta) to investigate its suitability as an animal model for future physiological studies. METHODS: Wholemount serial sections of pelvic organ blocks of ten male rhesus monkeys were investigated. Autonomic nerves were stained with an antibody against S100. RESULTS: Autonomic nerves were dispersed along the dorsolateral to the ventrolateral aspect of the capsule of the prostate within a layer of connective tissue. There was no accumulation of vessels and nerves in the dorsolateral position of the prostate. The prostate is located dorsally to the urethra and does not encircle it. No adjacent nerves were found in the cranial two-thirds of the seminal vesicles. CONCLUSIONS: The male rhesus monkey is limited suitable as an animal model for studies on the periprostatic nerves provided the following differences to humans are considered: the special topography of the prostate, the nerve course along the seminal vesicles and the missing nerve accumulation dorsolaterally to the prostate.

Parasympathetic influence plays an independent and significant role in inducing the contraction of the seminal vesicle of the rat.

OBJECTIVES: The role of the parasympathetic pathway in seminal vesicle (SV) contraction has not been well described. The purpose of this study was to study parasympathetic effects, the dominant muscarinic receptors subtype(s), and nitric oxide (NO) effects for SV contraction. METHODS: In vivo, SV pressure of mature male Wistar rats were recorded after electric stimulation (ES) of each pelvic nerve (PN; parasympathetic pathway) alone; bilateral PNs simultaneously, the L6 and S1 branches of the left PN; the left PN after ablation of sympathetic influence; the lesser splanchnic nerve (LSN) after ablation of parasympathetic influence; and the LSN after pretreatment of 4 muscarinic receptor antagonists or a NO donor-3-Morpholinosydnonimine (SIN-1). RESULTS: ES to the left PN caused frequency-dependent SV contraction, with similar results after ES to the right PN and bilateral PNS. ES to the L6 branch of the left PN caused significantly greater SV response than to the S1 branch. Ablation of sympathetic influence did not affect SV response to parasympathetic stimulation and vice versa. The inhibitory effects of 4-DAMP (M3 antagonist) and atropine (nonselective muscarinic antagonist) on SV response to ES were similar and significantly greater than those of pirenzepine (M1 antagonist) and methoctramine (M2 antagonist). Pretreatment of SIN-1 partially suppressed the SV response of ES to left PN. CONCLUSIONS: ES via the parasympathetic pathway independently induces contraction of rat SV; NO partially suppresses the SV pressure response to parasympathetic ES.

Neuropeptides in the rat corpus cavernosum and seminal vesicle: effects of age and two types of diabetes.

AIMS: To observe the development of neuropathic changes in two types of experimental diabetes using changes in concentrations of NPY, CGRP and amines in the corpora cavernosa and seminal vesicles. Type I diabetes was studied in Wistar rats after 12 and 16 weeks of STZ-induced hyperglycaemia, and Type II diabetes was studied in prediabetic GK rats aged 52 weeks. Both were compared with age-matched normal Wistar rats. METHODS: NPY and CGRP were estimated using radioimmunoassay, and amines using HPLC. RESULTS: There were significant changes in [CGRP] in the normal corpus cavernosum and in [NPY] in the normal seminal vesicle with age. STZ-diabetes, induced at 10 weeks of age, resulted in significant elevation of [NPY] and [CGRP] in the corpora cavernosa and seminal vesicles after 12 and 16 weeks of hyperglycaemia, relative to age-matched control rats. The GK rats were intolerant of glucose at 52 weeks of age, but did not have raised fasting blood glucose levels. [NPY], [CGRP] and [noradrenaline] in corpora cavernosa were significantly increased in the prediabetic GK animals relative to age-matched Wistar control rats. The seminal vesicles of GK rats showed a significant increase in [NPY], a non-significant increase in [CGRP], and a fall in [noradrenaline] relative to the age-matched Wistar controls. CONCLUSIONS: The results indicate increased levels of NPY and noradrenaline in autonomic nerves, and of CGRP in sensory nerves, innervating the corpus cavernosum in Type I and in prediabetic Type II GK rats.

Noradrenergic and cholinergic innervation of the accessory sexual glands in male sheep.

