Testosterone has potent, selective effects on the morphology of pelvic autonomic neurons which control the bladder, lower bowel and internal reproductive organs of the male rat

Differential effects of exercise and hormone treatment on spinal cord injury-induced changes in micturition and morphology of external urethral sphincter motoneurons

Background

Spinal cord injury (SCI) results in lesions that destroy tissue and spinal tracts, leading to deficits in locomotor and autonomic function. We have previously shown that after SCI, surviving motoneurons innervating hindlimb muscles exhibit extensive dendritic atrophy, which can be attenuated by treadmill training or treatment with gonadal hormones post-injury. We have also shown that following SCI, both exercise and treatment with gonadal hormones improve urinary function. Animals exercised with forced running wheel training show improved urinary function as measured by bladder cystometry and sphincter electromyography, and treatment with gonadal hormones improves voiding patterns as measured by metabolic cage testing.

Objective

The objective of the current study was to examine the potential protective effects of exercise or hormone treatment on the structure and function of motoneurons innervating the external urethral sphincter (EUS) after contusive SCI.

Methods

Gonadally intact young adult male rats received either a sham or a thoracic contusion injury. Immediately after injury, one cohort of animals was implanted with subcutaneous Silastic capsules filled with estradiol (E) and dihydrotestosterone (D) or left blank; continuous hormone treatment occurred for 4 weeks post-injury. A separate cohort of SCI-animals received either 12 weeks of forced wheel running exercise or no exercise treatment starting two weeks after injury. At the end of treatment, urinary void volume was measured using metabolic cages and EUS motoneurons were labeled with cholera toxin-conjugated horseradish peroxidase, allowing for assessment of dendritic morphology in three dimensions.

Results

Locomotor performance was improved in exercised animals after SCI. Void volumes increased after SCI in all animals; void volume was unaffected by treatment with exercise, but was dramatically improved by treatment with E + D. Similar to what we have previously reported for hindlimb motoneurons after SCI, dendritic length of EUS motoneurons was significantly decreased after SCI compared to sham animals. Exercise did not reverse injury-induced atrophy, however E + D treatment significantly protected dendritic length.

Conclusions

These results suggest that some aspects of urinary dysfunction after SCI can be improved through treatment with gonadal hormones, potentially through their effects on EUS motoneurons. Moreover, a more comprehensive treatment regime that addresses multiple SCI-induced sequelae, i.e., locomotor and voiding deficits, would include both hormones and exercise.

Sex steroid metabolism and action in colon health and disease

The colon is the largest hormonally active tissue in the human body. It has been known for over a hundred years that various hormones and bioactive peptides play important roles in colon function. More recently there is a growing interest in the role the sex steroids, oestrogens and androgens, may play in both normal colon physiology and colon pathophysiology. In this review, we examine the potential role oestrogens and androgens play in the colon. The metabolism and subsequent action of sex steroids in colonic tissue is discussed and how these hormones impact colon motility is investigated. Furthermore, we also determine how oestrogens and androgens influence colorectal cancer incidence and development and highlight potential new therapeutic targets for this malignancy. This review also examines how sex steroids potentially impact the severity and progression of other colon disease, such as diverticulitis, irritable bowel syndrome, and polyp formation.

The androgen receptor in bladder cancer

Bladder cancer is the ninth most common cancer worldwide with a striking sex-based difference in incidence. Emerging evidence indicates that the androgen receptor (AR) might promote the development, progression and recurrence of bladder cancer, contributing to the observed sex differences. Targeting androgen-AR signalling has promise as potential therapy for bladder cancer and helps to suppress progression of this disease. In addition, the identification of a new membrane AR and AR-regulated non-coding RNAs has important implications for bladder cancer treatment. The success of human clinical trials of targeted-AR therapies will help in the development of improved treatments for patients with bladder cancer.

Potential Effect of the Circadian Clock on Erectile Dysfunction

The circadian rhythm is an internal timing system, which is generated by circadian clock genes. Because the circadian rhythm regulates numerous cellular, behavioral, and physiological processes, organisms have evolved with intrinsic biological rhythms to adapt the daily environmental changes. A variety of pathological events occur at specific times, while disturbed rhythms can lead to metabolic syndrome, vascular dysfunction, inflammatory disorders, and cancer. Therefore, the circadian clock is considered closely related to various diseases. Recently, accumulated data have shown that the penis is regulated by the circadian clock, while erectile function is impaired by an altered sleep-wake cycle. The circadian rhythm appears to be a novel therapeutic target for preventing and managing erectile dysfunction (ED), although research is still progressing. In this review, we briefly summarize the superficial interactions between the circadian clock and erectile function, while focusing on how disturbed rhythms contribute to risk factors of ED. These risk factors include NO/cGMP pathway, atherosclerosis, diabetes mellitus, lipid abnormalities, testosterone deficiency, as well as dysfunction of endothelial and smooth muscle cells. On the basis of recent findings, we discuss the potential role of the circadian clock for future therapeutic strategies on ED, although further relevant research needs to be performed.

Ex vivo Akt inhibition reverses castration induced internal pudendal artery and penile endothelial dysfunction

AIMS

Androgen deprivation therapy is a common prostate cancer treatment which causes men to have castrate levels of testosterone. Unfortunately, most testosterone deficient patients will suffer severe erectile dysfunction (ED) and have no effective ED treatment options. Testosterone deficiency causes endothelial dysfunction and impairs penile vasodilation necessary to maintain an erection. Recent evidence demonstrates testosterone activates androgen receptors (AR) and generates nitric oxide (NO) through the Akt-endothelial NO synthase (eNOS) pathway; however, it remains unknown how castration impacts this signaling pathway.

MATERIALS AND METHODS

In this study, we used a surgically castrated rat model to determine how castration impacts ex vivo internal pudendal artery (IPA) and penile relaxation through the Akt-eNOS pathway.

KEY FINDINGS

Unlike systemic vasculature, castration causes significant IPA and penis endothelial dysfunction associated with a 50% AR reduction. Though testosterone and acetylcholine (ACh) both phosphorylate Akt and eNOS, castration did not affect testosterone-mediated IPA and penile Akt or eNOS phosphorylation. Surprisingly, castration increases ACh-mediated Akt and eNOS phosphorylation but reduces the eNOS dimer to monomer ratio. Akt inhibition using 10DEBC preserves IPA eNOS dimers. Functionally, 10DEBC reverses castration induced ex vivo IPA and penile endothelial dysfunction.

SIGNIFICANCE

These data demonstrate how castration uncouples eNOS and provide a novel strategy for improving endothelial-dependent relaxation necessary for an erection. Further studies are needed to determine if Akt inhibition may treat or even prevent ED in testosterone deficient prostate cancer survivors.

The influence of castration on intramural neurons of the urinary bladder trigone in male pigs

The present study investigated the influence of castration performed at neonatal age on neuronal elements in the intramural ganglia of the urinary bladder trigone (UBT) in male pigs using double-labeling immunohistochemistry. The ganglia were examined in intact (IP) 7-day-old (castration day) pigs, and at 3 and 6 months after surgery. In IP and control (3- and 6-month-old noncastrated pigs) groups, virtually, all neurons were adrenergic (68%) or cholinergic (32%) in nature. Many of them (32%, 51%, and 81%, respectively; 56%, 75%, and 85% adrenergic; and 32%, 52%, and 65% cholinergic, respectively) stained for the androgen receptor (AR), and only a small number of nerve cells were caspase-3 (CASP-3)-positive. In 3- and 6-month-old castrated pigs, an excessive loss (87.6% and 87.5%, respectively) of neurons and intraganglionic nerve fibers was observed. The majority of the surviving adrenergic (61% and 72%, respectively) and many cholinergic (41% and 31%, respectively) neurons expressed CASP-3 and were also AR-positive (61% and 66%, and 40% and 36%, respectively). This study revealed for the first time the excessive loss of intramural UBT neurons following castration, which could have resulted from apoptosis induced by androgen deprivation.

