Analysis of the contractions evoked by sympathetic nerve stimulation, and thermal effect on the guinea-pig vas deferens--study as a model for the thermotherapy of benign prostatic hyperplasia

BACKGROUND: The present study was designed to investigate the mechanism of thermotherapy on benign prostatic hyperplasia (BPH), using the guinea-pig vas deferens as a model for BPH. The components of contractions elicited by electrical field stimulation and nicotine were analyzed, and the thermal effect on the vas deferens was examined. METHODS: The vas deferens was dissected, suspended vertically through two silver ring electrodes, and attached to an isometric transducer. The electrical stimulation of 10 constant current pulses (10 mA) with 0.3 msec in duration of 5, 10, and 40 Hz was achieved under air-gap condition. Drugs were added directly to a 5 ml Magnus tube containing Tyrode solution (36 degrees C) gassed with a 95% O2-5% CO2 mixture. The components of contractions evoked by electrical stimulation and nicotine were investigated by tetrodotoxin (TTX), and blocking agents of alpha 1-adrenoceptors and/or purinoceptors. Thermal effect on electrically evoked contractions was examined at incubation temperature of 25 degrees C (control), 43 degrees C, 45 degrees C, 46 degrees C and 47 degrees C for 1 hour. RESULTS: Nicotine (200 microM) elicited biphasic contractions, which were triggered by corelease of noradrenaline (NA) and ATP (N-ATP) from sympathetic nerve terminals by activation of prejunctional nicotine receptors. NA and N-ATP caused the corresponding contractions, alpha 1 and N-ATP components, respectively. Combined application of prazosin (1 microM) and suramin (50 microM) abolished these contractions. Activation of post-junctional alpha 1-adrenoceptors by NA caused release of ATP from muscle cells to produce the contraction (alpha 1-ATP component), which was sensitive to both suramin and prazosin. N-ATP and alpha 1 components attributed to fast and slow part of the contraction, respectively. Electrical field stimulation caused biphasic contractions which consisted of both neurogenic (TTX-sensitive) and non-neurogenic (TTX-insensitive) components. An increase in stimulation frequency (5 to 40 Hz) increased the neurogenic components, which contained alpha 1 and N-ATP components, as well as the case of nicotine. The non-neurogenic components consisted of alpha 1-ATP, muscle-derived ATP (m-ATP) and unknown substance 'X' components. Nifedipine (10 microM). L-type Ca2+ channel blocker, markedly reduced the contractions induced by bath applied phenylephrine (alpha 1-agonist, 100 microM) but only partially blocked the contractions produced by bath applied ATP (500 microM). The contractile force in amplitude and neurogenic components induced by electrical field stimulation did not change at 43 degrees C, but both declined significantly above 45 degrees C. The neurogenic components at 45 degrees C and 46 degrees C were suppressed to 22 +/- 6% and 14 +/- 3% (mean +/- SD) of control, respectively. All the contractile responses were abolished at 47 degrees C. CONCLUSION: The contractions of the guinea-pig vas deferens evoked by electrical field stimulation consisted of alpha 1, N-ATP, alpha 1-ATP, m-ATP and X components. Sympathetic nerve fibers in the muscles were completely inactivated by thermal exposure at 47 degrees C for 1 hour. The results suggest that the minimal temperature for thermotherapy of BPH should be 47 degrees C.     

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.     

Effects of the antidepressant St. John's wort (Hypericum perforatum) on rat and human vas deferens contractility

