Anatomy of Cowper's gland in humans suggesting a secretion and emission mechanism facilitated by cooperation of striated and smooth muscles.

This study presents the detailed anatomy of the Cowper's gland in humans. Elucidating the mechanism of secretion and emission of the Cowper's gland requires analysis of the muscles around the Cowper's gland. We hypothesized that the Cowper's gland involves not only smooth muscle but also the striated muscles of the pelvic floor. Here, we provide comprehensive and three-dimensional anatomy of the Cowper's gland and its surrounding structures, which overcomes the current local and planar understanding. In this study, seven male corpses of body donors were used to conduct macroscopic anatomy, histology, and three-dimensional reconstruction. The Cowper's gland was surrounded laterally and posterosuperiorly by striated and smooth muscles, respectively. The striated muscle bundle was connected from the superficial transverse perineal muscle, levator ani, and external anal sphincter to the external urethral sphincter (rhabdosphincter). The smooth muscle was part of the deep transverse perineal muscle and entered between the bilateral Cowper's glands and lobules. Our findings indicate that the secretion and emission of the Cowper's gland in humans are carried out through the cooperation of striated and smooth muscles.

Somatic innervation contributes to the release of bulbourethral gland secretion in male rats.

BACKGROUND: In male rats, the bulbourethral glands (Bu-Gs) are the unique accessory sexual glands surrounded by striated musculature. However, until now the role of this musculature was unknown. OBJECTIVES: (i) To characterize the Bu-Gs striated muscular layer in male rats and determine its innervation and response to genital stimulation. (ii) To reveal the role of the Bu-Gs striated musculature in the release of glandular secretion. (iii) To elucidate the effect of bilateral ablation of the Bu-Gs on copulatory behavior and seminal fluid characteristics. MATERIALS AND METHODS: Adult Wistar male rats were allocated in three experiments: in Experiment 1, the Bu-Gs striated musculature, innervation and reflex activity were determined by gross anatomy and histological and electrophysiological techniques; electromyographic activity of the Bu-Gs striated musculature was evoked with genital stimulation. In Experiment 2, Bu-Gs were analyzed after copulatory behavior of intact or animals with unilateral transected motor branch of the sacral plexus (MBSP). In Experiment 3, copulatory behavior and spermatobioscopy of males with bilateral ablation of the Bu-Gs or sham surgery were analyzed. RESULTS: The Bu-Gs striated fibers discharged in response to mechanostimulation of the prepuce, glans, and penile-urethra. Innervation of the Bu-Gs striated musculature originated from the MBSP; this nerve also innervates striated penile muscles. Unilateral transection of the MBSP significantly decreased the secretion from the ipsilateral Bu-G to the nerve transection. Bilateral ablation of Bu-Gs did not affect seminal plug formation but decreased semen viscosity. DISCUSSION AND CONCLUSION: The Bu-Gs striated musculature contributes to expel glandular secretion during sexual intercourse. The somatic control of Bu-Gs secretion is additional to the reported autonomic innervation supplied by the cavernosus nerve, which may underlie the synthesis of secretion as well as contraction of Bu-Gs smooth muscle.

Morfologia e histoquímica das glândulas sexuais acessórias de Metachirus nudicaudatus, Didelphidae-Marsupialia / Morphology and histochemistry of accessory sex glands of Metachirus nudicaudatus, Didelphidae-Marsupialia

São descritas a morfologia e a distribuição de glicogênio e mucossubstâncias na próstata e nas glândulas bulbouretrais de Metachirus nudicaudatus (Geoffroy, 1803), única espécie do gênero. A próstata é envolvida pelas túnicas adventícia e muscular, e o estroma é formado pelo conjuntivo da mucosa uretral. O parênquima é constituído pelos túbulos secretores, disseminados na mucosa uretral, e que diferem histológica e histoquimicamente nos segmentos cranial, médio e caudal. Essas diferenças morfo-histoquímicas também são observadas nas partes externa, média e interna de cada túbulo. De um modo geral, os três segmentos prostáticos secretam mucossubstâncias neutras, porém o segmento caudal produz também glicogênio. Os três pares de glândulas bulbouretrais (laterais, intermédias e mediais) do Metachirus são envolvidas por uma cápsula conjuntiva e músculo estriado esquelético. O maior par é a bulbouretral lateral que é constituída por longos túbulos secretores de mucossubstâncias neutras. As bulbouretrais intermédias são formadas por túbulos ramificados, que produzem mucossubstâncias neutras, ácidas carboxiladas e ácidas sulfatadas. Os túbulo-ácinos ramificados das bulbouretrais mediais secretam mucossubstâncias neutras. O Metachirus não possui glândulas ampulares, vesículas seminais nem glândulas de coagulação.(AU)

