棉酚对大鼠睾丸组织环一磷酸腺苷含量的影响

棉酚抗生育作用的机理国内外已有不少研究报导。国内王振刚等曾观察到棉酚对大鼠血浆 cAMP(环一磷酸腺苷)和 cGMP(环一磷酸乌苷)没有影响;而睾丸组织 cAMP 含量增加。为此,我们采用大剂量醋酸棉酚和较长时间给药对大鼠睾丸组织 cAMP 含量进行研究。     

氚标记( )与(-)棉酚在大鼠主要脏器的亚细胞分布及共价结合

给大鼠腹腔及睾内注射氚标记的( )与(-)棉酚后第7、18天,对主要脏器中各亚细胞组分的总放射活性及共价结合的放射活性进行了动态观察。结果表明,(-)棉酚在心肌线粒体共价结合放射活性较明显高于( )棉酚;( )及(-)棉酚在睾丸细胞膜、微粒体共价结合的放射活性随时间增高,且(-)棉酚较为明显。     

氚标记(+)与(-)棉酚在大鼠主要脏器的亚细胞分布及共价结合

给大鼠腹腔及睾内注射氚标记的(+)与(-)棉酚后第7、18天,对主要脏器中各亚细胞组分的总放射活性及共价结合的放射活性进行了动态观察。结果表明,(-)棉酚在心肌线粒体共价结合放射活性较明显高于(+)棉酚;(+)及(-)棉酚在睾丸细胞膜、微粒体共价结合的放射活性随时间增高,且(-)棉酚较为明显。     

醋酸棉酚对幼龄大鼠睾丸间质细胞分泌活性及细胞膜表面LH/hCG受体发育的影响

醋酸棉酚有抗雄性生育作用,但对睾丸间质细胞的作用尚未取得一致意见。部分研究者观察到醋酸棉酚对睾丸间质细胞有抑制作用。本室也曾证明,服醋酸棉酚后,青春前期大鼠,睾丸间质细胞的生长发育及其类固醇激素合成酶的活性均受抑制。已有报告,睾丸间质细胞表面具有分子量为20万的LH/hCG受体,该受体的数量及活性决定了间质细胞睾酮分泌活性及对促激素的反应。此受体在大鼠五周龄前逐步发育完善,而在4周龄时已表现出对外源性LH/hCG敏感的反应性。本实验以幼龄大鼠为对象,用放射免疫测定及放射受体分析法研究了醋酸棉酚对睾丸间质细胞的影响。     

棉酚造成大鼠精子质量下降与NO之间关系的研究

目的阐明棉酚造成精子质量下降的生化机制,为其应用和降低毒副作用提供新思路。方法采用Wistar大鼠口服给予棉酚(50mg·kg-1/2d),2wk后取附睾尾精子,采用CASA进行检测,同时对血清中的促黄体生成素(LH),促卵泡生成素(FSH)、睾酮(T)进行检测,对睾丸组织形态学以及组织内的一氧化氮(NO)含量进行检测。结果棉酚可造成精子的数量减少,活力降低。睾丸组织内部结构紊乱,睾丸组织中的NO水平上升,血清中的T下降,而对FSH、LH无影响。化合物NA1108可拮抗棉酚造成的精子质量下降,降低睾丸内NO含量,升高血清中T含量。结论棉酚造成精子质量降低的机制之一是由于其造成睾丸组织内NO的过量产生,从而损伤睾丸组织内的多种细胞所致,能降低睾丸内NO含量的药物可提高精子质量。     

棉酚在大鼠附睾中的转运

用微灌流方法研究了棉酚在大白鼠附睾管尾端的转运情况。发现棉酚很难进入附睾液。用脂质体包埋棉酚也不能提高其转运率、讨论了棉酚在附睾与睾丸中的不同转运情况。设想血附睾与血睾屏障二者对物质的转运有所不同。     

醋酸棉酚对肝脏、睾丸和小肠等组织H~3-胸腺嘧啶核苷参入的影响

本文用H~3-胸腺嘧啶核苷参入法,观测了醋酸棉酚对肝脏、睾丸和小肠等组织DNA合成的影响,并与抗肿瘤药5Fu作了比较。结果表明棉酚没有类似5Fu的抑制DNA合成的作用。 醋酸棉酚(简称棉酚)为男用节育药,已在临床试用多年。但是少数服药者在服起效量期间,有胃肠道症状和一时性的转氨酶升高,是否和棉酚对肝脏和胃肠的损害有关,且有报道棉酚对某些肿瘤有疗效,其作用是否与烷化剂类似,棉酚抗生育作用在于抑制生精过程。是否通过抑制核酸合成代谢而起作用,如果干扰DNA合成是否可能影响遗传因子,研究棉酚对肝脏和睾丸组织的DNA合成代谢,有助于上述问题的阐明。     