Immunohistochemistry was applied to determine the distribution patterns of nerve fibres containing tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DbetaH), neuropeptide Y (NPY), vasoactive intestinal peptide (VIP) and vesicular acetylcholine transporter (VAChT) in the prostate, seminal vesicle (SV) and bulbourethral glands (BU) of male sheep. In all organs studied, cholinergic innervation was more developed than noradrenergic innervation. Numerous VAChT-immunoreactive (IR) nerve fibres were found in the muscular layer and mucosa of the SV and BU as well as in the prostate. A similar abundance of noradrenergic nerve fibres (showing immunoreactivity both to TH and DbetaH) was also found in both layers of the SV and BU (but not in the prostate). In the prostate a moderate density of VIP-IR nerve fibres was present but only very scarce NPY-IR nerve fibres were shown. All the studied accessory sexual glands (ASG) of male sheep contained VIP-IR nerve fibres in a similar frequency. Double immunohistochemistry revealed that the vast majority of noradrenergic nerve fibres also contained NPY. None of the noradrenergic nerve fibres showed the presence of VAChT or VIP. The possible functional significance of these findings is discussed.

Effects of castration on the expression of brain-derived neurotrophic factor (BDNF) in the vas deferens and male accessory genital glands of the rat.

Brain-derived neurotrophic factor (BDNF) is a growth factor belonging to the family of neurotrophins. Although neurotrophins in the male genital organs have been well documented, their role in the biology of these organs is far from clear. In particular, little is known about the influence of sex hormones on neurotrophin expression. In the present study, using immunohistochemistry and enzyme-linked immunosorbent assay (ELISA), we investigated the distribution and tissue concentration of BDNF in the vas deferens and accessory male genital glands in normal and castrated rats. The expression of BDNF mRNA was also investigated. In normal rats, BDNF immunoreactivity was localized in the musculature of the vas deferens and vesicular gland and in the fibromuscular stromal cells of the prostate. In the ventral prostatic lobes, BDNF immunoreactivity was localized in basal, secretory and neuroendocrine epithelial cells. Innervating ganglia and nerves were immunoreactive in all the examined tracts. After castration, BDNF immunoreactivity increased in the musculature of the vesicular gland and in the fibromuscular stromal cells of both dorsal and ventral prostatic lobes. BDNF immunoreactivity also increased in the nerves. ELISA and reverse transcription/real-time polymerase chain reaction confirmed the findings of the immunohistochemical study. In the accessory glands, castration induced an increase of both BDNF tissue concentration and mRNA expression. These results suggest that BDNF is expressed in the internal male genital organs of the rat and that its expression is downregulated by androgen hormones. We hypothesize that the observed BDNF increases are related to the castration-induced regression of the sympathetic nerves.

Puberty installation and adrenergic response of seminal vesicle from rats exposed prenatally to hydrocortisone.

We investigated the effects of hydrocortisone during the prenatal period and its repercussion on puberty installation and adrenergic response of seminal vesicle in adult rats. The efficacy of the hydrocortisone treatment in reducing adrenal wet weight immediately after delivery in both the treated mothers and respective pups at birth may indicate impairment of the hypothalamus--pituitary--adrenal axis. This parameter was unchanged in the adult phase of these descendants, suggesting recuperation of this axis. In addition, the treatment with hydrocortisone delayed the age of puberty installation, probably by absence of both physiologic production and liberation of luteinizing hormone and testosterone. Despite the significant reduction in testosterone level as well as of wet weights of both vas deferens and testis in the adult phase, no difference was observed in the sensitivity of the seminal vesicle to the studied sympathetic agonist. However, the observed reduction in contractile response of the seminal vesicle may be a consequence of contractile-system damage in this organ. It is possible that this alteration may cause a reduction in the amount of vesicular secretion so important in the process of ejaculation. In conclusion, these results suggest that administration of hydrocortisone in late prenatal life did not influence the hypothalamus--pituitary--adrenal axis in adult life, although it altered the hypothalamus--pituitary--gonadal axis, and reduced testosterone production starting at puberty, as a consequence of an incomplete masculinization of the hypothalamus plus a reduction in the contractile response of the seminal vesicle.

Distribution of calcitonin gene-related peptide (CGRP), substance P (SP) and galanin (GAL) immunoreactive nerve fibers in the seminal vesicle and prostate of the male sheep.