This paper describes the morphology and distribution of glycogen and mucous substances in the prostate and the bulbourethral glands of Metachirus nudicaudatus (Geoffroy, 1803), the only species of the genus. The prostate is surrounded by the tunica adventitia, and muscle and stroma is formed by connective urethral mucosa. The glandular parenchyma consists of secretory tubules, scattered throughout the connective tissue of the urethral mucosa which differs histologically and histochemically in cranial, middle, and caudal segments of the prostate. These morpho-histochemical differences are also observed in the outer, middle and inner parts of the tubular epithelium of each prostatic segment. In general, prostatic segments secrete neutral mucous substances, and the caudal segment also produces glycogen. The three pairs of bulbourethral glands (lateral, intermediate and medial) are surrounded by a capsule of dense connective tissue and skeletal striated muscle. The glandular parenchyma is formed by tubules or branched tubuloacinar, covered by simple epithelium which is characteristic for each pair of glands. The lateral bulbourethral glands and the medial bulbourethral glands produce neutral mucous substances and the secretion of the intermediate bulbourethral glands consists of neutral mucous substances, carboxylated acids, and sulfated acids. The M. nudicaudatus does not have ampullary glands, seminal vesicles or coagulating glands.(AU)

Structure, histochemistry, ultrastructure and seasonal variations of the male prostatic complex in the black Myotis bat, Myotis nigricans (Chiroptera: Vespertilionidae).

Chiroptera are one of the most diverse orders of mammals and a unique group within Mammalia that posses a wide geographic distribution and considerable variability in reproductive strategies. The aims of the present study were to characterise the male prostatic complex of the bat Myotis nigricans (Vespertilionidae) and evaluate seasonal variations in the prostatic complex of M. nigricans specifically. Twenty-three sexually mature specimens (four sample groups: winter, spring, summer and autumn) were subjected to macroscopic, microscopic, morphometric and ultrastructural analyses. The reproductive accessory glands of M. nigricans were found to be composed of a multilobed complex associated with the urethra and a pair of inguinal bulbourethral glands. The complex was composed of three bilobed prostatic regions (ventral, dorsolateral and dorsal) with no ampullary gland and seminal vesicles. This pattern of lobulation is very similar to that described for the prostate of rodents; however, it differs from that of other mammals and even other families of bats (e.g. Phyllostomidae and Molossidae). Each prostatic region in M. nigricans has unique and distinctive characteristics, which synchronise to establish the main reproductive peak of the species in summer. The data also indicated an asynchrony in the activity of primary and secondary reproductive organs in the annual reproductive cycle of M. nigricans in São Paulo State, Brazil.

Llama oviductal sperm reservoirs: involvement of bulbourethral glands.

The aim of this study was to elucidate the role of llama seminal plasma in the formation of oviductal sperm reservoirs. Female llamas with follicles in the mature phase were mated with a bulbourethral glands-removed male. Females mated with nonbulbourethral glands-removed males were used as control. Oviducts were obtained by surgery 24 h after mating. The uterotubal junction and isthmus were examined by scanning electron microscopy, and mucopolysaccharides were identified by Alcian blue staining. To know the proteins probably involved in sperm reservoir formation, SDS-PAGE of seminal plasma (8% and 18% resolving gel) was made. Spermatozoa only adhered to the oviductal mucosa surface of uterotubal junction of females mated with nonbulbourethral glands-removed males confirming that seminal plasma and, in particular, bulbourethral secretions are related with the oviductal sperm reservoir formation. Histological sections showed sperm in the lumen, immersed in substance, positive for acid mucopolysaccharides. Alcian blue staining of seminal plasma proteins SDS-PAGE showed a band of high molecular weight containing mucopolysaccharides, only present in nonbulbourethral glands-removed males. Bulbourethral glands would secrete at least eight different proteins that most likely participate in the process of sperm storage in the oviduct.