The Effect of Castration on Peripheral Autonomic Neurons Supplying Mammalian Male Genitourinary System

This review paper deals with the influence of androgens (testosterone) on pelvic autonomic pathways in male mammals. The vast majority of the relevant information has been gained in experiments involving castration (testosterone deprivation) performed in male rats, and recently, in male pigs. In both species, testosterone significantly affects the biology of the pathway components, including the pelvic neurons. However, there are great differences between rats and pigs in this respect. The most significant alteration is that testosterone deprivation accomplished a few days after birth results some months later in the excessive loss (approximately 90%) of pelvic and urinary bladder trigone intramural neurons in the male pig, while no changes in the number of pelvic neurons are observed in male rats (rats do not have the intramural ganglia). In the castrated pigs, much greater numbers of pelvic neurons than in the non-castrated animals express CGRP, GAL, VIP (peptides known to have neuroprotective properties), and caspase 3, suggesting that neurons die due to apoptosis triggered by androgen deprivation. In contrast, only some morpho-electrophysiological changes affecting neurons following castration are found in male rats. Certain clinicopathological consequences of testosterone deprivation for the functioning of urogenital organs are also discussed.

Quantification of neural and hormonal receptors at the prostate of long-term sexual behaving male rats after lesion of pelvic and hypogastric nerves

Prostate function is regulated by androgens and a neural control via the pelvic and hypogastric nerves. As such, this sexual gland contains receptors for acetylcholine and noradrenaline, although it is unknown whether the expression of these receptors is affected by sexual behavior and even less by denervation of the gland. Thus, the purpose of this work was to evaluate the effect of repeated sexual behavior on the expression of noradrenaline, acetylcholine, and androgen receptors at the prostate, and how they are affected by denervation. To achieve this, we used sexually experienced males denervated at the pelvic or hypogastric nerves, or both. The messenger (mRNA) and protein for androgen, noradrenergic, and cholinergic receptors were evaluated. The weight of the gland and the levels of serum testosterone were also measured. We found that: (1) sexual behavior was not affected by denervation; (2) blood testosterone levels increased due to sexual behavior but such increase is prevented by denervation; (3) the weight of the ventral prostate increased with sexual behavior but was not affected by denervation; (4) AR messenger levels increased with sexual behavior but were not altered by denervation; (5) the messenger for noradrenergic and cholinergic receptors decreased after denervation, and those for muscarinic receptors increased, and (6) only AR protein decreased after denervation of both nerves, while those for other receptors remained unchanged. In summary, we show that the three receptors have different regulatory mechanisms, and that only androgen receptors are regulated by both autonomic systems.

Impact of sex, androgens, and prostate size on C57BL/6J mouse urinary physiology: functional assessment

Laboratory mice are used to identify causes of urinary dysfunction including prostate-related mechanisms of lower urinary tract symptoms. Effective use of mice for this purpose requires a clear understanding of molecular, cellular, anatomic, and endocrine contributions to voiding function. Whether the prostate influences baseline voiding function has not been specifically evaluated, in part because most methods that alter prostate mass also change circulating testosterone concentrations. We performed void spot assay and cystometry to establish a multiparameter "baseline" of voiding function in intact male and female 9-wk-old (adult) C57BL/6J mice. We then compared voiding function in intact male mice to that of castrated male mice, male (and female) mice treated with the steroid 5α-reductase inhibitor finasteride, or male mice harboring alleles (Pbsn4^cre/+; R26R^Dta/+) that significantly reduce prostate lobe mass by depleting prostatic luminal epithelial cells. We evaluated aging-related changes in male urinary voiding. We also treated intact male, castrate male, and female mice with exogenous testosterone to determine the influence of androgen on voiding function. The three methods used to reduce prostate mass (castration, finasteride, and Pbsn4^cre/+; R26R^Dta/+) changed voiding function from baseline but in a nonuniform manner. Castration feminized some aspects of male urinary physiology (making them more like intact female mice) while exogenous testosterone masculinized some aspects of female urinary physiology (making them more like intact male mice). Our results provide evidence that circulating testosterone is responsible in part for baseline sex differences in C57BL/6J mouse voiding function while prostate lobe mass in young, healthy adult mice has a lesser influence.

Somatic and psychological triggers for bladder storage symptoms among men and women

INTRODUCTION AND HYPOTHESIS

To determine the prevalence of somatic and psychological triggers for bladder storage symptoms among men and women who have not been diagnosed with overactive bladder (OAB) and to determine their impact on individuals' quality of life (QoL).

METHODS

Randomly selected male and female volunteers were screened for the presence of bladder storage symptoms and their impact on their QoL using the UDI-6 and IIQ-7 questionnaires. They were also asked about somatic and psychological triggers for these symptoms using the validated SOPSETO questionnaire. Individuals who had previously been diagnosed with or treated for OAB, prostatic hypertrophy, neurological disease or cancer were excluded.

RESULTS

Sixty-six women and 40 men were included. There was a significantly higher prevalence of urinary urgency (41% vs. 19%, p = 0.021), urge urinary incontinence (22% vs. 0%, p = 0.002) and stress urinary incontinence (30% vs. 3%, p = 0.001) among women than men. Total UDI-6 (17± 15 vs. 9± 8, p = 0.04) and IIQ-7 (21± 10 vs. 15± 4, p = 0.02) scores were also higher among women than men. Of the total 34 triggers evaluated, 18 were ranked significantly higher among women than among men. There was a good correlation between the SOPSETO and the UDI-6 and IIQ-7 scores primarily in women (r = 0.46, p < 0.0001; r = 0.69, p < 0.0001) but also in men (r = 0.44, p = 0.009; r = 0.39, p = 0.02).

CONCLUSIONS

Women who have not been diagnosed with OAB report bladder storage symptoms more frequently than men. Somatic and psychological triggers are more likely to stimulate these symptoms in women than in men and might add burden to their QoL.

Sex differences in lower urinary tract biology and physiology

Females and males differ significantly in gross anatomy and physiology of the lower urinary tract, and these differences are commonly discussed in the medical and scientific literature. However, less attention is dedicated to investigating the varied development, function, and biology between females and males on a cellular level. Recognizing that cell biology is not uniform, especially in the lower urinary tract of females and males, is crucial for providing context and relevance for diverse fields of biomedical investigation. This review serves to characterize the current understanding of biological sex differences between female and male lower urinary tracts, while identifying areas for future research. First, the differences in overall cell populations are discussed in the detrusor smooth muscle, urothelium, and trigone. Second, the urethra is discussed, including anatomic discussions of the female and male urethra followed by discussions of cellular differences in the urothelial and muscular layers. The pelvic floor is then reviewed, followed by an examination of the sex differences in hormonal regulation, the urinary tract microbiome, and the reticuloendothelial system. Understanding the complex and dynamic development, anatomy, and physiology of the lower urinary tract should be contextualized by the sex differences described in this review.