PURPOSE: Since sexual dysfunction related to vas deferens smooth muscle contractility is a possible side effect of St. John's wort (SJW) (Hypericum perforatum) we evaluated the effect of this herbal antidepressant on rat and human vas deferens contractility. MATERIALS AND METHODS: The effect of SJW was evaluated on contractions induced by electrical field stimulation or exogenous agonists (alpha,beta-methylene adenosine triphosphate and phenylephrine) in isolated rat and human vas deferens. RESULTS: SJW (1 to 300 microM) decreased in a concentration dependent manner the amplitude of electrical field stimulation and agonist induced contractions with the same potency, suggesting direct inhibition of rat vas deferens smooth muscle. Of the chemical constituents of SJW tested hyperforin but not hypericin or the flavonoids quercitrin, rutin and kaempferol inhibited phenylephrine induced contractions. SJW and hyperforin also inhibited phenylephrine induced contractions in human vas deferens CONCLUSIONS: The results of our study demonstrate that SJW directly inhibits rat and human vas deferens contractility. If confirmed in vivo, these results suggest that SJW might affect sexual function in humans. These results might explain delayed ejaculation described in patients receiving SJW.     

Stimulating and potentiating effects of sodium nitroprusside on the guinea-pig vas deferens and their comparison with the effects on the portal vein and the taenia coli

The effects of sodium nitroprusside on the electrical and mechanical properties of the guinea-pig vas deferens were studied and compared with those on the portal vein and the taenia coli. Sodium nitroprusside at concentrations higher than 0.5 mM caused depolarization of the membrane of the vas deferens and initiated spontaneous contractions, while spontaneous contractions of the portal vein were blocked by similar concentration of the drug. Noradrenaline- and carbachol-induced contractions of the vas deferens were markedly potentiated by sodium nitroprusside, whereas the noradrenaline-induced contraction of the portal vein was suppressed by the same concentration of the drug. Increasing the K+ concentration by 15 to 30 mM caused a similar potentiation of the contraction by noradrenaline or carbachol in the vas deferens. When sodium nitroprusside was applied during the course of noradrenaline- or carbachol-induced contracture, contraction was observed in the vas deferens, while relaxation was induced in the portal vein and taenia coli. In either case, however, the addition of Ca caused a relaxation of the preparations. These results suggest that the membrane depolarization may be involved in the stimulating effects sodium nitroprusside in the guinea-pig vas deferens.     

Immunoreactive arginine vasopressin (AVP) and effects of AVP in the human vas deferens

Immunoreactive (IR) arginine vasopressin (AVP) was found to occur in the epididymal part of the human vas deferens. Segments from nine different subjects all contained IR-AVP in concentrations ranging from 37 to 717 fmol/gm. wet weight, concentrations severalfold higher than those normally found in the circulation. IR-AVP was shown by high performance liquid chromatography to elute in the same position as synthetic AVP. AVP added to isolated preparations of the human vas deferens induced concentration-related repetitive phasic contractions without significant changes of baseline tension. These contractions seemed to be mediated via stimulation of vasopressin V1-receptors and were abolished in the presence of vasopressin antagonists. Contractions induced by electrical field stimulation were frequency-dependent and sensitive to tetrodotoxin and prazosin. They were not affected by the vasopressin antagonists used. AVP increased the response to electrical field stimulation and this effect was inhibited by vasopressin antagonists. The results suggest either that circulating AVP is taken up and accumulated by the human vas deferens, and/or that AVP is synthesized locally. They do not suggest co-release of AVP and noradrenaline from nerve endings. The physiological role of the AVP occurring in the human vas deferens remains to be established.     

Possible role of sildenafil in inhibiting rat vas deferens contractions by influencing the purinergic system

AIM: To evaluate the effect of sildenafil, a selective inhibitor of cyclic guanosine monophosphate (cGMP)-selective type 5 phosphodiesterase, on isolated rat vas deferens and its connections with the purinergic system. METHODS: Epididymal and prostatic portions of isolated vas deferens were placed in organ baths containing Krebs' solution. Contractions were induced by noradrenaline (NA), adenosine triphosphate (ATP), alpha,beta-methylene ATP and electrical field stimulation (EFS). The effect of sildenafil on the contractions was compared with suramin and Evans blue (EB). RESULTS: NA, ATP, alpha,beta-methylene ATP and EFS caused contractions in both portions of vas deferens. NA-induced contractions were unaffected by sildenafil and suramin but potentiated by EB. ATP-induced contractions were non-competitively inhibited in both portions by sildenafil and suramin but potentiated by EB. alpha,beta-methylene ATP-induced contractions were unaffected by sildenafil but were inhibited in both portions by suramin and EB. EFS-induced contractions were inhibited by sildenafil and suramin while potentiated by EB. CONCLUSION: Sildenafil inhibited the contractions in both portions of vas deferens, as did suramin. We have suggested that purinergic system has a role in this antagonism and it seems to be mediated by an ATP-dependent mechanism instead of a receptor interaction.     