Characterization of bulbospongiosus muscle reflexes activated by urethral distension in male rats.

The urethrogenital reflex (UGR) is used as a surrogate model of the autonomic and somatic nerve and muscle activity that accompanies ejaculation. The UGR is evoked by distension of the urethra and activation of penile afferents. The current study compares two methods of elevating urethral intraluminal pressure in spinalized, anesthetized male Sprague-Dawley rats (n = 60). The first method, penile extension UGR, involves extracting the penis from the foreskin, so that urethral pressure rises due to a natural anatomical flexure in the penis. The second method, penile clamping UGR, involves penile extension UGR with the addition of clamping of the glans penis. Groups of animals were prepared that either received no additional treatment, surgical shams, or received bilateral nerve cuts (4 nerve cut groups): either the pudendal sensory nerve branch (SbPN), the pelvic nerves, the hypogastric nerves, or all three nerves. Penile clamping UGR was characterized by multiple bursts, monitored by electromyography (EMG) of the bulbospongiosus muscle (BSM) accompanied by elevations in urethral pressure. The penile clamping UGR activity declined across multiple trials and eventually resulted in only a single BSM burst, indicating desensitization. In contrast, the penile extension UGR, without penile clamping, evoked only a single BSM EMG burst that showed no desensitization. Thus, the UGR is composed of two BSM patterns: an initial single burst, termed urethrobulbospongiosus (UBS) reflex and a subsequent multiple bursting pattern (termed ejaculation-like response, ELR) that was only induced with penile clamping urethral occlusion. Transection of the SbPN eliminated the ELR in the penile clamping model, but the single UBS reflex remained in both the clamping and extension models. Pelvic nerve (PelN) transection increased the threshold for inducing BSM activation with both methods of occlusion but actually unmasked an ELR in the penile extension method. Hypogastric nerve (HgN) cuts did not significantly alter any parameter. Transection of all three nerves eliminated BSM activation completely. In conclusion, penile clamping occlusion recruits penile and urethral primary afferent fibers that are necessary for an ELR. Urethral distension without significant penile afferent activation recruits urethral primary afferent fibers carried in either the pelvic or pudendal nerve that are necessary for the single-burst UBS reflex.

[Dynamics of proliferation and apoptosis in the human bulbourethral glands in the process of aging].

The dynamics of the processes of proliferation and apoptosis in the epithelium of the bulbourethral glands in men aged 17-90 years was studied using monoclonal antibodies against PCNA and p53. Higher levels of cell reproduction and cell death were noted in the glandular duct epithelium as compared to those in secretory portions. Age-related increase in apoptosis which correlated with the activation of the glandular cell proliferation was shown. In old men, apoptosis in the bulbourethral glands was accompanied by the tendency to reduced cell proliferation. The correlation between the processes of cell reproduction and cell death in the epithelium of the bulbourethral glands, as well as their dependence on blood androgen levels, are discussed.

A neglected gland: a review of Cowper's gland.

Cowper's glands are pea sized glands present inferior to the prostate gland in the male reproductive system. They produce thick clear mucus prior to ejaculation that drains into the spongy urethra. Though it is well established that the function of the Cowper's gland secretions is to neutralize traces of acidic urine in the urethra, knowledge regarding the various lesions and associated complications of this gland is scarce. This review provides a comprehensive report on the development, function and various lesions associated with Cowper's gland.

Vaccination of boars with a GnRH vaccine (Improvac) eliminates boar taint and increases growth performance.