Double immunohistochemistry was used to determine the occurrence and distribution pattern of nerve fibres immunoreactive to calcitonin gene-related peptide (CGRP), substance P (SP) and galanin (GAL) in seminal vesicles and prostate of the male sheep. Numerous CGRP- and SP-immunoreactive (IR) nerve fibres were found in the mucosal layer and smooth musculature of the seminal vesicles and prostate. In both glands nerve terminals immunoreactive to CGRP were more numerous than SP-IR ones. The majority of CGRP-IR nerve fibers showed colocalization of this peptide and SP. In both layers of the seminal vesicle and prostate, rare nerve terminals immunoreactive to GAL were also found. Immunoreactivity to SP was also found in all GAL-IR nerve fibers. The presence of numerous CGRP- and SP-IR nerve fibers in the seminal vesicle and prostate of the male sheep suggests that these neuropeptides may be involved in the sensory transmission and/or control of smooth muscle contractility. On the other hand, a relatively low number of GAL-IR nerve fibers of the seminal vesicle and prostate suggest that this peptide may act as an anti-nociceptive agent. It cannot be excluded that, in the seminal vesicle, GAL may also be involved in the control of the smooth muscle fiber activity. The possible role of CGRP, SP and GAL in the regulation of functions of the accessory sexual glands needs to be determined in further physiological studies.

An operative and anatomic study to help in nerve sparing during laparoscopic and robotic radical prostatectomy.

OBJECTIVE: To provide a detailed description of the steps involved in a laparoscopic radical prostatectomy in relation to the complex neurovascular anatomy of the male pelvis. AIM AND HYPOTHESIS: We aimed at delineating the neurovascular anatomy to assist in nerve preservation during laparoscopic and robotic radical prostatectomies. METHODS: A team of urologists and an anatomist performed anatomic dissections of 12 male cadavers using a combination of laparoscopic equipment, magnification, and open surgical dissection. Each step involved in laparoscopic prostatectomy was reviewed in relation to the possible impact the step could have on the neurovascular bundles. RESULTS: Dissections were performed systematically to mimic various steps of laparoscopic and robotic prostatectomy. The neurovascular bundles were identified and correlated with video images of actual surgery. This enabled us to construct computer simulations and show the actual nerves on the operative pictures. We specially unraveled the relationship between neurovascular bundles and lateral pelvic and Denonvillier's fascias, both of which enclose and hide these important structures. The course of the bundles was traced from its origin at pelvic plexus to its distal course along the urethra. We also showed the important relationship between pelvic plexus ganglions and seminal vesicles to illustrate the vulnerability of these nerves to thermal, electrical and/or crush injury during seminal vesicle and prostatic pedicle dissections. The importance of additional fine neural plexus along the posterior and antero-lateral surface of the prostate was shown by both gross anatomical and microscopic images. The distal precarious location of the bundles was illustrated by dissections showing anteriorly lifted prostate.These anatomico-operative correlations have not been published for laparoscopic and robotic prostatectomies, which differ significantly in its visual angles, magnifications and sometimes three-dimensional (3D) visualization from its open counter part. CONCLUSION: Laparoscopic and robotic radical prostatectomy provides exposure and visualization of male pelvis not previously appreciated. It is only through a careful reexamination of the anatomy of the male pelvis, in the context of this new procedure, that the improvements in visualization and exposure benefit the surgeon. Our work provides a detailed map relating to operative steps to aid the surgeon in the performance of a nerve sparing robotic and laparoscopic radical prostatectomy.

Mechanisms of excitatory transmission in circular smooth muscles of the guinea pig seminal vesicle.

PURPOSE: Cellular mechanisms of excitatory neuromuscular transmission in circular smooth muscles of the seminal vesicle were investigated. MATERIALS AND METHODS: Circular smooth muscles of the seminal vesicle of the guinea pig were isolated. Changes in membrane potential produced by transmural nerve stimulation were recorded using intracellular microelectrode techniques. Changes in the intracellular Ca ion concentration induced by transmural nerve stimulation were measured in preparations loaded with Ca indicator fura-PE3. Responses produced by bath applied norepinephrine and alpha,beta-methylene adenosine triphosphate (ATP) were also examined. RESULTS: Transmural nerve stimulation evoked excitatory junction potentials that triggered action potentials and also caused transient increases in [Ca2+] (Ca transients). Nifedipine abolished action potentials, leaving underlying excitatory junction potentials unchanged, and reduced the amplitude of Ca transients. Excitatory junction potentials were blocked by alpha,beta-methylene ATP or guanethidine but not by phentolamine. A train of transmural nerve stimulation evoked oscillatory changes in membrane potential and [Ca2+], which were abolished by phentolamine or inhibited by nifedipine. Nifedipine insensitive components were abolished by cyclopiazonic acid. Norepinephrine depolarized the membrane and elicited oscillatory potentials with an associated elevation in [Ca2+]. These responses were inhibited by nifedipine and abolished by additional application of cyclopiazonic acid. Transient depolarization with an associated increase in [Ca2+] was elicited by alpha,beta-methylene ATP and [Ca2+] responses but no potential changes were inhibited by nifedipine. CONCLUSIONS: Circular smooth muscles of the guinea pig seminal vesicle receive a projection of sympathetic nerves that release norepinephrine to initiate slow depolarization through the activation of alpha-adrenoceptors. These nerves also release ATP to elicit excitatory junction potentials. Neurally released norepinephrine and ATP are increased [Ca2+] by the influx of Ca2+ through L-type Ca2+ channels and also by the release of Ca2+ from internal stores.

