Interrelationships between androgens and prostaglandins in the vas deferens of prepubertal rats.

Prostaglandin (PG) levels in the genital tract of male rats were measured at different ages. The vas deferens contained the highest amounts of both PGE2 and PGF2 alpha in young adult or prepubertal animals. PGE2 content increased considerably with age. PGE2 alpha was high in younger animals but decreased markedly at 35 days of age and remained low thereafter. PGE2 and PGF2 alpha were reduced following bilateral castration or hypophysectomy. Testosterone propionate (TP) prevented the postoperative fall in PG levels in a dose-dependent manner. Differences were noted in the relationship between changes in organ weight or PGE2 and pge2 alpha content, and the dose of TP injected, the operation, the time of treatment, and the PG studied.     

Role of intracellular Ca2+ stores in smooth muscle contractions of the guinea pig vas deferens

Summary Guinea pig vas deferens was used as an animal model for alpha-1 adrenoceptor (₁-receptor) mediated contractions in human hyperplastic prostatic tissue. The selective ₁-receptor agonist, phenylephrine (PE), induced fully reversible, dose-dependent contractions antagonized by increasing concentrations of the ₁-receptor blockers prazosin (1–100 nM) and YM 617 (0.1–10 nM). Removal of extracellular Ca²⁺ reduced PE-evoked contractions in a time-dependent manner. Nifedipine (1–1000 nM), a blocker of voltage-dependent L-type Ca²⁺ channels (VDCC), inhibited the PE-induced response by up to 65%. Removal of extracellular Ca²⁺ abolished the ₁-agonist reactivity in a time-dependent fashion. To elucidate the participation of intracellular Ca²⁺ stores in ₁-receptor contractions, the tissue was pretreated with ryanodine (10 M) or thapsigargin (0.1 M), established inhibitors of Ca²⁺ release from intracellular pools. Both substances reduced the PE contractions by up to 80%. Nifedipine suppressed the remaining contractions completely. This provides evidence that Ca²⁺ influx through VDCC and Ca²⁺ release from intracellular stores contribute to ₁-receptor contractions in the guinea pig vas deferens and may be important in obstructive benign prostatic hyperplasia.     

先天性双侧输精管缺如患者睾丸超微结构的改变

目的 了解先天性双侧输精管缺如（Congenital bilateral absence of vas deferens,CBAVD)患者睾丸超微结构的改变,以预测单精子卵胞浆内注射（ICSI）治疗效果。方法 对13例光镜下睾丸组织形态学正常的CBAVD患者睾丸组织进行电镜观察。结果 曲细精管界膜改变表现变睾丸曲细精管基膜增厚,分层,向管腔形成不同程度的指状突起,基膜外胶原纤维呈不同程度增多,增粗、排列紊乱,极性消失,生精上皮表现为精子细胞头部畸形,胞核染色质呈现明显颗粒状结构。出现核内空泡,精子细胞中段线粒体鞘部分或完全缺失,顶体内陷,顶体囊增大,内有电子密度不高的片层结构（5例）。支持细胞表现数目增多,胞浆内脂质颗粒及降解小体明显增多。有时可见支持细胞之间的紧密连接消失（2例）。结论 CBAVD患者睾丸组织超微结构异常主要表现为界膜与精子细胞的改变,CBAVD所致的无精子症除了梗阻因素外,同时合并了睾丸性因素。     

Injury to the pre-pubertal vas deferens. I. Histological analysis of pre-pubertal human vas.

There is very little information in the literature on the development of the human vas deferens. Therefore, the age at which the pre- or para-pubertal vas deferens becomes large enough for a vasovasostomy to be technically feasible is unknown. To determine the age or degree of sexual maturity at which a microscopic vasovasostomy is technically feasible, we collected surgical or autopsy vasa from 34 young males over a three year period, and correlated vasal size to age and Tanner stage (degree of sexual maturity ranging from 1-childhood to 5-adult). The specimens were embedded and sectioned transversely in glycol methacrylate. Using image analysis, the total transverse area and diameter, and luminal area and diameter was determined for each specimen. Surprisingly, there was no change in vasal size from birth up through 11 years. From age 15 years and on, the vas was adult in size. The vas develops to adult size between Tanner stages 2 and 3. The average external and luminal diameters of pre-midpuberty specimens (Tanner stages 1 and 2) were 1.0 and 0.19 (mm.) and the diameters of post-midpuberty specimens were 2.1 and 0.43 (mm.), respectively. These results suggest that, in the event of a recognized iatrogenic injury to the vas deferens after midpuberty, a repair by a traditional microsurgical vasovasostomy is possible. If the vas is injured before midpuberty it may be technically difficult to repair by traditional microsurgical methods.     

Congenital absence of the vas deferens.

Fourteen personal cases of agenesia of the vas deferens, bilateral in 12 and unilateral in 2, are described. In 13 of the cases the diagnosis was confirmed by surgical exploration. In most of the cases cytologic examination of aspiration biopsy specimens and histologic examination of surgical specimens of the testes showed that spermatogenesis was normal. The appearance of biopsy specimens of the epididymides were normal except for a certain degree of interstitital fibrosis and dilation of the ductus epididymidis. Endeavours to produce an artificial spermatocele with the aid of an isolated flap of tunica vaginalis in several patients proved unsuccessful. In one patient with a naturally preformed spermatocele the latter was aspirated, and the patient's wife was inseminated with the cellular content from the aspirate. This procedure has been repeated on several occasions, but so far without any subsequent conception. The failure of treatment of these patients may perhaps be due to some change in the function of their epididymides. This possibility is discussed.     