Seminal emission by electrical stimulation of the spermatic nerve and epididymis

The spermatic nerve and epididymis were stimulated electrically in dogs to elucidate the possibility of artificial seminal emission after bilateral transection of the hypogastric nerves and sympathetic trunks. Before transection, electrical stimulation of a distal end of the severed spermatic nerve caused a trace amount of emission in two dogs and no emission in the remaining four. In contrast, 1 month after the transection, stimulation of a distal end of the severed spermatic nerve caused seminal emission in all six dogs examined, with full seminal volume in four dogs and partial volume in the remaining two. Anatomically, sympathetic nerves originating from the upper portion of the lumbar sympathetic ganglia descended along the spermatic arteries to the testes as spermatic nerves. The present results indicate that spermatic nerves have the potential to generate seminal emission as a compensatory pathway after bilateral transection of the hypogastric nerves. Both direct and percutaneous electrical stimulation of epididymal tails resulted in a full volume of seminal emission in all dogs with transection of both hypogastric nerves and lumbosacral sympathetic trunks as well as in unoperated controls, while high voltage (8 V vs 40-80 V) was required to cause seminal emission by electrical stimulation on the skin surface. Direct stimulation of epididymal tails in men undergoing orchidectomy as treatment for prostatic carcinoma or during biopsy of the contralateral testis in a patient with a testicular tumour, resulted in seminal emission in all five epididymides examined either from the end of the severed vas deferens or in the posterior urethra if the vas deferens was not severed.     

Long-term use of sertraline leads to alterations in contractility of rat isolated vas deferens

Previous experiments with rat isolated vas deferens have shown that sertraline pretreatment inhibits contractile responses to noradrenaline, KCl, serotonin and electrical field stimulation. In the present study, the aim was to investigate the effects of long-term use of sertraline on contractile responses of rat isolated vas deferens. Fifteen Sprague-Dawley rats were given long-term (21 days) sertraline treatment, while another 15 were used as control. Both vas deferens were excised. Epididymal and prostatic segments of each underwent electrical field and chemical stimulation (noradrenaline, serotonin, acetylcholine, adenosine-triphosphate). Epididymal and prostatic segments had different contraction characteristics. Long-term sertraline treatment inhibited contractile responses of vas deferens segments to electrical field stimulation. The responses to noradrenaline were amplified with a left shift on both segments. Responses to serotonin had only a left shift on epididymal segments, while no contractile responses were observed on prostatic segments of the groups. Long-term treatment with sertraline had peripheral effects on rat vas deferens contractility, and some of the effects may be through mechanisms other than the inhibition of serotonin re-uptake.     

Effects of the high K+/Na+ deficient solution on mechanical response and wet weight of tissue in vas deferens and seminal vesicle in guinea-pig

