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1.
Summary Interstitial cells from the testes of the Mongolian gerbil have been used to investigate the effects of serum proteins on testosterone production stimulated by hCG and steroidal precursors. Short-term incubation of interstitial cells with progesterone or DHEA resulted in a rapid increase of testosterone secretion; this effect was even more pronounced in the presence of calf serum. On the other hand, addition of hCG (10 mIU) had no significant effect on testosterone release during the 30-min incubation. These results demonstrate that the magnitude of the steroidogenic response of short-term incubated interstitial cells is a complex function, mainly of precursor concentrations and binding capacities of serum proteins but not of gonadotrophins.8 October 1986  相似文献   

2.
A single injection of hCG (500 IU) to intact and hypophysectomized prepubertal rat increases plasma testosterone levels and decreases hCG receptors in the testicular Leydig cells for 4 to 5 days. In intact animals testosterone exhibit a rapid increase within hours and a delayed paradoxical increase between 60 and 96 hours. In hypophysectomized animals the first peak is not present. In both intact and hypophysectomized rats hCG receptors are almost undetectable between 10 and 96 hours following hCG injection. Since receptor occupancy cannot account for this phenomenon it is concluded that hCG is exerting a negative control on its own receptors.  相似文献   

3.
After organ culture without hormone, the epithelial gland cells of Rat veantral prostate undergo atrophic changes, whereas the interstitial stroma components tend to increase. Estradiol (1-1,000 nM),added to the culture medium, is ineffective. On the contrary, testosterone (1-100 nM) maintains epithelial cells and prevents the increase of interstitial stroma. When estradiol (1-1,000 nM) is combined with a physiological concentration of testosterone (1-4 nM), the epithelial cells are well maintained, but the inhibitory action of testosterone on the stroma is counteracted so that the glandular epithelium and the interstitial stroma are both stimulated. However, when testosterone is used at supraphysiological (10-100 nM) concentrations, estradiol is completely ineffective and the structure of the prostate is identical to the one given by the androgen alone.  相似文献   

4.
The responsiveness of fetal mouse Leydig cells to catecholamines (epinephrine, norepinephrine), a beta-agonist agent (L-isoproterenol) and hCG was investigated in vitro. Fetal Leydig cells when freshly isolated were unable to respond to L-isoproterenol (10(-5) M). However, L-isoproterenol, epinephrine and norepinephrine significantly stimulated androgen production by fetal Leydig cells after 24 h of primary culture. Androgen production was increased in both conditions and to a greater extent by hCG. Propranolol blocked the stimulatory effect of L-isoproterenol and epinephrine. It is concluded that catecholamines can regulate fetal testosterone biosynthesis.  相似文献   

5.
Summary The responsiveness of fetal mouse Leydig cells to catecholamines (epinephrine, norepinephrine), a-agonist agent (L-isoproterenol) and hCG was investigated in vitro. Fetal Leydig cells when freshly isolated were unable to respond to L-isoproterenol (10–5M). However, L-isoproterenol, epinephrine and norepinephrine significantly stimulated androgen production by fetal Leydig cells after 24 h of primary culture. Androgen production was increased in both conditions and to a greater extent by hCG. Propranolol blocked the stimulatory effect of L-isoproterenol and epinephrine. It is concluded that catecholamines can regulate fetal testosterone biosynthesis.  相似文献   

6.
Various sex hormones (testosterone, oestradiol, dehydroepiandrosterone), in the form of suspensions in oil, are injected into the allantois of normal and chondrodystrophic (Creeper) chick embryos of 6 days 1/2 incubation. Observations made on each of the phenotypes on the 12th day of incubation show that oil injected alone causes a significant decrease in the dry weight of the tibiae. This inhibitory effect is partially abolished when the oil is injected together with the sex hormones, testosterone being the most effective.  相似文献   

7.
M Tsukano  M Kotani  K Matsuno  K Miyakawa  Y Nawa 《Experientia》1985,41(10):1337-1338
The induction of unresponsiveness to mycobacterial adjuvant took a longer time in male DA rats than in female rats. A shift in the induction time of unresponsiveness in males toward the female type was brought about by castration, but could be reverted to the male type by the application of testosterone. The transfer study revealed that cells capable of preventing arthritis required a longer incubation time for their development in males than in females. This suggests that testosterone inhibits the development of suppressor cells in adjuvant arthritis.  相似文献   

8.
Summary The induction of unresponsiveness to mycobacterial adjuvant took a longer time in male DA rats than in female rats. A shift in the induction time of unresponsiveness in males toward the female type was brought about by castration, but could be reverted to the male type by the application of testosterone. The transfer study revealed that cells capable of preventing arthritis required a longer incubation time for their development in males than in females. This suggests that testosterone inhibits the development of suppressor cells in adjuvant arthritis.Acknowledgments. We are grateful to The Naito Foundation Research Grant for 1983.  相似文献   