Peri- and postpubertal boars accumulate substances (e.g., androstenone and skatole) in their fatty tissue that are responsible for boar taint in pork. The objective of this study was to assess the efficacy of a GnRH vaccine, Improvac, in eliminating boar taint. Three hundred male (200 intact boars, 100 barrows) crossbred (Large White x Landrace) pigs were used in a 2 x 3 factorially arranged experiment. The respective factors were sex group (barrows, boars treated with placebo, or boars treated with Improvac) and slaughter age (23 or 26 wk). Vaccines were administered 8 and 4 wk before slaughter. All Improvac-treated pigs exhibited anti-GnRH titers. Testes and bulbo-urethral gland weights in treated pigs were reduced by approximately 50% (P < 0.001) and serum testosterone levels were below 2 ng/mL in the majority of treated boars (94 and 92% across both age groups at 2 and 4 wk, respectively). Boar taint, as assessed by the concentration of androstenone and skatole in s.c. fat, was suppressed to low or undetectable levels in 100% of Improvac-treated boars. No Improvac-treated pigs had significant concentrations of either androstenone (> 1.0 microg/g) or skatole (> 0.20 microg/g). In contrast, 49.5% of placebo-treated controls had significant androstenone and 10.8% had significant skatole levels, resulting in 10% of the control boars with high concentrations of both compounds. The mean concentrations of taint compounds in the Improvac-treated pigs were not significantly different from those in barrows. Improvac-treated boars grew more rapidly (P = 0.051 and < 0.001 for pigs slaughtered at 23 and 26 wk of age, respectively) than control boars over the 4 wk after the secondary vaccination, possibly because of reduced sexual and aggressive activities. Compared with barrows, Improvac-treated boars were leaner and had superior feed conversion efficiency. The vaccine was well tolerated by the pigs, and no observable site reactions could be detected at the time of slaughter. Vaccination of boars with Improvac allows production of heavy boars with improved meat quality through prevention and control of boar taint.

[Cowper's gland: anatomic, physiological and pathological aspects]. / Glandes de Cowper: aspects anatomique, physiologique et pathologique.

Cowper's glands are small appendages of the male genital tract, that are sometimes observed on intravenous urography voiding films. They are involved in the immune defence of the genitourinary tract, play a role in fertility, and secrete many glycoproteins, including PSA. They can be visualized in the form of a duct image parallel to the urethra, sometimes associated with opacification of the gland on IVU. This image can be differentiated from a fistula, extravasation of contrast agent, urethral duplication, or an artefactual image, by the course parallel to the urethra, the upper limit not exceeding the urogenital diaphragm, and the position of the orifice. These glands can be affected by neoplastic, infectious, stone and especially cystic disease: syringocele. The physician should think of these glands in patients with unusual genitourinary symptoms in order not to miss disease of these organs, and to prescribe appropriate treatment.

Collection of seasonally spermatozoa-rich semen by electroejaculation of laboratory woodchucks (Marmota monax), with and without removal of bulbourethral glands.

Male woodchucks were subjected to electroejaculation during the early- or mid-breeding season by a commercial stimulator and rectal probe (1.3 x 13 cm, with longitudinal electrode strips on one side) with electrodes oriented ventrally. A study of the voltage and stimulation parameters at a probe depth of 4 to 9 cm suggested that a series of 15 to 75 3-sec pulses of 3 to 6 V each could result in ejaculation and collection of semen. Pulses of only 1 to 2 V frequently caused erection but not ejaculation. Trials conducted on 12 bulbourethral (Cowper's) gland-intact males (n = 18 trials) versus six males from which Cowper's glands had been surgically removed (n = 18 trials) identified these glands as the source of urethral plugs in 77% of ejaculates from the gland-intact males and presumably the source of copulation plugs obtained from the vagina of female woodchucks. The fluid portion of ejaculates from both groups contained few or no spermatozoa. An additional 32 trials were conducted on 12 gland-intact males and eight males without Cowper's glands. These trials included 16 shallow (5 to 8 cm) versus 16 deep (10 to 13 cm) placements of the tip of the rectal probe in each group of males. In gland-intact males the stimulation of sacral (shallow) elements routinely resulted in the emission of large (200 to 300 microl) urethral plugs and fluid volume of 40 to 400 microl, containing few or no spermatozoa. In males without Cowper's glands the sacral stimulation typically produced volumes of 60 to 350 microl of noncoagulating liquid without urethral plugs, containing few or no spermatozoa. Lumbar (deep) stimulation in both groups of males usually resulted in fluid ejaculates, with 60% containing numerous spermatozoa (typically, 0.5 to 3 x 10(6)/ejaculate). Lumbar stimulation usually produced urethral plugs of little (50 to 100 microl) or no volume in gland-intact males and no urethral plugs in males without Cowper's glands. Ejaculates did not coagulate during handling or storage for 4 to 24 h. Serial lumbar stimulation of six males at 2- to 3-week intervals resulted in few spermatozoa, except for a 4- to 8-week period during which > or =0.25 x 10(6) spermatozoa/ejaculate and peaks of 5.3 +/- 2.4 x 10(6) spermatozoa/ejaculate were obtained. The results suggest that electroejaculation can be used to obtain spermatozoa-containing liquid that might be useful for semen evaluation or artificial insemination in laboratory woodchucks, that Cowper's glands are the source of urethral plugs in the ejaculates of this species, and that the fertile period of the male breeding season is limited to 4 to 8 weeks.