Impact of Testosterone Deficiency and Testosterone Therapy on Lower Urinary Tract Symptoms in Men with Metabolic Syndrome

Lower urinary tract function is modulated by neural, vascular and urethral and bladder structural elements. The pathophysiological mechanisms of lower urinary tract symptoms (LUTS) encompass prostate enlargement, alterations in urethra histological structure bladder fibrosis and alterations in pelvic neuronal and vascular networks, The complex pathophysiological relationship between testosterone (T) deficiency (TD) and the constellations LUTS, and metabolic dysfunction manifested in the metabolic syndrome (Met S) remains poorly understood. TD has emerged as one the potential targets by which Met S may contribute to the onset and development as well as worsening of LUTS. Because it has been recognized that treatment of men with Met S with T therapy ameliorates Met S components, it is postulated that T therapy may represent a therapeutic target in improving LUTS. Furthermore, the effect of TD on the prostate remains unclear, and often debatable. It is believed that T exclusively promotes prostate growth, however recent evidence has strongly contradicted this belief. The true relationship between benign prostatic hyperplasia, TD, and LUTS remains elusive and further research will be required to clarify the role of T in both benign prostatic hypertrophy (BPH) and LUTS as a whole. Although there is conflicting evidence about the benefits of T therapy in men with BPH and LUTS, the current body of literature supports the safety of using this therapy in men with enlarged prostate. As the population afflicted with obesity epidemic continues to age, the number of men suffering from Met S and LUTS together is expected to increase.

Protective Effects of Estradiol and Dihydrotestosterone following Spinal Cord Injury

Spinal cord injury (SCI) results in lesions that destroy tissue and disrupt spinal tracts, producing deficits in locomotor and autonomic function. We previously demonstrated that motoneurons and the muscles they innervate show pronounced atrophy after SCI, and these changes are prevented by treatment with testosterone. Here, we assessed whether the testosterone active metabolites estradiol and dihydrotestosterone have similar protective effects after SCI. Young adult female rats received either sham or T9 spinal cord contusion injuries and were treated with estradiol, dihydrotestosterone, both, or nothing via Silastic capsules. Basso-Beattie-Bresnahan locomotor testing was performed weekly and voiding behavior was assessed at 3 weeks post-injury. Four weeks after SCI, lesion volume and tissue sparing, quadriceps muscle fiber cross-sectional area, and motoneuron dendritic morphology were assessed. Spontaneous locomotor behavior improved after SCI, but hormone treatments had no effect. Voiding behavior was disrupted after SCI, but was significantly improved by treatment with either estradiol or dihydrotestosterone; combined treatment was maximally effective. Treatment with estradiol reduced lesion volume, but dihydrotestosterone alone and estradiol combined with dihydrotestosterone were ineffective. SCI-induced decreases in motoneuron dendritic length were attenuated by all hormone treatments. SCI-induced reductions in muscle fiber cross-sectional areas were prevented by treatment with either dihydrotestosterone or estradiol combined with dihydrotestosterone, but estradiol treatment was ineffective. These findings suggest that deficits in micturition and regressive changes in motoneuron and muscle morphology seen after SCI are ameliorated by treatment with estradiol or dihydrotestosterone, further supporting a role for steroid hormones as neurotherapeutic agents in the injured nervous system.

Age-related changes in function and gene expression of the male and female mouse bladder

We investigated age-related changes in in vivo and in vitro functions and gene expression of the bladder of male and female mice. Mature and aged (12 and 27–30 month old) C57BL/6 mice of both sexes were used. Frequency volume, conscious free-moving cystometry and detrusor contractile and relaxant properties in in vitro organ bath were evaluated. mRNA expression level of muscarinic, purinergic, and β-adrenergic receptors and gene expression changes by cDNA microarray analysis of the bladder were determined. Cystometry demonstrated storage and voiding dysfunctions with ageing in both sexes. Detrusor strips from aged mice showed weaker contractile responses particularly in the cholinergic component and weaker relaxant responses to isoproterenol. These age-related impairments were generally severer in males. mRNA expression of bladder tissue was decreased for M3 muscarinic receptors in aged males and β2-adrenoceptors in aged females. cDNA microarray analysis results, albeit substantial sex difference, indicated “cell-to-cell signaling and interaction” as the most common feature of age-related gene expression. In summary, aged mice demonstrated voiding and storage dysfunctions resembling to detrusor hyperactivity with impaired contractility (DHIC), which were more pronounced in males. Genomic changes associated with aging may contribute to the age-related bladder functional deterioration in mice.

Porcine dorsal root ganglia ovarian neurons are affected by long lasting testosterone treatment

We studied the effect of testosterone overdose on the number, distribution and chemical coding of ovarian neurons in the dorsal root ganglia (DRGs) in pigs. On day 3 of the estrous cycle, the ovaries of both the control and experimental gilts were injected with retrograde tracer Fast Blue. From day 4 of the estrous cycle to the expected day 20 of the second studied cycle, the experimental gilts were injected with testosterone, while the control gilts received oil. After the completion of the protocol the Th16-L5 DRGs were collected. Injections of testosterone increased the testosterone (~3.5 fold) and estradiol-17beta (~1.6 fold) levels in the peripheral blood, and reduced the following in the DRGs: the total number of the Fast Blue-positive perikarya, the population of perikarya in the L2-L4 ganglia, and the numbers of SP(+)/CGRP(+), SP(+)/PACAP(+), SP(+)/nNOS(+) and SP(-)/nNOS(+) perikarya. In the testosterone-injected gilts, the populations of SP(+)CGRP(-), small and large androgen receptors-expressing perikarya were increased. These results suggest that elevated androgen levels during pathological states may regulate the transmission of sensory modalities from the ovary to the spinal cord, and antidromic regulation of the ovarian functions.

Morphological changes in peri-prostatic sympathetic ganglion cells in aging males

A significant part of morbidity in elderly male patients involves the pelvic organs and their autonomic neural regulation. The aim of the current study was to report the histopathological changes in the peri-prostatic ganglia in elderly males. The sympathetic ganglia from 36 prostatectomy specimens, 26 due to carcinoma of the prostate and 10 prostates from total cystectomies for transitional cell carcinoma, were examined. The age range was 54-88 years. A total of 5,075 ganglion cells were counted in all the specimens. Pathological changes were identified in 1,696 neuron cells as follows: Neuronophagia in 746 neuron cells, neuron cell vacuolization (330 cells), satellite cells vacuolization (423 cells), cell pyknosis (148 cells) and nageotte nodules (49 cells). A number of these changes increased with age. All the changes were more marked in the peri-prostatic ganglion cells of patients with prostatic adenocarcinoma compared with those with benign prostate hyperplasia, which may be due to local environmental changes associated with the presence of malignancy.