Smooth muscle does not have a common P2x receptor phenotype: expression, ontogeny and function of P2x1 receptors in mouse ileum, bladder and reproductive systems.

The distribution, ontogeny and role of P2x1 receptors were examined in the smooth muscle of the mouse intestine, bladder, and male and female reproductive tracts using P2x1 receptor subtype selective antibodies and contraction studies. P2x1 receptor immunoreactivity showed a heterogeneous distribution in smooth muscle with high levels expressed in adult vas deferens, bladder, arteries and male reproductive organs. In contrast, P2x1, receptors were below the level of detection in the smooth muscle of the ileum and female reproductive tract. P2x1 receptor immunoreactivity was detected at adult levels from birth in the bladder. However, in the vas deferens, immunoreactivity was only detected from 10 days after birth and reached adult levels by approximately 1 month old. A similar pattern of expression was seen in the vesicular seminalis, epididymis, gland of the vas deferens and coagulating gland. Sensitivity to the P2x1 receptor agonist alpha,beta-methylene ATP (alpha,beta-meATP) and P2x1 receptor-deficient mice were used in functional studies to determine the role of P2x1 receptors in the control of smooth muscle. alpha,beta-meATP (100 microM) failed to evoke contractions of the epididymis, or seminal vesicle and P2x1 receptors did not contribute to the control of uterine smooth muscle. In the ileum, alpha,beta-meATP (100 microM) evoked a transient relaxation followed by a contraction. These responses were abolished by the P2 receptor antagonist iso-pyridoxalphosphate-6-azophenyl-2'-5'-disulphonate (iso-PPADS) (30 microM). Relaxant responses were abolished by the adenosine A1 receptor antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) (1 microM). Contractile responses were reduced by > 80% in the ileum from P2x1 receptor-deficient mice. alpha,beta-meATP-evoked contractions were reduced by approximately 35% by TTX (1 microM) and were unaffected by atropine (10 microM). These studies indicate that P2x1 receptors are not expressed throughout all smooth muscles and that their expression is developmentally regulated. In addition, they provide evidence to suggest that P2x1 receptors are present on pre-synaptic nerve terminals in the enteric nervous system.

Investigación anatómica de los plexos autónomos génito-vesicales; su importancia en la cirugía del cáncer del recto / Anatomic investigation of autonomous urogenital innervations: importance in rectum cancer surgery

Antecedentes: En la cirugía del cáncer de recto, próstata y útero es necesario conocer la inervación autónoma urogenital a fin de realizar una resección radical con preservación de dicha inervación. Objetivo: Determinar los jalones apropiados para la investigación del plexo presacro, nervios y plexo hipogástrico inferior, erectores en su origen y trayecto que siguen hacia los órganos genitourinarios. Lugar de aplicación: Hospital Público. Diseño: Trabajo de investigación anatómico. Población: 7 especímenes, 5 masculinos y 2 femeninos, se disecaron en total 10 plexos. Método: a) investigación del plexo presacro, nervios y plexo hipogástrico inferior y erectores; b) resección en bloque con un segmento de órganos vecinos; c) estaqueada la pieza es sumergida en formol y Complucad; d) disección de los plexos, fotografías y esquemas; e) biopsias de segmentos de dichos plexos. Resultados: Los erectores dependientes del 3§ y 4§ nervio espinal estuvieron presentes en todas las piezas. Los originados en S3 eran de mayor envergadura y alcanzaban el plexo hipogástrico inferior, los originados en S4 eran finos y discurrían directamente hacia el pene, 1 caso se integraba al plexo hipogástrico inferior; en 2 especímenes hubo anastomosis entre ambos plexos hipogástricos. Conclusiones: en todos los especímenes estaban presentes los nervios erectores. Los de mayor envergadura eran los del 3§ espinal. Los del 4§ espinal discurrían directamente hacia el pene. Las raíces espinales 2§, 3§ y 4§ y el músculo piramidal son jalones importantes en la localización de los erectores