Inhibition and Stimulation of Testes in Rats Treated With Testosterone Propionate

Shay, Harry; Cohen, Jarrod; Paschkis, K. E.; Fels, Samuel S.

doi:10.1210/endo-28-3-485

Cited by 14 publications

(2 citation statements)

References 9 publications

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“…If it is accepted that the effects of HCG are mediated by testosterone, the combination of FSH and testosterone would command the hormonal control of spermatogenesis at those steps. The late meiotic actions of testo¬ sterone observed by us coincide with data reported by Steinberger (1971), and, as proposed by Shay et al (1941), spermatogenic stimulation by testosterone is characterized by a quantitative cellular increase of elements already present and not by the appearance of more mature steps. Furthermore, it confirms the opinion of Woods & Simpson (1961) that it is impossible to induce precocious spermatogenic maturation in immature rats.…”

Section: Discussionsupporting

confidence: 89%

Effect of gonadotrophins and testosterone on the seminiferous tubules of the immature rat

Chemes¹,

Rivarola²,

Bergadá³

1976

Reproduction

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The actions of HCG and PMSG for different periods and of testosterone of the immature rat testis were studied. Short-term administration of HCG (1-3 days) induced an early meiotic and postmeiotic stimulatory effect but a decrease in spermatogonial numbers. Administration of HCG for longer periods (10 days) caused a reduction in numbers of all cell types. Treatment with HCG + PMSG reduced the amount of inhibition, while PMSG alone resulted in histological and humoral signs of stimulation of the interstitial tissue and the meiotic and postmeiotic stages; the numbers of spermatogonia were not affected. Testosterone caused stimulation of the meiotic and postmeiotic stages and a reduced number of spermatogonia. It is concluded that while PMSG directly stimulates spermatogonia, HCG acts through testosterone secretion at the meiotic and postmeiotic stages. The early inhibitory effects of HCG and testosterone on spermatogonial numbers could be ascribed to the inhibition of endogenous FSH by androgens.

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Section: Discussionsupporting

confidence: 89%

Effect of gonadotrophins and testosterone on the seminiferous tubules of the immature rat

Chemes¹,

Rivarola²,

Bergadá³

1976

Reproduction

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“…This they consider due to the fact that, while in both cases there is an inhibition of pituitary function and so of natural androgen secretion, only with heavy dosage is sufficient androgen introduced to maintain spermatogenesis. Further, Shay, Gershon-Cohen, Paschkis & Fels (1941) report that large doses of androgens stimulate spermato genesis in immature rats, while Cutuly & Cutuly (1940), using testosterone propionate, have induced and maintained spermatogenesis in hypophysectomized rats. The experi ments with mice and rats have usually been complicated by the existence in a functioning state of the natural mechanism for testis stimulation, but in annually breeding mammals experiment is easier.…”

Section: Discussion (1) Mitotic Activity In the Mouse Ovarymentioning

confidence: 99%

Mitotic activity in the adult female mouse,Mus musculusL. A study of its relation to the oestrous cycle in normal and abnormal conditions