Effect of short-term androgen deficiency on bladder contractility and urothelial mediator release

In men, testosterone levels decline by 1% per year after the age of 40. Reduced androgen levels may directly contribute to lower urinary tract symptoms and bladder dysfunction, although the mechanisms are unclear. This study examined the effect of low testosterone and testosterone replacement on key mechanisms involved in local bladder function. Intraluminal release of the mediators ATP and ACh in response to bladder distension was measured in whole bladders from rats 8 weeks following castration, whilst bladder contractility was assessed using isolated strips. Human urothelial cells were cultured under low, physiological and supra-physiological testosterone conditions for 24 h or 5 days, and stretch-induced release of ATP and ACh was measured. Phasic contractile activity of bladder strips, agonist-induced reponses to carbachol and isoprenaline and nerve-evoked contractions were unaffected by castration. The acetylcholinesterase inhibitor neostigmine significantly increased amplitude of phasic activity only in bladder strips following castration, and this was prevented by testosterone replacement. Intraluminal ACh release following bladder distension was significantly reduced following castration, whilst ATP release was unaffected. In contrast, stretch-induced ATP release from urothelial cells was significantly enhanced in low testosterone conditions, whilst ACh release was unaltered. Testosterone-replacement to physiological levels prevented these changes. Whilst androgen deficiency of 8 weeks does not directly affect contractility of bladder smooth muscle, urothelial mediator release is sensitive to changes in testosterone. These changes in mediator release may be an early effect of the decline in testosterone and could affect sensory pathways in the longer term, contributing to the urinary symptoms and bladder dysfunction seen in androgen-deficient men.

Effect of orchiectomy and testosterone replacement on lower urinary tract function in anesthetized rats

Lower urinary tract (LUT) symptoms (LUTS), including frequency, urgency, incomplete voiding, and slow stream, are common in both men and women with advancing age. The most common cause for LUTS in aging men is benign prostatic hyperplasia. Some studies have also revealed an inverse association of serum testosterone levels with LUTS; however, the underlying mechanisms by which gonadal hormones affect the LUT have not been clarified. In the present study, we examined the effect of orchiectomy and testosterone replacement on LUT function in adult male Sprague-Dawley rats. Six weeks after bilateral orchiectomy or sham operations and 3 wk after injection of long-acting testosterone undecanoate (100 mg/kg im), transvesical cystometry and external urethral sphincter electromyogram (EUS EMG) recordings were performed under urethane anesthesia. The micturition reflex was elicited in both sham and orchiectomized animals. In orchiectomized rats, volume threshold for inducing micturition decreased by 47.6%; however, contraction amplitude, duration, and voiding efficiency were similar in sham and orchiectomized rats. The active period during EUS EMG bursting was lengthened during micturition in orchiectomized animals. Testosterone treatment, which normalized plasma testosterone levels, reversed these changes but also increased the duration of EUS EMG bursting. Orchiectomy also reduced mean voiding flow rate estimated from the duration of EUS EMG bursting, an effect that was not reversed by testosterone. The results indicate that orchiectomy affects both the active and passive properties of the bladder and urethra, and that many, but not all, of the changes can be reversed by testosterone.

Neuroprotective Role of Steroidal Sex Hormones: An Overview

Progesterone, estrogens, and testosterone are the well-known steroidal sex hormones, which have been reported to have "nonreproductive "effects in the brain, specifically in the neuroprotection and neurotrophy. In the last one decade, there has been a surge in the research on the role of these hormones in neuroprotection and their positive impact on different brain injuries. The said interest has been sparked by a desire to understand the action and mechanisms of these steroidal sex hormones throughout the body. The aim of this article was to highlight the potential outcome of the steroidal hormones, viz. progesterone, estrogens, and testosterone in terms of their role in neuroprotection and other brain injuries. Their possible mechanism of action at both genomic and nongenomic level will be also discussed. As far as our knowledge goes, we are for the first time reporting neuroprotective effect and possible mechanism of action of these hormones in a single article.

Basic Science Evidence for the Link Between Erectile Dysfunction and Cardiometabolic Dysfunction

INTRODUCTION

Although clinical evidence supports an association between cardiovascular/metabolic diseases (CVMD) and erectile dysfunction (ED), scientific evidence for this link is incompletely elucidated.

AIM

This study aims to provide scientific evidence for the link between CVMD and ED.

METHODS

In this White Paper, the Basic Science Committee of the Sexual Medicine Society of North America assessed the current literature on basic scientific support for a mechanistic link between ED and CVMD, and deficiencies in this regard with a critical assessment of current preclinical models of disease.

RESULTS

A link exists between ED and CVMD on several grounds: the endothelium (endothelium-derived nitric oxide and oxidative stress imbalance); smooth muscle (SM) (SM abundance and altered molecular regulation of SM contractility); autonomic innervation (autonomic neuropathy and decreased neuronal-derived nitric oxide); hormones (impaired testosterone release and actions); and metabolics (hyperlipidemia, advanced glycation end product formation).

CONCLUSION

Basic science evidence supports the link between ED and CVMD. The Committee also highlighted gaps in knowledge and provided recommendations for guiding further scientific study defining this risk relationship. This endeavor serves to develop novel strategic directions for therapeutic interventions.

The emerging role of the androgen receptor in bladder cancer

Men are three to four times more likely to get bladder cancer than women. The gender disparity characterizing bladder cancer diagnoses has been investigated. One hypothesis is that androgen receptor (AR) signaling is involved in the etiology and progression of this disease. Although bladder cancer is not typically described as an endocrine-related malignancy, it has become increasingly clear that AR signaling plays a role in bladder tumors. This review summarizes current findings regarding the role of the AR in bladder cancer. We discuss work demonstrating AR expression in bladder cancer and its role in promoting formation and progression of tumors. Additionally, we discuss the therapeutic potential of targeting the AR in this disease.

Bladder outlet obstruction causes up-regulation of nicotinic acetylcholine receptors in bladder-projecting pelvic ganglion neurons

Pelvic ganglion (PG) neurons relay sympathetic and parasympathetic signals to the lower urinary tract, comprising the urinary bladder and bladder outlet, and are thus essential for both storage and voiding reflexes. Autonomic transmission is mediated by activation of the nicotinic acetylcholine receptor (nAChR) in PG neurons. Previously, bladder outlet obstruction (BOO), secondary to benign prostatic hyperplasia, was found to increase soma sizes of bladder-projecting PG neurons. To date, however, it remains unknown whether these morphological changes are accompanied by functional plasticity in PG neurons. In the present study, we investigated whether BOO alters acetylcholine receptor (nAChR) transcript expression and current density in bladder PG neurons. Partial ligation of the rat urethra for six weeks induced detrusor overactivity (DO), as observed during cystometrical measurement. In rats exhibiting DO, membrane capacitance of parasympathetic bladder PG neurons was selectively increased. Real-time PCR analysis revealed that BOO enhanced the expression of the transcripts encoding the nAChR α3 and β4 subunits in PG neurons. Notably, BOO significantly increased ACh-evoked current density in parasympathetic bladder PG neurons, whereas no changes were observed in sympathetic bladder and parasympathetic penile PG neurons. In addition, other ligand-gated ionic currents were immune to BOO in bladder PG neurons. Taken together, these data suggest that BOO causes upregulation of nAChR in parasympathetic bladder PG neurons, which in turn may potentiate ganglionic transmission and contribute to the development of DO.

Neuroprotective effects of testosterone on ischemia/reperfusion injury of the rabbit spinal cord

AIM

Previous studies demonstrated the neuroprotective effects of testosterone, but no previous study has examined the neuroprotective effects of testosterone on spinal cord ischemia/reperfusion injury. The purpose of this study was to evaluate whether testosterone could protect the spinal cord from ischemia/reperfusion injury.