口服棉酚者血清中睾丸酮、促黄体生成素和卵泡素浓度的变化

棉酚是一种作用干睾丸的抗精子发生药物、损伤变态过程的精子细胞和中晚期精母细胞,近期亦有人报道棉酚能进一步损伤精原细胞与间质细胞,但棉酚对人垂体性腺轴系激素的影响报道不多。本文通过测定服用棉酚1～79个月的男子血中睾丸酮,LH和FSH含量的变化,探讨棉酚对人垂体性腺轴系的影响、观察棉酚对睾丸间质细胞及生精上皮的损伤作用。     

醋酸棉酚和15甲基PGF_(2α)甲酯对大鼠子宫胞浆雌激素受体的影响

假孕大鼠口服醋酸棉酚40和80 mg/kg连续5天,平均每个子宫的胞浆蛋白和雌激素受体量明显减少。以每mg蛋白计,雌激素受体浓度同对照组差异不显著。幼大鼠口服醋酸棉酚40mg/kg连续8天,作饱和分析测得对照组和给药组K_d值分别为1.04×10~_(-10)和1.09×10_(-10)mol。最大受体结合数分别为432.0和358.8 fmol/子宫。实验发现棉酚在高浓度时对~3H-雌二醇同其受体的结合有抑制作用。15甲基PGF_(2α)甲酯对假孕大鼠子宫胞浆蛋白水平和雌激素受体均无明显影响。     

~(14)C-棉酚在四种动物体内吸收、分布和排泄的比较研究

本文比较研究了~(14)C-棉酚在小鼠、大鼠、犬和猴体内的吸收、分布和排泄过程。小鼠和大鼠于单次口服~(14)C-棉酚后6～9小时,血内放射性达高峰,生物半衰期分别为31和16.5小时。口服~(14)C-棉酚48小时后,以胃肠道内容物及肝、肾内放射性最高。睾丸内放射性大鼠比小鼠要高。进入体内~(14)C-棉酚,放射性排出主要通过粪便,少部分从尿排出。以犬和猴(各1只)进行比较研究,也获得类似结果。它们睾丸内放射性均比大鼠低。与其它三种动物比较,犬心脏内放射性最高,猴体内放射性从粪便中排出最快。本文结果提示棉酚对不同动物的抗生育作用与毒性作用之间的差异,可能与它在相应脏器内的分布、蓄积及排泄速度的不同有关。     

醋酸棉酚对雄性木鼠睾酮、黄体生成素(LH)和卵泡刺激素(FSH)的影响

给大鼠口服醋酸棉酚30mg/kg/d每周6次,给药2,4或8周,用放射免疫法测血清睾酮、LH和FSH水平。结果表明,给药2周(生精上皮破坏不明显)和6,8周(曲精细管严重破坏)血清睾酮水平显著下降,而血清LH无变化。给药8周时血清FSH显著升高,为对照组的4倍。实验结果提示棉酚可能影响间质细胞的功能。     

睾丸酮、雌二醇和棉酚合并用药的雄性抗生育作用及其安全性的研究

睾丸酮、雌二醇和棉酚合并用药的雄性抗生育作用及其安全性的研究叶惟三，但凌，郭燕，钱晓菁，应骏，薛社普（中国医学科学院，中国协和医科大学基础医学研究所，北京１００００５）减轻有抗男性生育活性棉酚的副作用是发展棉酚成为男性避孕药急待解决的问题［１，２］。...     

雷公藤多甙与棉酚合用对雄大鼠生育力的影响

本研究探讨雷公藤多甙(GTW)与棉酚合用对雄大鼠生育力的影响。SD雄大鼠用棉酚及GTW各6 mg/kg/d,灌胃给药,每周6日,共11周。10只用药动物全部不育,附睾精子密度和活率也明显下降,而体重增长如常,性行为存在。睾丸光镜下结构绝大多数无明显异常,血清睾酮水平正常,副性腺重量无明显变化。停药6周后生育力恢复。在相同剂量下,单用GTW或棉酚均无抗生育效果。表明两药合用有相加作用,为减少棉酚和GTW副作用提供一条可能途径。     

醋酸棉酚对大鼠睾网液中K~+、Na~+及睾酮水平的影响

成年雄鼠给予15mg/kg/d醋酸棉酚,连续50d灌服,导致不育,精子生成与附睾精子活力都受到明显影响。但血清与睾网液中K~+、Na~+、睾酮水平与对照组相比无明显变化。因此认为给予较低剂量的醋酸棉酚灌服大鼠,可以阻断生精作用而达到抗生育效果,但并不影响K~+、Na~+与睾酮在睾丸中分泌与转运。     