In the present experiments, we investigated contractions of guinea-pig vas deferens or seminal vesicle in various kinds of high K+ solution. The vas deferens showed a phasic contraction followed by a tonic one in hyperosmotic 65 mM KCl (hyper-65K+), isosmotic 60 mM or 120 mM KCl solution. However, isosmotic 154 mM KCl (iso-154K+) solution induced a large phasic contraction followed by a gradual relaxation. Applications of the high K+ solutions to the preparation of seminal vesicle showed almost similar results in tension to those of the vas deferens. In the vas deferens or seminal vesicle, an application of hyper-65K+ solution significantly decreased the relative value for the wet weight of the tissue at 120 min, but that of iso-154K+ solution did not affect the wet weight of both the muscles. In the vas deferens, an hyperosmotic addition of sucrose at a concentration of 25 to 100 mM slightly prevented the tension decreased by the iso-154K+ solution and slightly decreased the relative wet weight. In the seminal vesicle, increasing sucrose concentration significantly increased the tension, but decreased the relative wet weight. In both the muscles of vas deferens and seminal vesicle, an addition of pyrvate or oxalacetate (5.5 mM) to the iso-154K+ solution without glucose maintained the muscle tension at a maximal level in the iso-154K+ solution with glucose for 120 min. Further, the tension decrease in both the muscles induced by iso-154K+ solution was also prevented by hyperosmotic application of NaCl. From these results, it is suggested that the tension decrease by high K+, Na+-deficient solution in the vas deferens is mainly caused by an inhibition of glucose utilization by Na+-deficiency in the medium, however, the seminal vesicle is probably due to the cell swelling and partly the inhibition of glucose utilization by it.     

Glandular inclusions in inguinal hernia sacs: morphologic and immunohistochemical distinction from epididymis and vas deferens

Glandular inclusions in inguinal hernia sacs may bear a striking resemblance to the epididymis or vas deferens. Misinterpretation as a transected functional structure may raise significant concerns regarding reproductive capability, even if encountered unilaterally. In a child, resolution of these concerns may be years away with the onset of puberty and documentation of normal sperm counts. CD10 has been shown to be present in Wolffian-type epithelium and to be absent in Mullerian-type epithelium. We hypothesized that an antibody to CD10 would react with vas deferens and epididymis and fail to react with hernia sac inclusions, most of which we thought were Mullerian duct-derived structures. Glandular inclusions in 29 hernia sacs from prepubertal males were classified histologically according to their resemblance to normal structures and analyzed for CD10 by immunohistochemistry. Inclusions resembling vas deferens had their external diameters measured and were also stained for smooth muscle actin. Thirty-one examples of normal vas deferens and 13 examples of normal epididymis were included for comparison. The inclusions were classified as vas deferens-like (9), epididymis-like (13), and Mullerian-like (7). CD10 reactivity was lacking in all vas deferens-like inclusions; their median external diameter was 0.6 mm. Of the epididymis-like inclusions, 7 of 13 were CD10 positive. The CD10-negative cases consisted of glands with well-defined stromal coats distinct from adjacent stromal coats. CD10-positive cases were more numerous, more tightly aggregated, and surrounded by less well-developed stromal coats that blended with adjacent coats. All seven Mullerian-like remnants were CD10 negative. All normal vas deferens and epididymis showed at least focal CD10 reactivity. CD10 positivity in all cases had a luminal membranous staining pattern. Both the vas deferens-like inclusions and the normal vas deferens showed strong smooth muscle actin positivity in their stromal coats. CD10 negativity and external diameter <1 mm are highly useful to distinguish vas deferens-like inclusions from true vas deferens. Epididymis-like inclusions are more problematic. Some react for CD10 and may represent aberrant Wolffian ductules. Others are CD10 negative, distinct from true epididymis, and may be of Mullerian differentiation. Mullerian-like remnants can be diagnosed on the basis of their limited number and scattered distribution. Lack of CD10 immunostaining corroborates this interpretation.     