METHODS

Rabbits were randomised into four groups of eight animals as follows: group 1 (control), group 2 (ischemia), group 3 (methylprednisolone) and group 4 (testosterone). In the control group only a laparotomy was performed. In all other groups, the spinal cord ischemia model was created by the occlusion of the aorta just caudal to the renal artery. Levels of malondialdehyde and catalase were analysed, as were the activities of caspase-3, myeloperoxidase, and xanthine oxidase. Histopathological and ultrastructural evaluations were performed. Neurological evaluation was performed with the Tarlov scoring system.

RESULTS

After ischemia-reperfusion injury, increases were found in caspase-3 activity, myeloperoxidase activity, malondialdehyde levels, and xanthine oxidase activity. In contrast, decreases in catalase levels were observed. After the administration of testosterone, decreases were observed in caspase-3 activity, myeloperoxidase activity, malondialdehyde levels, and xanthine oxidase activity, whereas catalase levels increased. Furthermore, testosterone treatment showed improved results concerning histopathological scores, ultrastructural score and Tarlov scores.

CONCLUSIONS

Our results revealed for the first time that testosterone exhibits meaningful neuroprotective activity following ischemia-reperfusion injury of the spinal cord.

Long-term testosterone administration affects the number of paracervical ganglion ovary-projecting neurons in sexually mature gilts

The influence of testosterone (T) overdose on the number and distribution of ovarian neurons in the paracervical ganglion (PCG) in pigs was examined. To identify the ovarian neurons, on day 3 of the estrous cycle, the ovaries of both the control and experimental gilts were injected with retrograde neuronal tracer Fast Blue. From next day to the expected day 20 of the second studied cycle, experimental gilts were injected with T, while control gilts received oil. The PCG was then collected and processed for double-labeling immunofluorescence. T injections increased the T (∼3.5-fold) and estradiol-17β (∼1.6-fold) levels in the peripheral blood, and reduced the following in the PCG: the total number of Fast Blue-positive neurons, the number of perikarya in the lateral part of the PCG, the numbers of VAChT(+)/SOM(+), VAChT(+)/VIP(+), VAChT(+)/nNOS(+), VAChT(+)/VIP(-), VAChT(+)/DβH(-), VAChT(-)/SOM(-), VAChT(-)/VIP(-), VAChT(-)/nNOS(-) and VAChT(-)/DβH(-) perikarya, In the T-affected PCG, the populations of ovarian perikarya coded VAChT(-)/SOM(+), VAChT(-)/VIP(+) and VAChT(-)/DβH(+), and expressing androgen receptor were increased. After T treatment within the PCG dropped the density of nerve fibers expressing VAChT and/or SOM, VIP, DβH. Obtained data suggest that elevated androgen levels occurring during pathological processes may regulate ovary function(s) by affecting the PCG gonad-supplying neurons.

Reduction of the number of neurones in the caudal mesenteric ganglion innervating the ovary in sexually mature gilts following testosterone administration

The effect of testosterone on the morphological and chemical plasticity of the porcine caudal mesenteric ganglion (CaMG) ovary-projecting neurones was investigated. To identify the neurones on day 3 of the oestrous cycle, the ovaries of both the control and experimental gilts were injected with Fast Blue retrograde neuronal tracer. From next day until day 20 of the anticipated second studied cycle, experimental gilts were injected with testosterone, whereas control gilts received oil. Testosterone injections increased testosterone (by approximately 3.5-fold) and 17β-oestradiol (by approximately 1.6-fold) levels in the peripheral blood and decreased the following in the CaMG: the total number of Fast Blue-positive perikarya (including small ones); the population of small perikarya in the caudal, ventral and dorsal ganglional regions; the numbers of dopamine-β-hydroxylase (DβH) and/or neuropeptide Y (NPY), somatostatin (SOM), galanin (GAL) small and large perikarya; the numbers of small perikarya containing DβH (but not NPY, SOM, GAL); and the density of DβH and/or NPY, SOM nerve fibres. A disappearance of small and large non-noradrenergic perikarya and an increase in the total number of androgen receptor-immunoreactive perikarya was noted. Our results suggest that elevated androgen levels occurring during pathological states may regulate ovary function(s) by affecting the CaMG gonad-supplying neurones.

Distribution of androgen and oestrogen receptors-α in the seminal vesicle-related spinal neurones in male rats

The seminal vesicles are male accessory sex glands that contribute much of the seminal fluid volume. Previous studies have suggested that the majority of autonomic innervations to the rat seminal vesicles originate from the bilateral major pelvic ganglia. Many preganglionic autonomic neurones innervating the pelvic ganglion were expressed androgen receptors (AR) or oestrogen receptor (ER)-α immunoreactivity. However, direct neuroanatomic data regarding the distribution of AR and ER-α in seminal vesicle related-spinal neurones are lacking. In the present study, a nonvirulent pseudorabies virus (PRV-152 strain) was used in a retrograde tracing experiment. Four days after PRV injection into the seminal vesicles of male rats, spinal cord sections were prepared. Double- and triple-fluorescence techniques using AR and ER-α with choline acetyltransferase (ChAT) and PRV were used to investigate the AR and ER-α distribution in the seminal vesicles related spinal neurones in male rats. In lamina X, 14% of the PRV-labelled neurones in the L1-L4 segments and 43% in the L5-S1 segments were double-labelled with AR. In the L1-L4 segments, 6% of PRV-labelled neurones and 26% in the L5-S1 segments were double-labelled with ER-α. In the intermedial cell column area, 10% of PRV-labelled neurones in the L1-L4 segments and 47% of PRV-labelled neurones in the L5-S1 segments were double-labelled with AR. Up to 16% of PRV-labelled neurones in the L5-S1 segments were double-labelled with ER-α. No PRV-labelled neurones in the L1-L4 segments were double-labelled with ER-α. However, for the AR and ER-α/PRV/ChAT triple-fluorescence experiments, very few seminal vesicle preganglionic neurones expressed AR or ER-α. Our data suggests that many spinal interneurones but not preganglionic neurones involved in the seminal vesicle control in male rats were double-labelled with AR or ER-α, and they were mainly located at the parasympathetic level in the spinal cord.

Localization of peripheral autonomic neurons innervating the boar urinary bladder trigone and neurochemical features of the sympathetic component

The urinary bladder trigone (UBT) is a limited area through which the majority of vessels and nerve fibers penetrate into the urinary bladder and where nerve fibers and intramural neurons are more concentrated. We localized the extramural post-ganglionic autonomic neurons supplying the porcine UBT by means of retrograde tracing (Fast Blue, FB). Moreover, we investigated the phenotype of sympathetic trunk ganglia (STG) and caudal mesenteric ganglia (CMG) neurons positive to FB (FB+) by coupling retrograde tracing and double-labeling immunofluorescence methods. A mean number of 1845.1±259.3 FB+ neurons were localized bilaterally in the L1-S3 STG, which appeared as small pericarya (465.6±82.7 µm²) mainly localized along an edge of the ganglion. A large number (4287.5±1450.6) of small (476.1±103.9 µm²) FB+ neurons were localized mainly along a border of both CMG. The largest number (4793.3±1990.8) of FB+ neurons was observed in the pelvic plexus (PP), where labeled neurons were often clustered within different microganglia and had smaller soma cross-sectional area (374.9±85.4 µm²). STG and CMG FB+ neurons were immunoreactive (IR) for tyrosine hydroxylase (TH) (66±10.1% and 52.7±8.2%, respectively), dopamine beta-hydroxylase (DβH) (62±6.2% and 52±6.2%, respectively), neuropeptide Y (NPY) (59±8.2% and 65.8±7.3%, respectively), calcitonin-gene-related peptide (CGRP) (24.1±3.3% and 22.1±3.3%, respectively), substance P (SP) (21.6±2.4% and 37.7±7.5%, respectively), vasoactive intestinal polypeptide (VIP) (18.9±2.3% and 35.4±4.4%, respectively), neuronal nitric oxide synthase (nNOS) (15.3±2% and 32.9±7.7%, respectively), vesicular acetylcholine transporter (VAChT) (15±2% and 34.7±4.5%, respectively), leuenkephalin (LENK) (14.3±7.1% and 25.9±8.9%, respectively), and somatostatin (SOM) (12.4±3% and 31.8±7.3%, respectively). UBT-projecting neurons were also surrounded by VAChT-, CGRP-, LENK-, and nNOSIR fibers. The possible role of these neurons and fibers in the neural pathways of the UBT is discussed.

