2.雄性性機能と加令

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To elucidate the aging process of male reproductive function, testis and ventral prostate from rats of various ages as well as response of the latter tissue to the administered testosterone were examined biochemically.<BR>The weight of testis reached to a constant maximum level by 14th week after birth and no significant change was observed hereafter. However, accessory sex organs gained weight further and reached to a maximum level at 10 weeks later, then the tissue tended to gradural involvement with age. According to these observations, rats of more than one year-old were referred to as the "aged" in this experiment. Contents of RNA and DNA in testis showed decreasing tendency with age after maturation, while the tissue contents of protein and water did not exhibit any significant changes in rats of various ages examined. The tissue concentration of ascorbic acid also decreased slightly along the time after maturation. Among the enzymes examined, activities of LDH, MDH and ICDH in the soluble fraction and acid, alkaline phosphatases and β-glucuronidase in the homogenate in aged testes were not different significantly from those of young or adult ones. Although an impairment of sperm formation was reveald morphologically, the activity of DNA-polymerase was not impaired significantly. A most conspicuous difference between young or adult and aged testes in the biochemical parameters examined was found in the activity of testosterone formation in vitro from progesterone as the substrate. In this instance, only 1/3 of the activity was detected in testes from aged animals. An examination of the activity of protein biosynthesis in the tissue assessed by the rate of radioactive phenylalanine incorporation revealed only a slight difference between rats of various ages.<BR>In ventral prostate, the ratio of RNA to DNA contents showed progressive decrease with age. In addition, a marked decrease in tissue citrate content from aged animals was noticed. An interesting feature was observed in the activity changes of acid and alkaline phosphatase, activity of the former enzyme did not exhibit any changes throughout the experimental period, while the latter enzyme showed a tendency of abrupt increase in the animals of more than one year-old. ATPase activity was remained constant, however, RNA-polymerase in nucleus was slightly decreased irrespective of ionic strength of the incubation medium used for the activity determination in aged tissues. It was quite impressive that steroid 5α-reductase and 17β-dehydrogenase, both participate in the testosterone metabolism behaved differently with age, the former decreased to the half level in aged tissues but the latter did not differed significantly. The degree of response of castrated, aged rats to the externally administered testosterone was also determined. The weight and content of RNA in ventral prostate of animals of various ages responded in almost same pattern to the administered testosterone, however, the degree of the increase in DNA-polymerase activity and in DNA content was diminished significantly in aged tissues.<BR>In the human male, the sexual potency decrease characteristically in castrates and hypogonadotropic eunuchoidisms. Those sexual potency can be controlled with androgenic hormone successfully, in addition those masculine structure to normal condition altogether. Thus, we believe that the androgenic hormone is effective to regain the sexual potency.<BR>In aging males, many investigators suggest, that the secretion of androgenic hormone may decrease at the slow rate. In our many clinical experiences on the therapy of the psychic impotence in aging males, we get some androgenic hormones in our therapeutic programs ordinarily. Those effect is most remarkable as a "trigger", that may can improve those sexual pattern.
日本内分泌学会の論文

2.雄性性機能と加令

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