Inhibitory effect of serotonergic drugs on contractile response of the rat vas deferens to electrical nerve stimulation: in vivo study

PURPOSE: To evaluate, in vivo, the inhibitory effects of certain serotonergic drugs on the contractile response of the rat seminal tract to electrical stimulation of the hypogastric nerve. MATERIALS AND METHODS: Twenty-five Sprague Dawley rats (250 to 300 gm. each) were equally divided into 5 groups based on experimental agent; normal saline, clomipramine, sertraline, paroxetine, and fluoxetine. The hypogastric nerve was electrically stimulated and the intraluminal pressure of the vas deferens was measured, both pretreatment and 30 minutes after intravenous injection of four different doses (0.1 to 20 x the therapeutic dose) of each agent. Variations of responses relative to the time after administration of each agent (at 10- and 20-fold concentration) were also observed. RESULTS: All serotonergic drugs caused dose-dependent inhibition of elevation in intraluminal pressure of the vas deferens (p <0.05). The inhibitory effect of clomipramine was significantly better (p <0. 05) than that of fluoxetine at a 1-fold dose, while no significant differences were noted among clomipramine, sertraline and paroxetine. At doses of 10- and 20-fold, clomipramine had the strongest inhibitory effect, followed by sertraline and paroxetine, then fluoxetine (p <0.05). No differences were found in the inhibitory effects of the drugs studied, as a function of the time after injection. CONCLUSIONS: Clomipramine was the most potent drug for inhibition of elevation in intraluminal pressure of the rat vas deferens induced by electrical stimulation of the rat hypogastric nerve. The stronger inhibitory effect of clomipramine than the selective serotonin reuptake blockers suggests a possible peripheral action of clomipramine in addition to its central serotonergic action.     

Comparative effects of T‐type and L‐type Ca2+‐antagonists against noradrenaline‐induced contractions of human vas deferens

OBJECTIVE

To investigate the effects of the relatively selective T‐type Ca²⁺‐antagonists, mibefradil and flunarizine, and the L‐type Ca²⁺‐antagonist, nifedipine, on the contractions of longitudinal and circular muscles of human vas deferens, to elucidate the possible involvement of T‐type voltage‐gated Ca²⁺ channels (VOCs) in the contractile function of the tissue.

MATERIALS AND METHODS

Human vas deferens specimens from elective vasectomies were cut into strips of longitudinal muscle or transversely into rings of circular muscle. These were set up for tension recording and superfused with Krebs’ medium (36° C). Contractions were evoked by noradrenaline or high [K⁺]_o (in the presence of the L‐type Ca²⁺ agonist, FPL 64176) and the effects of Ca²⁺ antagonists were determined.

RESULTS

Noradrenaline (0.1–100 µmol/L) evoked rhythmic and tonic contractions of longitudinal and circular muscles, which were potently inhibited by nifedipine (≤0.1 µmol/L). Mibefradil (1–10 µmol/L) inhibited the contractions but was comparatively more effective in longitudinal than circular muscle. Flunarizine was ineffective except against contractions to low concentrations of noradrenaline. The drugs’ potencies as antagonists of L‐type VOCs were determined against contractions to high K⁺ (120 mmol/L in the presence of FPL 64176, 1 µmol/L). The contractions in longitudinal and circular muscle had different times to peak and decline but were inhibited comparably by nifedipine (50% inhibitory concentration, IC₅₀, longitudinal and circular muscle, ≈2 nmol/L) or by mibefradil (IC₅₀ longitudinal muscle, 1.1 µmol/L; circular muscle, 2.4 µmol/L) and were less sensitive to flunarizine (up to 30 µmol/L).

CONCLUSION

These results indicate that noradrenaline‐induced contractions of human vas deferens depend primarily on nifedipine‐sensitive L‐type VOCs, as opposed to mibefradil/flunarizine‐sensitive T‐type VOCs. The effects of mibefradil and flunarizine, at concentrations found to be effective against noradrenaline‐induced contractions, involve the blockade of L‐type VOCs. The modest differential effect of mibefradil in longitudinal and circular muscle is discussed in relation to factors that modulate activation and drug‐sensitivity of L‐type VOCs.     