Sex differences in the physiology and pharmacology of the lower urinary tract

Sexual dimorphism is not only noticed in the prevalence of many diseases, but also in multiple physiological functions in the body. This review has summarized findings from published literature on the sex differences of the pathophysiology and pharmacology of the lower urinary tract (LUT) of humans and animals. Sex differences have been found in several key areas of the LUT, such as overactive bladder, expression and function of neurotransmitter receptors in the bladder and urethra, and micturition patterns in humans and animals. It is anticipated that this review will not only evoke renewed interest for further research on the mechanism of sex differences in the pathophysiology of the LUT (especially for overactive bladder), but might also open up the possibilities for gender-based drug development by pharmaceutical industries in order to find separate cures for men and women with diseases of the LUT.

Long-term estradiol-17β administration changes the population of paracervical ganglion neurons supplying the ovary in adult gilts

The aim of this study was to determine the influence of estradiol-17β (E(2)) overdose on the number and distribution of ovarian parasympathetic neurons in the paracervical ganglion (PCG) in adult pigs. To identify the neurons innervating gonads on day 3 of the estrous cycle, the ovaries of both the control and experimental gilts were injected with retrograde neuronal tracer Fast Blue. From next day to the expected day 20 of the second studied cycle, experimental gilts were injected with E(2), while control gilts received oil. The PCG were then collected and processed for double-labeling immunofluorescence. Injections of E(2) increased the E(2) level in the peripheral blood approximately four- to fivefold and reduced the following in the PCG: the total number of Fast Blue-positive neurons; the number of perikarya in the lateral part of the PCG; the numbers of vesicular acetylcholine transporter (VAChT)(+)/somatostatin(+), VAChT(+)/vasoactive intestinal polypeptide (VIP)(+), VAChT(+)/neuronal isoform of nitric oxide synthase(+), VAChT(+)/VIP(-), VAChT(+)/dopamine β-hydroxylase (DβH)(-), VAChT(-)/VIP(-), and VAChT(-)/DβH(-) perikarya; and the total number of perikarya expressing estrogen receptors (ERs) subtype α and/or β. In summary, long-term E(2) treatment of adult gilts downregulates the population of both cholinergic and ERs expressing the PCG ovary-projecting neurons. Our results suggest that elevated E(2) levels occurring during pathological states may regulate gonadal function(s) by affecting ovary-supplying neurons.

Testostérone et contrôle central de l’érection

La testostérone orchestre l’organisation périnatale et l’activation adulte des structures nerveuses cérébrales et spinales impliquées dans l’expression du comportement sexuel mâle. Cette revue décrit brièvement les différents effets de la testostérone dans la régulation de la motivation sexuelle et de l’érection, et les modèles génétiques générés, jusqu’à présent, dans le but d’élucider ses mécanismes d’action centraux.

PGF(2α), LH, testosterone, oestrone sulphate, and cortisol plasma concentrations around sexual stimulation in jackass

Many hormones are involved in the regulation of male reproductive functions, controlling sexual behavior, and influencing sexual arousal, the onset of erection and ejaculation, and the post-ejaculatory detumescence. The aims of this study were to analyze the plasma concentrations of 15-ketodihydro-PGF(2α) (PGFM), LH, testosterone (T), oestrone sulphate (OS), and cortisol (C) in relation to sexual stimulation and to evaluate the possible correlations among circulating hormones and between hormones and semen characteristics in the donkey stallion. Thirteen sexually experienced Martina Franca jackass of proven fertility were enrolled and semen was collected through an artificial vagina. Plasma samples were collected at 12, 9, 6 and 3 min before oestrous jenny exposure, at the first erection in the mating arena in the presence of an oestrous jenny, during ejaculation, at dismounting, 3, 6, 9 and 12 min after ejaculation in box, and then every 10 min during the following 50 min. PGFM showed an increasing trend with significant differences between the pre-ejaculatory and post-ejaculatory period, suggesting a role of this hormone in the control of ejaculation. LH showed a significantly higher concentration at ejaculation compared to last samples, while T showed significantly higher levels at erection, ejaculation and dismounting, probably for its influence on these processes and on sexual behavior. Finally, OS did not show any difference in the period of observation, while C presented a significant increase only 22 minutes after erection. The only hormonal correlation found was a positive one between LH and T at erection and dismounting, while T and OS were positively correlated with total and progressive motility, respectively.

Distribution and chemical coding of sympathetic neurons in the caudal mesenteric ganglion projecting to the ovary in sexually mature gilts

The distribution and co-localisation patterns of dopamine-beta-hydroxylase (DβH), neuropeptide Y (NPY), somatostatin (SOM) and galanin (GAL) were investigated by use of retrograde neuronal tracing and double-labelling immunofluorescence techniques in the caudal mesenteric ganglion (CaMG) neurons supplying the ovary of adult pigs. The existence and density of nerve fibres that are immunoreactive (IR) for the above-mentioned neuroactive substances were also evaluated. Injections of a fluorescent tracer (Fast Blue; FB) into the ovaries revealed the presence of small- (76.38%) and large-sized (23.62%) FB-positive postganglionic neurons in the CaMG. Noradrenergic FB-positive cells were simultaneously NPY- (43.38%), SOM- (18.77%) and GAL- (18.31%) IR. Of the examined FB-positive neurons, 53.49% were DβH-IR but NPY-immunonegative (IN), 79.06% were DβH-IR but SOM-IN, and 77.16% were DβH-IR but GAL-IN. Small- or large-sized subsets of traced neurons were supplied by only one or a few nerve fibres, exhibiting DβH-, NPY-, SOM- and/or GAL-IR. Our data show the specific morphological as well as immunochemical structural organisation of the sympathetic neurons in the CaMG in adult gilts. The occurrence of an abundant population of noradrenergic perikarya in the CaMG may suggest their important physiological role in the regulation of gonadal function(s) in these animals.