9.
目的研究D-半乳糖所致亚急性衰老小鼠学习记忆能力和睾丸的变化,并观察延衰合剂对其的治疗作用。方法选昆明系雄性小鼠,用D-半乳糖建立亚急性衰老模型。应用Morris水迷宫实验测试衰老小鼠学习记忆能力的变化;电镜技术观察延衰合剂治疗后衰老小鼠睾丸的形态学改变;酶联免疫分析法检测血清睾酮的变化。结果衰老小鼠学习记忆能力下降,睾丸重量减少,生精细胞减少,结构紊乱,功能障碍,血清睾酮含量明显降低。在改变学习记忆能力上延衰合剂高剂量组作用明显优于延衰合剂低剂量纽(P〈0.05),但与补肾益寿胶囊纽及延衰舍剂中荆量组差畀无显著性(P〉0.05)。结论延衰舍剂可以提高衰老小鼠学习记忆能力,改善睾丸生精小管的超微结构,抑制衰老小鼠血清睾酮含量的下降,具有一定的延缓衰老作用。  相似文献   

10.
Summary The effect of different densities of animals per cage on basal testosterone secretion and its response to some stimuli was studied in prepuberal male mice. Mice housed with 110 or 55 cm2 of floor space per animal showed the same basal serum testosterone and hCG-induced testosterone release. Likewise, in a second experiment, the same basal serum testosterone and a similar response to acute noise stress were found in mice housed at 132, 66 or 22 cm2 of floor space per animal. These results suggest that post-weaning crowding did not affect Leydig cell function in male mice.  相似文献   

11.
Boar Leydig cells undergo a strong atrophy from 1 to 3 months after hypophysectomy but can be reactivated by the gonadotropin HCG in organ culture conditions. This reactivation which appeared at histological and ultrastructural level was evidenced by the capacity of testicular tissue to synthesize testosterone as judged by radioimmunoassay. Both synthesis in the tissue and release into the medium increased according the incubation time with HCG; the adjonction of 17 alpha-OH-pregneolone to culture medium led to increase the intra and extra-tissular concentration of testosterone.  相似文献   

12.
Summary The treatment of 62 patients with chlorpromazine was followed by a rise of SGO-T in the serum in 20% of them. Six other patients were treated with a daily dose of 200 to 400 mg Methylthiouracil for 14 days. No elevation of serum transaminases was observed. The application of a daily dose of 30 mg methyl testosterone to 40 other patients was followed by a rise of SGO-T and SGP-T in 77% of them. The maximal elevation of SGO-T was 275 U. and of SGP-T 260 U., and this was reached during 10 days of therapy on an average. This effect is bound to the methyl group of methyl testosterone, since in 10 patients, treated with the same dose of testosterone propionate, the serum transaminases activity were not influenced.  相似文献   

13.
Summary In incubations of decapsulated mouse testes with a maximally stimulating dose of hCG, the accumulation of testosterone was not affected by the addition of PRL at concentrations from 0.1 to 50 μg/ml or GH at concentrations from 0.5 to 25 μg/ml. This work was supported by NIH through grants HD 12642 and HD 12671. We thank NIAMDD for the supply of pituitary hormones and Dr B.V. Caldwell for antiserum to testosterone.  相似文献   

14.
A Castro  P Buschbaum  M Nadji  W Voigt  S Tabei  A Morales 《Experientia》1979,35(10):1392-1393
Immunoreactive human chorionic gonadotropin (hCG) was found in 9 of 65 surgically removed malignant breast tumors. Concentrations ranged from 5 to greater than 500 mIU hCG/g tumor. hCG was measured by a beta-chain specific readiommunoassay. In further study of these specimens, an immunoperoxidase staining technique was used to stain for hCG in formalin-fixed sections. The hCG was shown to be localized within the cytoplasm and on the surface of the malignant cells.  相似文献   

15.
Summary Chronic administration of potassium canrenoate (SC-14266), a water-soluble anti-aldosterone agent, increased serum LH levels in male rats without altering serum levels of FSH, prolactin, testosterone and progesterone. The increase in serum LH may be due to the anti-androgenic effect of potassium canrenoate.Acknowledgments. The authors thank the Rat Pituitary Hormone Distribution Program, NIAMDD, NIH and Dr A.F. Parlow for radioimmunoassay materials.  相似文献   

16.
After the interstitial tissue was cultivated, the radio-immunoassay revealed in the media very small quantities of free testosterone but much larger quantities of testosterone conjugates as glucuronids and sulfates. Association of pituitaries increases greatly the secretion. 12-13 days precultivated pituitaires retain close to 70% of their stimulating potency.  相似文献   

17.
Summary Studies were carried out on the influence of testosterone on the growth of seminal vesicles in relation to age. Moreover, the postnatal development of the secretory cells in seminal vesicles was investigated by electron microscopy, and the functional morphology of the epithelial cells at the moment of first effect of testosterone was discussed.  相似文献   

18.
Summary Immunoreactive human chorionic gonadotropin (hCG) was found in 9 of 65 surgically removed malignant breast tumors. Concentrations ranged from 5 to greater than 500 mIU hCG/g tumor. hCG was measured by a -chain specific radioimmunoassay. In further study of these specimens, an immunoperoxidase staining technique was used to stain for hCG in formalin-fixed sections. The hCG was shown to be localized within the cytoplasm and on the surface of the malignant cells.  相似文献   

19.
20.
J M Gasc  M Thibier 《Experientia》1979,35(10):1411-1412
After testosterone propionate treatment (1 or 2 mg per embryo), plasma testosterone in chick embryos rises to 500 times higher than in control animals, and then progressively diminishes during the following days of incubation. These drastic changes in hormonal status after the TP treatment entails consequences that may be considered pharmacological rather than physiological.  相似文献   

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