Analysis of spermatozoa from the proximal vas deferens of fertile men

Fluids from the left and right proximal vas deferens were collected from 105 normal fertile men by cannulating the vas deferens during vasectomy, and sperm parameters analysed. Sperm motility (73.1 k 13.3Y0), normal sperm morphology (75.2 k 11.1"/o), sperm viability (72.7 k 18.8%) and the hypo-osmotic swelling test (73.3 k 19.2%) were in the normal range, compared with that of ejaculated spermatozoa. However, sperm Concentration in the proximal vas deferens (6274.6 k 5103.8 × 10" ml^-' was higher than that in semen. Sperm concentration in the right vas deferens was significantly higher (P<0.05) than that in the left and the percentage of spermatozoa showing abnormal cervical mucus penetration was Significantly higher (47%) for the left than for the right (18%). There were no anti-sperm antibodies on the surface of spermatozoa from the vas deferens as determined by the sperm cervical mucus contact test and immuno bead test. These parameters of spermatozoa from the proximal vas may reflect those of spermatozoa from the human cauda epididymis.     

The actions of extracellular magnesium on isolated human detrusor muscle function.

The effects of increasing the extracellular magnesium concentration ([Mg]) on the in vitro mechanical and electrophysiological properties of isolated human detrusor smooth muscle have been investigated. Raising extracellular Mg reduced the magnitude of the electrically-induced phasic contractions as well as spontaneous contractions. A similar increase in the [Mg] reduced the magnitude of the inward Ca2+ current associated with the action potential as well as shifting the activation curve to more positive potentials. Spontaneous oscillations of intracellular Ca2+ could be observed in some isolated cells and such activity was also abolished by raising the extracellular [Mg]. It is proposed that the contractile effects of raised extracellular Mg are mediated by an action on the inward Ca2+ current and that these observations suggest a means whereby normal and abnormal detrusor contractions might be effectively regulated.     

Immunocytochemical localization of the Ya, Yb1, Yc, Yf, and Yo subunits of glutathione S-transferases in the cauda epididymidis and vas deferens of adult rats

Glutathione S-transferases (GSTs) are dimeric proteins grouped into five classes based on the degree of amino acid homology of their subunits. They are involved in cellular detoxification through the catalyzation of the conjugation of reduced glutathione with various electrophilic substances. In the present study, the distribution of Ya and Yc subunits from the alpha family, Yb1 and Yo subunits of the mu class, and the Yf subunit of the pi class were examined with light microscope immunocytochemistry in Bouin-fixed, paraffin-embedded tissue of different regions of the cauda epididymidis and vas deferens. In the cauda, principal cells showed high levels of expression of Ya, Yc, and Yo subunits, while in the vas deferens, staining decreased to moderate levels for the Ya and Yo subunits and to low levels for the Yc subunit. While Yf was maintained at low levels in principal cells of all cauda and vas deferens regions, Yb1 expression was more erratic, presenting a checkerboard-like staining pattern in the proximal vas deferens and showing moderate cytoplasmic but intense nuclear reactivity in all other regions. Basal cells in the cauda were intensely reactive for Yf, while in the vas deferens, they became unreactive. Conversely, basal cells were unreactive for Ya in the cauda and proximal vas deferens, while in the middle and distal vas deferens, they became moderately reactive. In the case of Yb1 and Yo, some basal cells were reactive while others appeared unreactive in all cauda and vas deferens regions. Yc elicited the display of both reactive and unreactive basal cells in the cauda regions, and while the cells were moderately reactive in the proximal vas deferens, they became intensely reactive in the middle and distal vas deferens. In summary, both principal and basal cells show varying degrees of GST expression in the different regions of the cauda and vas deferens, suggesting that these cells are subjected to a complex, changing environment of substrates. Furthermore, while expression often differs from principal to basal cells, the absence of reactivity of a given GST in one cell type is usually compensated for by expression in the other cell type in any given region of the cauda or vas deferens. Taken together, the data suggest that ample protection from harmful circulating electrophiles can be provided for sperm during their storage in the cauda and vas deferens. In addition, since principal cells of the vas deferens are involved in steroid synthesis, the presence of GSTs in these cells may also serve to bind steroids, or this presence may be involved in steroid isomerization.     

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.     