Androgens selectively protect against apoptosis in hippocampal neurones

Androgens can protect neurones from injury, although androgen neuroprotection is not well characterised in terms of either specificity or mechanism. In the present study, we compared the ability of androgens to protect neurones against a panel of insults, empirically determined to induce cell death by apoptotic or non-apoptotic mechanisms. Three criteria defining but not inclusive of apoptosis are: protection by caspase inhibition, protection by protein synthesis inhibition and the presence of pyknotic nuclei. According to these criteria, beta-amyloid, staurosporine, and Apoptosis Activator II induced cell death involving apoptosis, whereas hydrogen peroxide (H(2)O(2)), iron, calcium ionophore and 3-nitropropionic acid induced cell death featuring non-apoptotic characteristics. Pretreatment of hippocampal neurones with testosterone or dihydrotestosterone attenuated cell death induced by beta-amyloid, staurosporine and Apoptosis Activator II, but none of the other insults. The anti-oxidant Trolox did not reduce cell death induced by beta-amyloid, staurosporine and Apoptosis Activator II, but did protect against H(2)O(2) and iron. Similarly, a supra-physiological concentration of oestrogen reduced cell death induced by H(2)O(2) and iron, an effect not observed with androgens. We also show that activation of oestrogen pathways was not necessary for androgen neuroprotection. These data suggest that androgens directly activate a neuroprotective mechanism specific to inhibition of cell death involving apoptosis. Determining the specificity of androgen neuroprotection may enable the development of androgen compounds for the treatment of neurodegenerative disorders.

Oxytocin, vasopressin, prostaglandin F(2alpha), luteinizing hormone, testosterone, estrone sulfate, and cortisol plasma concentrations after sexual stimulation in stallions

This experiment was designed to determine the effects of sexual stimulation on plasma concentrations of oxytocin (OT), vasopressin (VP), 15-ketodihydro-PGF(2alpha) (PG-metabolite), luteinizing hormone (LH), testosterone (T), estrone sulfate (ES), and cortisol (C) in stallions. Semen samples were collected from 14 light horse stallions (Equus caballus) of proven fertility using a Missouri model artificial vagina. Blood samples were collected at 15, 12, 9, 6, and 3 min before estrous mare exposure, at erection, at ejaculation, and at 3, 6, and 9 min after ejaculation. Afterwards, blood sampling was performed every 10 min for the following 60 min. Sexual activity determined an increase in plasma concentrations of OT, VP, C, PG-metabolite, and ES and caused no changes in LH and T concentrations. The finding of a negative correlation between C and VP at erection, and between C and T before erection and at the time of erection, could be explained by a possible inhibitory role exerted by C in the mechanism of sexual arousal described for men.

Dihydrotestosterone activates CREB signaling in cultured hippocampal neurons

Although androgens induce numerous actions in brain, relatively little is known about which cell signaling pathways androgens activate in neurons. Recent work in our laboratory showed that the androgens testosterone and dihydrotestosterone (DHT) activate androgen receptor (AR)-dependent mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling. Since the transcription factor cyclic AMP response element binding protein (CREB) is a downstream effector of MAPK/ERK and androgens activate CREB in non-neuronal cells, we investigated whether androgens activate CREB signaling in neurons. First, we observed that DHT rapidly activates CREB in cultured hippocampal neurons, as evidenced by CREB phosphorylation. Further, we observed that DHT-induced CREB phosphorylation is AR-dependent, as it occurs in PC12 cells stably transfected with AR but in neither wild-type nor empty vector-transfected cells. Next, we sought to identify the signal transduction pathways upstream of CREB phosphorylation using pharmacological inhibitors. DHT-induced CREB phosphorylation in neurons was found to be dependent upon protein kinase C (PKC) signaling but independent of MAPK/ERK, phosphatidylinositol 3-kinase, protein kinase A, and Ca(2+)/calmodulin-dependent protein kinase IV. These results demonstrate that DHT induces PKC-dependent CREB signaling, which may contribute to androgen-mediated neural functions.

Changes in the number and volume of NPY and VIP neurons from periprostatic accessory vegetative ganglia in pre- and peripubertal rats. A stereological study

The amount of neurons of periprostatic accessory ganglia in pre- and peripubertal rats was studied to ascertain whether the development of these autonomic ganglia is androgen-dependent. Stereological estimates of the volumes and number of neurons immunoreactive to protein gene product 9.5 (PGP 9.5), neuropeptide Y (NPY), and vasoactive intestinal polypeptide (VIP) were carried out. Immunostaining of androgen receptors (AR) in the ganglia was also performed. The ganglionic neurons from the two groups studied were immunoreactive to PGP 9.5, NPY, and VIP. Almost all the neurons were immunostained for AR. The ganglionic volume showed a significant increase in peripubertal prostate in comparison with the prepubertal gland. No significant changes were observed with respect to the absolute number of neurons immunoreactive to all the antigens. The neuronal volume was significantly increased in peripubertal rats in comparison with prepubertal animals. These findings led us to the following conclusions: There is no evidence of neurogenesis during pubertal development in the periprostatic accessory ganglia of the rat. The increase of ganglionic volume in puberty is due to the growth in neuronal volume. There were no differences between the sizes of NPY and VIP neurons in pubertal periprostatic accessory ganglia. The development of periprostatic vegetative neurons is androgen-dependent.

Prostatic inflammation and obstructive voiding in the adult Noble rat: impact of the testosterone to estradiol ratio in serum

BACKGROUND

The age-related decline of the testosterone to estradiol (T-to-E(2)) ratio in serum is associated with the increased prevalence of prostatic inflammation and lower urinary tract symptoms suggesting obstructive voiding. The impact of the T-to-E(2) ratio on the development and reversal of non-bacterial prostatic inflammation and obstructive voiding was tested in adult Noble rats.

METHODS

Adult male Noble rats (n = 16) were treated with estradiol (83 microg/day) and two different doses (280 and 830 microg/day) of testosterone to cause hypoandrogenic and hyperandrogenic states with elevated estrogen. After the 13-week hormonal treatment, urodynamical measurements and electrical activity recording of the rhabdosphincter muscle were performed under anesthesia. Testosterone, estradiol, and prolactin concentrations in serum were measured and inflammatory changes in the dorsolateral prostate were classified and counted.

RESULTS

Histopathological and urodynamical analyses indicated that the hypoandrogenic animals with a decreased T-to-E(2) ratio (10 versus > 300 in control) developed prostatic inflammation and non-obstructive voiding. The hyperandrogenic state with decreased T-to-E(2) ratio of 50 decreased the aggressiveness of the inflammation and the number of inflamed acini in the prostate and caused urethral obstruction associated with rhabdosphincter dysfunction.

CONCLUSIONS

Different responses of the prostatic inflammation and voiding function to the change in T-to-E(2) ratio imply that non-bacterial prostatic inflammation is not a sufficient condition for the development of obstructive voiding. The present study finds no support for the idea that age- and/or obesity-related hypoandrogenic state with a decreased ratio of T-to-E(2) would cause urethral obstruction.

Lower urinary tract symptoms and its potential relation with late-onset hypogonadism

The study of the health status of the aging male takes presently a more integrative approach and it appears that ailments typical of male aging, such as lower urinary tract symptoms (LUTS), (visceral) obesity, metabolic syndrome and erectile failure are significantly interrelated. A common denominator of the above ailments is lower-than-normal testosterone levels occurring in a significant proportion of elderly men. This review addresses the potential connections between LUTS and late-onset hypogonadism. In animal studies there appear to be androgen and estrogen receptors in the urothelium and smooth muscle cells of the urethra and bladder of the rat and rabbit, as well as in the neurons in the autonomic ganglia of the prostatic plexus of the male rat. Upon castration electrically evoked relaxations of the smooth muscle of the prostatic urethra were decreased. There is a Rho-kinase activation/endothelin pathway; possibly involved in the increased smooth muscle activity found in both LUTS/benign prostate hyperplasia. Nitric oxide (NO) appears to have a smooth muscle relaxing effect in the urogenital organs. Studies in humans have convincingly shown that phosphodiestererase inhibitors have a beneficial effect on LUTS. More intervention studies should be undertaken to test the clinical validity of the theoretically plausible interrelationship between LUTS and late-onset hypogonadism.