棉籽粉及棉酚的抗生育作用研究

棉籽粉对雄性大鼠有抗生育作用,其有效成份为棉酚。棉酚对雄性大鼠的抗生育作用最低有效剂量为10～12mg/kg,连续给药4～5周。停药后4～5周生育力能可逆恢复。棉酚对大鼠的交配行为及副性腺的功能均无明显的影响;亦不改变大鼠及猴血浆中睾丸酮的含量。棉酚对子代生长及生育力均无不良影响。大鼠长期服用棉酚后,心电图未见有异常变化。部分大鼠的血清谷丙转氨酶及γ球蛋白值稍有升高,停药后恢复正常。个别大鼠肝组织切片显于肝细胞有病理性改变。右旋棉酚既无明显的抗生育作用,亦无显著的毒性反应,提示棉酚的抗生育作用及毒性反应与左旋体有关。棉酚结构上的CHO基与OH基,一旦用其它基团取代,即失去抗生育作用。     

The effects of testosterone or insulin treatment on contractile responses of the rat vas deferens following castration or streptozotocin-induced diabetes mellitus

1. Castration and streptozotocin-induced diabetes produce significant decreases in serum testosterone levels accompanied by decreased vas deferens weights, a decreased responsiveness to nerve stimulation, and altered contractile responses to carbachol and phenylephrine. 2. Treatment of castrated rats with testosterone for 8 weeks prevented the decreased vas deferens weights and contractile changes associated with castration. 3. Treatment of diabetic rats with testosterone for 8 weeks prevented the decreased vas deferens weights and the supersensitivity to contractile agonists associated with diabetes. Testosterone treatment only partially prevented the decreased response to nerve stimulation. 4. Treatment of diabetic rats with testosterone plus insulin for 8 weeks prevented the decreased vas deferens weights and decreased the sensitivity to carbachol and phenylephrine compared to controls. Testosterone plus insulin treatment prevented the decreased response to nerve stimulation. 5. There were no differences in the IC50 values for nitrendipine among any of the groups studied, suggesting that the contractile changes observed in vasa deferentia following castration or diabetes are not the result of changes in calcium movements. 6. The results suggest that decreased testosterone levels are at least partially responsible for the changes in contractility of the vas deferens of streptozotocin-diabetic rats.     

Changes in testicular and serum hormone concentrations in the male rat following treatment with m-dinitrobenzene

m-Dinitrobenzene (m-DNB)-induced testicular atrophy has been attributed to a direct effect upon the germinal epithelium. However, such degenerative changes in the germinal epithelium should induce shifts in the testicular hormonal milieu, which would in turn alter the hypothalamic-pituitary gonadal axis in general. This study evaluated the endocrine status of male rats (killed 3 hr, 24 hr, 1 week, and 2 weeks) following a single oral dose of m-DNB (32 mg m-DNB/kg). Serum and pituitary leuteinizing hormone, follicle-stimulating hormone (FSH), and protactin and hypothalamic gonadotropin-releasing hormone (GnRH) concentrations were determined. Testosterone and androgen-binding protein concentrations in serum, interstitial fluid, seminiferous tubule fluid, and caput epididymis were also determined. In vitro basal and hCG-stimulated testosterone release was determined in the decapsulated testis. Results of the present study indicate that pituitary hormone concentrations and hypothalamic GnRH were unaffected after a single oral dose of m-DNB. Serum FSH was elevated at 2 weeks. There was a transient decrease in serum testosterone at 24 hr, which returned to control values at 1 and 2 weeks. Interstitial fluid, seminiferous tubule fluid, and caput epididymal testosterone concentrations were increased at 1 and 2 weeks. Basal testosterone release in vitro was increased at 2 weeks, while hCG-stimulated testosterone release was increased at 1 and 2 weeks. Androgen-binding protein concentrations in serum and interstitial fluid were increased at 1 and 2 weeks. Androgen-binding protein was increased at 24 hr and 1 week in seminiferous tubule fluid, but returned to control concentrations by 2 weeks. However, the total tubular content of androgen-binding protein was dramatically decreased at 2 weeks. Androgen-binding protein in the caput epididymis was unaltered following m-DNB treatment. These data demonstrate that m-DNB exerts a direct effect on the testes and not through alterations in hypothalamic and pituitary control of gonadal function.     