Evaluation of some reproductive parameters in the indigenous boar of Zimbabwe.

A number of reproductive parameters were evaluated in 12 adult indigenous boars. The seminal vesicles, prostate and bulbourethral glands had masses of 184.41 +/- 18.00 g, 16.69 +/- 2.42 g and 142.05 +/- 16.12 g, respectively, while the penile length measured 45.71 +/- 4.49 cm. The testes and epididymides had masses of 211.82 +/- 26.74 g and 108.81 +/- 11.49 g. The number of sperm averaged 2.78 +/- 0.59 x 10(9) in the testes and 11.76 +/- 2.11 x 10(9) in the epididymides. The daily sperm production per gram (DSPG) of testicular tissue and the daily sperm production rate (DSP) were calculated to be 2.98 +/- 0.31 x 10(6) and 0.62 +/- 0.14 x 10(9) spermatozoa, respectively. The serum level of testosterone measured 11.98 +/- 0.81 ng/ml. These values suggest a reduced reproductive capacity in these animals. However, appropriate selection techniques may be evolved to upgrade this indigenous stock while nutrition and management may be improved to increase body size, and hence, gonadal development.

Effect of mesenchymal glandular inductors on the growth and cytodifferentiation of neonatal mouse seminal vesicle epithelium.

To investigate the developmental properties of glandular mesenchymal inductors along the cranial-caudal extent of the developing male urogenital tract, neonatal mouse seminal vesicle epithelium (SVE) was combined with mesenchyme of the seminal vesicle (SVM), urogenital sinus (UGM), bulbourethral gland (BUG-M), or bladder (BLM) and grafted under the renal capsule of adult syngeneic or athymic male mice. Both SVM + SVE and UGM + SVE tissue recombinants expressed SV histogenesis and SV secretory proteins. BUG-M + SVE recombinants exhibited extensive growth as evidenced by a 36-fold increase in wet weight and a 27-fold increase in DNA content; however, the glandular structures that were induced in the SVE lacked the convoluted mucosa typical of SV. Furthermore, neither SV nor prostatic secretory proteins were detected in these recombinants. SVE grown in association with BLM failed to develop altogether. Thus, the ability to promote SV histogenesis and function is distinctly different in mesenchyme of cranial (SVM and UGM) versus caudal (BUG-M) regions. This implies the existence of a glandular inductive field in the developing male urogenital tract within which inductive activity varies regionally.

Ultrasonographic measurement of stallion accessory sex glands and excurrent ducts during seminal emission and ejaculation.