The effects of testosterone deficiency on the structural integrity of the penile dorsal nerve in the rat

Androgens play a vital role in erectile function and are known to have a neuroprotective role in the nervous system. This study investigated, in a rat model, the effects of testosterone deprivation and replacement on the morphology of the dorsal nerve of the rat penis at the light microscopy level. Two weeks after castration, male rats were infused with vehicle alone or 44 mug of testosterone for 2 weeks. Age-matched, sham-operated control animals were used for comparisons. Penile tissue samples were removed for histological analyses. The following parameters were assessed: (1) total myelin sheath thickness; (2) density of nerve fibers; and (3) axon cross-sectional area per nerve fiber. Castration resulted in a significant increase in axon cross-sectional area compared to that of the control and testosterone-treated animals (6.97+/-0.59 microm(2) per fiber in control animals to 14.32+/-0.44 microm(2) per fiber in castrated animals). Qualitatively, there were signs of nerve degeneration, particularly myelin sheath degeneration, in all sample groups. We did not observe statistically significant changes in myelin sheath thickness. There was a trend of reduced nerve density. Nerve degeneration was not quantified since this study was performed at the light microscopic level. This study suggests that testosterone has a neuroprotective role in the nerve fibers of the dorsal nerve and testosterone deficiency may lead to different forms of nerve degeneration resulting in anatomic alterations, thus contributing to erectile dysfunction.

Androgen and estrogen receptor-mediated mechanisms of testosterone action in male rat pelvic autonomic ganglia

Although male reproductive function is primarily androgen dependent, many studies suggest that estrogens have direct actions on the male reproductive organs. Pelvic autonomic neurons provide the motor control of the internal reproductive organs and the penis and various properties of these neurons are affected by endogenous androgens. However, the possible role of estrogens at this site has not been examined. Here we have investigated the significance of estrogens produced by aromatization of testosterone (T) in the physiological actions of androgens on adult male rat pelvic ganglion neurons. Reverse transcriptase polymerase chain reaction (RT-PCR) studies showed that aromatase and both estrogen receptors (ERalpha and ERbeta) are expressed in these ganglia. Western blotting also showed that aromatase is expressed in male pelvic ganglia. Using immunohistochemical visualization, ERalpha was predominantly expressed by nitric oxide synthase (NOS)-positive parasympathetic pelvic ganglion neurons. In vivo studies showed that the decrease in pelvic ganglion soma size caused by gonadectomy could be prevented by administration of T or dihydrotestosterone (DHT), but not 17beta-estradiol (E2), showing that this maintenance action of testosterone is mediated entirely by androgenic mechanisms. However, in vitro studies of cultured pelvic ganglion neurons revealed that T, DHT and E each stimulated the growth of longer and more complex neurites in both noradrenergic and cholinergic NOS-expressing neurons. The effects of T were attenuated by either androgen or estrogen receptor antagonists, or by inhibition of aromatase. Together these studies demonstrate that estrogens are likely to be synthesized in the male pelvic ganglia, produced from T by local aromatase. The effects of androgens on axonal growth are likely to be at least partly mediated by estrogenic mechanisms, which may be important for understanding disease-, aging- and injury-induced plasticity in this part of the nervous system.

Urodynamic changes in a noble rat model for nonbacterial prostatic inflammation

BACKGROUND

Chronic nonbacterial prostatitis (CP) associated with voiding dysfunction is a poorly understood clinical phenomenon. The goal of the present study was to induce prostatic inflammation with estrogen and androgen treatment and to record associated urodynamic changes in Noble rats.

METHODS

Rats were treated with estradiol and testosterone implants to increase estradiol concentration in serum while testosterone concentration was maintained at or slightly above the control level. The urodynamical recordings were performed under anesthesia after the hormone treatments for 3 and 6 weeks. The dorsolateral lobes of the prostates were removed for histopathological analysis after recordings.

RESULTS

After the 3-week treatment, lymphocytes, mainly T-cells, were located around the capillaries. During the following 3 weeks lymphocytes migrated into stroma and acini. Cytotoxic T-cells were seen intraepithelially, and neutrophiles inside the acini. Removal of estrogen implant or treatment with anti-estrogen diminished inflammation. No changes in voiding pattern were seen after the 3-week treatment. Three weeks later, bladder weight and capacity were increased, and the micturition time was prolonged.

CONCLUSIONS

Elevated estrogen concentration was essential for the gradual development of prostatic inflammation. The profile and location of inflammatory cells suggest that prostatic vasculature is one of the sites of estrogen action. Urodynamic changes which developed in association with glandular inflammation indicated abnormal bladder function, reflecting an incipient obstruction.

A critical review of the pharmacology of the plant extract ofPygeum africanumin the treatment of LUTS

Despite an unremitting increase in the number of patients presenting symptoms of benign prostate hyperplasia (BPH), the viable treatment options remain relatively limited when compared to other disorders of aging. This has spurred an interest in so-called alternative medicines, many of which continue to be used in spite of the more recent emergence of rationally targeted therapies. Nonetheless, in the case of plant extracts, the vast majority of these have not been subjected to the same rigorous pre-clinical pharmacological testing and large-scale clinical trials now required by health authorities. Furthermore, demonstration of their clinical efficacy in BPH has been hindered by trials of limited duration with a high placebo response. Beginning with a preliminary demonstration of in vitro inhibition of growth factor-mediated fibroblast proliferation with Pygeum africanum extract, a detailed series of in vitro and in vivo studies on prostate growth and bladder function were undertaken. These studies, reviewed herein, have permitted the identification of putative molecular targets of Pygeum africanum extract affecting both growth factor-mediated prostate growth as well as specific parameters of bladder function. These results, corroborated in part by short-term clinical efficacy, set the stage for a large-scale clinical trial to investigate the efficacy of Pygeum africanum extract in the treatment of lower urinary tract symptoms.

The effect of streptozotocin-induced diabetes on the rat seminal vesicle: A possible pathophysiological basis for disorders of ejaculation

In the streptozotocin (STZ)-diabetic rat major increases in noradrenaline concentration and content of the seminal vesicles were evident as early as 7 weeks following induction of hyperglycemia and returned toward normal after 34 weeks of hyperglycemia. There were significant reductions in the concentration and content of dopamine at 19-42 weeks of diabetes, and small occasionally significant reductions in the content of serotonin and adrenaline, particularly around 19-26 weeks after STZ treatment. The uptake of tritiated noradrenaline in the diabetics was increased at 12 weeks compared to the controls, and decreased to control levels with increasing age. Release of tritiated noradrenline was increased in response to electrical field stimulation and high potassium solutions, and raising calcium concentration caused increased release at rest and during electrical stimulation. Immunohistochemical demonstration of tyrosine hydroxylase was increased during the period when the noradrenaline concentration and content were elevated. It is concluded that there are significant changes in the sympathetic innervation of the seminal vesicle during the course of STZ diabetes, and that alterations in the reuptake, release, and synthesis of the neurotransmitter noradrenaline may contribute to changes in the concentration of the amine in the tissue. It is possible that the changes observed are related to the remodeling and regrowth of sympathetic nerve endings damaged in the early stages of hyperglycemia. These changes may also contribute to disorders of ejaculation in diabetes.