Quantitative aspects of spermatogenesis in rats and dogs after repeated hexachlorophene treatment

Hexachlorophene was administered orally, at subneurotoxic doses, to rats (5 mg/kg/day) and dogs (3 mg/kg/day) for 9 weeks: some of the rats and dogs were observed for a further 13 weeks. The serum concentrations of pituitary gonadotrophin and testosterone were unaffected in either species. No changes were induced in the testicular dimensions or semen characteristics of dogs and no macroscopic post mortem abnormalities, organ weight differences or lesions detectable by conventional light microscopy were found in their testes, pituitaries or secondary sex organs. A transient reduction in the number of germ cells counted in cross-sections of seminiferous tubules was seen in rats after 4 weeks treatment. After 9 weeks treatment, reduced spermatogonial counts were recorded in canine seminiferous tubules; in other respects spermatogenesis was proceeding normally. No delayed effects were apparent in either species. It is concluded that repeated administration of hexachlorophene at subneurotoxic levels did not induce significant impairment of spermatogenesis in rats or dogs.     

Reproductive toxicity of 2,4-toluenediamine in the rat. 3. Effects on androgen-binding protein levels, selected seminiferous tubule characteristics, and spermatogenesis

In previous studies we demonstrated reduced fertility, arrested spermatogenesis, and diminished circulating testosterone levels in rats fed 0.03% 2,4-toluenediamine (TDA) for 10 wk. These studies were extended in three experiments by determining TDA effects on androgen-binding protein (rABP) production and on seminiferous tubule structure, and on early changes in testes morphology and spermatogenesis. In the first experiment, rats fed 0.03% TDA for 10 wk showed a 7- to 9-fold increase in rABP content in testicular cytosol or in media of cultured seminiferous tubules, a 4-fold increase in serum rABP, but a two-thirds decrease in epididymal rABP levels. Testes examination by transmission electron microscopy revealed degenerative changes in Sertoli cells with, where present, normal spermatocytes and spermatids. In the second experiment, 0.03% TDA fed for 4, 6, or 8 wk resulted in a doubling of testes/body weight ratios and a highly correlated 2.5- to 2.9-fold increase in seminiferous tubule fluid volume. An approximately 50% decrease in epididymal sperm reserves was found after 6 or 8 wk of TDA exposure. After 10 wk of exposure to 0.03% TDA, testicular weight was the same as in control-fed rats but seminiferous tubule fluid volume was still elevated. These changes in testicular characteristics indicate TDA effects on Sertoli cell function, on RABP release from the testes (and epididymides), and possibly on tubular fluid transport. In the third experiment, rats fed 0.06% TDA for 1 wk showed a 25% decrease in epididymal sperm content, reduced epididymal weight, and minor structural changes in Sertoli cells. After 3 wk of 0.06% TDA feeding, sperm counts were further reduced, and were accompanied by a dramatic increase in testes weight, intense fluid accumulation, and ultrastructural changes in Sertoli cells. No significant changes in serum testosterone levels were noted in the TDA-treated rats. The results of this third experiment demonstrate TDA toxicity on testicular spermatogenesis within 3 wk of TDA feeding. The within 3 wk of TDA feeding. The findings in this study suggest that the early inhibition of spermatogenesis by TDA is mediated through Sertoli cell damage.     

Investigation of the effects of patulin on thyroid and testis, and hormone levels in growing male rats.

Patulin is a mycotoxin produced by several species of Penicillium, Aspergillus and Byssachlamys. Patulin can be produced on different food products including fruits, grains, cheese, cured meats, but in natural situations patulin is usually found in apple and apple products. In the present study, the time-dependent effects of patulin on the T3, T4, thyroid stimulating hormone, testosterone, luteinizing hormone and growth hormone levels of growing male rats were investigated. Patulin, at a dose of 0.1 mg/kg bw/day, was administered by gavage to growing male rats aged 5-6 weeks for a period of 60 or 90 days. The dose of patulin used in the present study was based on estimated human exposure levels. At the end of the experiment, serum T3, T4, TSH, testosterone, LH and GH levels of rats in control and treatment groups were analysed. In addition, the thyroid and testes were histopathologically examined by light microscopy. Results revealed that while patulin caused an increase (66.6%) in testosterone levels and a decrease (17.3%) in T4 levels of rats treated for 60 days, there was no change in the other hormone levels compared to those of the control group. When patulin treatment was extended to 90 days, increased serum testosterone (75%) and LH levels (146%) were observed. In histological examinations of the testes of rats treated with patulin, oedema, fibrosis and local Leydig cell hyperplasia in the interstitial tissue, and disorganization of seminiferous tubule epithelium were also observed. In addition, the thyroid of rats treated with patulin revealed lymphoid cell inflitration and enlargement of interstitial tissue between follicles, and degenerated colloid.