Autoradiographic localization of tritium-labeled dihydrotestosterone in human vas deferens

The human vas deferens was examined autoradiographically for the presence and distribution of androgen receptors. Samples of vas deferens from the region proximal to the testis and the region at the internal inguinal ring were incubated in vitro with tritium-labeled dihydrotestosterone ([3H]-DHT). Frozen sections of tissue were mounted on autoradiographic emulsion-coated slides and exposed for up to three weeks to demonstrate cells with nuclear accumulations of radioactive hormone. Quantitation of autoradiograms was performed with a Zeiss Videoplan morphometric analysis system. Cells in all five tissue layers of the vas deferens were able to bind androgen receptors in the nucleus, as evidenced by superimposition of silver grains over the nuclei of cells in external, middle, and internal smooth muscle layers, as well as in epithelial and subepithelial stromal cells.     

Effect of histamine on human vas deferens in vitro

Histamine, 2-methylhistamine and 4-methylhistamine produced concentration-related contractions in some isolated human vas deferens preparations. The contractions produced by histamine and its analogues were reversibly and competitively antagonised by the H1-receptor blocker, mepyramine, but not the H2-receptor blockers, burimamide and cimetidine. Phentolamine, atropine and guanethidine did not affect the excitatory action of histamine. Histamine and 4-methylhistamine did not show any inhibitory effect on KCl-induced tone. The results showed that histamine receptors were present in the human vas deferens and the histamine receptors mediating the excitatory response were likely to be H1-receptors.     

Hormonal influence on the neurogenic response of the hamster vas deferens

The effect of castration on in vitro contractility of smooth muscle of the vas deferens and body of the bladder has been studied in the hamster. Castration produced supersensitivity to in vitro electrical stimulation and norepinephrine in the vas deferens, but had no effect on the body of the bladder. Castration also increased the maximum contractile response of the vas deferens to electrical stimulation, norepinephrine, ATP, acetylcholine and histamine. The changes in contractility of smooth muscle of the vas deferens developed slowly and may be explained by specific effects upon adrenergic and purinergic neurotransmission and/or non-specific effects upon smooth muscle cell membranes.     

Calcium channel blockade and contractile responses in the isolated human vas deferens

The effects of removal of extracellular calcium and of the calcium channel blockers nifedipine, verapamil and diltiazem were studied on contractions induced by electrical field stimulation and high K+-solution in isolated preparations of the human vas deferens. Electrically induced contractions were blocked by tetrodotoxin and alpha-adrenoceptor blockade. They were abolished in calcium-deficient medium, and suppressed by the calcium channel blockers in the order of potency nifedipine greater than verapamil greater than diltiazem. The maximum blocking effect of nifedipine was approximately 40%. All the blockers practically abolished K+-induced contractions. It is concluded that even if the contractile response of the human vas deferens to electrical stimulation is dependent on extracellular calcium, calcium channel blockers seem to have only a limited effect on this contraction and their capability of impairing the function of the vas deferens in patients is questioned.     

Agenesis or atrophy of the testis and vas deferens.

In this study the author examines the relationship between agenesis or atrophy of the testis and of the vas deferens. From a prospective study of 237 cases of unilateral and bilateral undescended testis, 12 cases of agenesis of a testis were seen; 9 of the 12 cases were associated with agenesis of the vas deferens and in 3 of these unilateral renal agenesis was also present, not necessarily ipsilaterally. Three other cases of testicular agenesis and four cases of extreme testicular atrophy were seen. In all seven, the vas deferens was present in part or in its entirety and roentgenography disclosed a normal upper urinary tract. Agenesis of the vas deferens was seen only in patients with monorchism. No patient was anorchid. It is concluded that an important link exists between agenesis of the vas deferens and agenesis of the testis.     

Laser irradiation of the guinea pig basilar membrane

BACKGROUND AND OBJECTIVES: The cochlea is the part of the inner ear that transduces sound waves into neural signals. The basilar membrane, a connective tissue sheet within the cochlea, is tonotopically tuned based on the spatial variation of its mass, stiffness, and damping. These biophysical properties are mainly defined by its constituent collagen fibers. We sought to assess the effect of laser irradiation on collagen within the basilar membrane using histological analysis. STUDY DESIGN/MATERIALS AND METHODS: Four excised guinea pig cochleae were stained with trypan blue. From these, two were irradiated with a 600 nm pulsed dye laser and two were used as controls. Collagen organization was visualized using polarization microscopy. RESULTS: Laser irradiation reduced the birefringence within the basilar membrane as well as within other stained collagen-containing structures. Larger reductions in birefringence were measured when more laser pulses were given. The effects were similar across all turns of each cochlea. CONCLUSIONS: Laser irradiation causes immediate alterations in collagen organization within the cochlea that can be visualized with polarization microscopy. These alterations may affect cochlear tuning. Ongoing research is aimed at analyzing the effect of laser irradiation on cochlear function. It is conceivable that this technique may have therapeutic benefits for patients with high-frequency sensorineural hearing loss.     

Age-related differences in norepinephrine and non-collagenous protein in human vas deferens

The existence of norepinephrine or non-collagenous protein in some tissues is believed to reflect the sympathetic discharge of the structures and plays an important role in contractile ability. Specimens of vas deferens were obtained from 44 subjects in various decades of life from age 20 to 84, and levels of norepinephrine, non-collagenous protein, collagen and elastin were determined. The level of norepinephrine and non-collagenous protein declined with increasing age. Both parameters inversely correlated with age. Collagen and elastin increased with advancing age. The regression line and coefficient of correlation between both variables showed significantly positive correlations. It is suggested that the contractile ability of human vas deferens, as defined by norepinephrine and non-collagenous protein contents, decreases with age, and the age-related increase in collagen and elastin may be of importance in reducing the contractile capability of this structure.