急性热应激对性成熟雄性小鼠睾丸、附睾、输精管中热休克蛋白70表达的影响

目的:探讨急性热应激对性成熟雄性小鼠睾丸、附睾、输精管中热休克蛋白70(heat shock protein 70,HSP70)表达的影响。方法:将32只8周龄雄性小白鼠随机均分为4组,饲养7d后,进行热应激处理,温度控制在(39±0.5)℃,时间分别为0.5、1和3h。应激后立即采血,分离血清测定谷草转氨酶(GOT)含量。一侧附睾制备精子悬液,用于计算精子密度和顶体畸形率;另一侧附睾、睾丸、输精管用于免疫组化研究。结果:应激后,小鼠体重、睾丸系数、顶体畸形率变化不显著(P>0.05),附睾系数和精子密度有不同程度的下降,GOT含量急剧升高(P<0.01)。随着应激时间的延长,小鼠精子密度呈递减趋势,顶体畸形率呈上升趋势。应激时间最短的0.5h组小鼠体重、睾丸系数、附睾系数的降幅反而最大。免疫组化法观察发现,HSP70在性成熟小鼠睾丸、附睾、输精管中均有表达。正常状态下,HSP70在睾丸组织间质细胞中少量表达,应激后分布于间质细胞核,此外在精母细胞核与精子细胞核中也有大量分布;附睾中HSP70主要分布于主细胞质,基细胞和亮细胞中没有表达,应激后附睾体的纤毛细胞中也发现大量棕色颗粒;输精管中HSP70主要定位在基细胞质,主细胞中不表达。随着应激时间的延长,HSP70在睾丸、附睾中的表达量明显升高,而在输精管中的增幅不明显。结论:急性热应激对性成熟雄性小鼠的生殖系统造成了损伤;HSP70在睾丸、附睾、输精管中的表达与定位具有区域特异性和细胞特异性,提示其可能参与精子的发生与成熟;HSP70在应激状态下表达量大幅上升的作用可能在于保护细胞免受高热损伤。     

输精管激光凝堵绝育术临床应用研究

目的探索氩离子(Ar^ )激光凝堵人类输精管的作用机制,观察临床应用效果。方法62名成年已婚且有2—3个子女的健康男性志愿者为研究对象,采用Ar^ 激光照射的方法进行输精管凝堵。对前4例受试对象切开阴囊皮肤,直视下进行激光照射,其余58例受试对象经皮穿刺进行体内照射。通过精液化验,观察精子减少速度及消失时间。结果60例受试对象被照射6个月后精子数减为0,2例因照射剂量不足而失败。结论Ar^ 激光是用于输精管凝堵的较为理想的光源之一,能较好地凝堵输精管且基本无并发症和后遗症。     

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.     

Repeated vas occlusion and non-invasive reversal with styrene maleic anhydride for male contraception in langur monkeys

The feasibility of a spacing method for contraception, using Styrene Maleic Anhydride (SMA) as a vas occlusive agent, has been assessed in male langur monkeys. The vas deferens of 6 animals were occluded with 60 mg SMA in 120 microL DMSO. After 150 days, the occlusion was reversed by a technique which involved palpation, percutaneous electrical stimulation, forced vibratory movement, suprapubic percussion and per-rectal digital massage of the vas segments. The vas deferens were then re-occluded with SMA and reversed by the non-invasive method after three consecutive azoospermic samples. The second vas occlusion resulted in uniform azoospermia after the third ejaculation and reversal caused the reappearance of spermatozoa in the semen to severe oligozoospermic levels in the first two ejaculations and rising to normospermia in the subsequent ejaculations. Ultrastructure of the spermatozoa by SEM and TEM and sperm function tests revealed that the spermatozoa had recovered normal morphology. Vas morphology also regained a normal pseudostratified columnar epithelium containing basal and principal cells. The results suggest that the SMA-based spacing technique for male contraception could be extrapolated to the human by use of no-scalpel injection and non-invasive reversal.