Accessory sex gland and excurrent duct activity of 10 stallions was visualized with transrectal ultrasonography during seminal emission and ejaculation. First and last penile urethral contractions were defined as the start (0 sec) and end of ejaculation, respectively. Duration of ejaculation (n = 63 ejaculations) averaged 6.15 +/- 2.98 sec. Penile urethral contractions occurred an average of 6.2 +/- 2.2 times per ejaculation. Right bulbourethral glands (n = 19 ejaculations) alternated repeatedly from ovoid to flattened, irregular shapes during ejaculation. Cross-sectional area of right bulbourethral glands did not change (p > 0.40) between 3 sec before ejaculation and the end of ejaculation. Cross-sectional area of right prostatic lobes (n = 17 ejaculations) decreased (p < 0.01) between 3 sec before ejaculation and the end of ejaculation, with decreases (p < 0.05) at 2, 1, and 0 sec before ejaculation and at the time of the second penile urethral contraction. Excurrent ducts of ampullae (n = 17 ejaculations) first appeared to dilate with fluid at 2.60 +/- 0.23 sec before ejaculation and subsequently dilated an average of 3.4 +/- 0.3 times between 3 sec before ejaculation and the end of ejaculation. Fifty-three of 58 (93%) ampullar duct dilations occurred prior to the start of ejaculation. During each dilation of ampullar ducts, fluid remained visible for 0.23 +/- 0.04 sec. Fluid was detected within the lumina of vesicular gland excurrent ducts during the 6 of 17 monitored ejaculations that produced detectable gel.(ABSTRACT TRUNCATED AT 250 WORDS)

Diffuse lymphoid tissue associated with the human bulbourethral gland. An immunohistologic characterization.

This study investigates the presence and distribution of immunocompetent cells in bulbourethral glands obtained from four multiorgan transplant donors. Monoclonal antibodies reacting with B (Leu 12+) and T (Leu 4+) cells, suppressor-cytotoxic cells (Leu 2+), helper-inducer (Leu 3a+) and natural killer (Leu7+) phenotypes, monocyte-macrophages, (LeuM3+), and cells expressing interleukin-2 receptor and HLA-DR antigen were tested in all specimens using an indirect immunoperoxidase staining procedure. T lymphocytes were estimated to represent 10% of the mucosal cell population. Almost all intraepithelial lymphocytes were suppressor-cytotoxic (CD8+) cells. The results demonstrate the presence of a defined distribution of immunocompetent cells in these sex accessory glands. Their role in combatting infections or other chronic genitourinary diseases is still undefined.

Immune response to parasitic infection in mice without seminal vesicles.

A protracted depression of anti-parasitic antibody and DTH responses were observed in Balb/c mice after surgical extirpation of seminal vesicles and ulterior infection with Taenia crassiceps cysts. Inclusion of male seminal accessory glands into the network of immunogonadal interactions was proposed.

Reproductive biology of the male bent-winged bat, Miniopterus schreibersii (Vespertilionidae) in southeast South Australia.

The seasonal chronology of the events of the reproductive cycle, and changes in the structure and function of the primary and accessory organs of the male bent-winged bat, Miniopterus schreibersii, were studied at latitude 37 degrees S in temperate southeastern Australia. The testicular cycle commenced in late spring (November), and sperm appeared in the seminiferous tubules and epididymides in early fall (March). The cycle of the accessory sex gland complex generally paralleled the testicular cycle, reaching maximum hypertrophy at the time of insemination in late fall (April/May). Thereafter, the primary and secondary sex glands (except the ampullary gland) involuted as the animals entered winter torpor. However, a cauda epididymal store of sperm persisted until late spring, and sperm were often observed, as well, in the ampullary gland duct and alveoli throughout winter. This study has confirmed that male Miniopterus differs from other vespertilionids in that accessory gland activity declines following the fall breeding in keeping with the fact that, unlike in other vespertilionids, insemination, ovulation and conception are concurrent events in the fall in this species. The reduced secretory status of the Leydig cells and exceptionally low levels of circulating androgens throughout the year, in combination with the presence of viable epididymidal sperm for most of gestation, are all interesting features of this reproductive cycle.

O tempo de latência do reflexo bulbo-cavernoso em sujeitos com ejaculaçäo prematura / Latency period of the bulbocavernous reflex in patients with premature ejaculation

Numa série de 10 pacientes consecutivos que se submeteram à investigaçäo por ejaculaçäo prematura, e nos quais foi realizada a eletromiografia do arco reflexo sacral-reflexo bulbo cavernoso-encontramos um tempo de latência aumentado estatisticamente significativo em relaçäo a um grupo padräo