1946

Phil. Trans. R. Soc. Lond. B

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A survey has been made of the mitotic activity of the reproductive system, the urinary system, the alimentary canal, various exocrine and endocrine glands, and other miscellaneous organs of the adult female mouse, both in relation to the normal oestrous cycle and to injections of oestrone. A similar survey has also been made of the mitotic activity associated with wound healing and with cancerous growth. Evidence is recorded which indicates that, in all these cases, mitosis is stimulated by oestrogenic hormones. In the ovary, the cells are highly resistant to the mitosis-stimulating effect of the oestrogen. Mitotic activity in this organ is induced mainly by the pools of follicular fluid which are particularly rich in oestrogenic hormone, and which stimulate the highest rate of division in any cells in direct contact with them. Thus, the follicular fluid causes the great mitotic activity associated with follicle growth, and after the follicle bursts, also induces the mitotic activity of the neighbouring germinal epithelium which it bathes. In the same way, some mitotic activity is stimulated in the developing corpus luteum before luteinization occurs. In the other body organs there exists the widest range of sensitivity to oestrogenic hormones. In the brain no mitotic activity was seen; in the kidney there was some activity at full oestrus or after many injections of oestrone; in the epidermis there was a considerable reaction; and some of the most sensitive tissues of the body proved to be the lining epithelia of the Müllerian duct system and the intestinal mucosa. The less active tissues responded slowly to oestrogen stimulation, while the more active tissues responded promptly and fully. The most active tissues examined proved to be the proliferating centres of the intestinal lymph nodules, which maintained a maximum rate of cell division even when, as on the first day of dioestrus, the oestrogen blood content was at a minimum. The results obtained indicate the existence of mitosis inhibitors. First, there is the force, termed the cell inertia, which must be overcome before any tissue can react by cell division to the presence of an oestrogen. In the case of less active tissues the cell inertia is great, and is overcome only after the oestrogen has exerted its influence for several days, but in the more active tissues the cell inertia, is slight, and is rapidly overcome by relatively small increases in the oestrogen blood content. The existence of a second mitosis inhibitor, termed the mitosis depressor, is shown by the fact that any sharp rise in mitotic activity is quickly brought under control, so that mitosis is again reduced to a minimum. With the continued presence of the stimulating oestrogen, there is, after a short interval, a second rise in mitotic activity which, like the first, is rapidly brought under control and in turn eliminated. Thus, even in the continued presence of oestrogen stimulation, mitotic activity proceeds in waves. However, an exception to the rule is furnished by the proliferating centres of the intestinal lymph nodules where it appears that both the mitosis-controlling forces are lacking, so that a maximum rate of cell division is always maintained. It was discovered that, during wound healing, the mitosis rate rises sharply to an abnormally high maximum, and that it does this quite irrespective of the oestrous cycle and of injections of oestrone. It is evident, therefore, that the mitotic activity associated with wound healing is under the control of some special mechanism, and evidence is summarized which indicates that one of the functions of wound hormones is the elimination of the two mitosis-regulating forces in tissues closely adjacent to the wound. Because of this, the local cells react immediately and in an abnormal degree to the stimulation of the oestrogenic hormones, even if these are present only in small concentrations. In cancerous growth it was found that great mitotic activity also proceeds without influence from the oestrous cycle or from injections of oestrone, and it is evident that in this case the two mitosis-regulating forces are permanently in abeyance, so that the maximum response to oestrogen stimulation is always possible. It is concluded that in the adult female mouse, and probably in other animals, there exist three types of substances influencing mitotic activity. First, there are the oestrogenic hormones which act as general mitosis stimulators; second, there are the mitosis-inhibiting forces of cell inertia and mitosis depression, which prevent the rate of cell division from becoming excessive and unregulated; and third, there are the wound hormones which, by weakening the mitosis-inhibiting forces, allow an abnormally high reaction to oestrogen stimulation and a consequent rapid production of new tissue to meet the emergency. This conclusion is discussed in relation to several biological problems, including ovarian function, pregnancy, embryonic growth, and cancer.

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Local maintenance of spermatogenesis by intratesticularly implanted pellets of testosterone in hypophysectomized rats

Dvoskin

1944

Am. J. Anat.

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The maintenance of spermatogenesis in hypophysectomized rats by means of the injection of androgen in oil was first reported by Wdsh, Cuyler and McCullagh in 1934. I n these experiments, spermatogenesis was maintained for 20 days by the daily injection of an extract of male urine. This finding was confirmed by Nelson and Gallagher ('36) who extended the period of maintenance to 39 days. Nelson ('3'7) obtained maintenance for 60 days, and later ('40) for 178 days. The animals sired litters during the latter part of the period of treatment. From control experiments in which it was found that fertility persisted in androgen-treated hypophysectoinized animals longer than did motility of sperm in androgen-treated castrates, Nelson ( '37) demonstrated that the androgen injections caused a true maintenance of spermatogenesis, not merely the prolongation of the life of the sperm which were present at the time of hypophysectomy.The injection of a large number of synthetic androgens which have not been found to occur in nature, as well as crystal-Foundation. of Philosophy, in the Faculty of Pure Science, Columbia University. 'Aided by a grant, administered by Dr. P. E. Smith, from the Rockefeller * Submitted in partial fulfillment of the requirements for the degree of Doctor TABLr; 1-Absolute and relative weights of ventral prostates and seminal vesicles of hypophysectomiaed (Hypx.), crnoperated normal and castrute rats. One group of hypophysoctomi2ed rats was untreated; the others, at the t h e the hypophysis was ablated, received implants of pellets which contained various percentages of testosterone. Autopsie8 were performed 20 days later except for the last two groups which were autopsied after 40 days. Relative Hypx.contr. = 11.00

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Inhibition and Stimulation of Testes in Rats Treated With Testosterone Propionate

Cited by 14 publications

References 9 publications

Effect of gonadotrophins and testosterone on the seminiferous tubules of the immature rat

Effect of gonadotrophins and testosterone on the seminiferous tubules of the immature rat

Mitotic activity in the adult female mouse,Mus musculusL. A study of its relation to the oestrous cycle in normal and abnormal conditions

Local maintenance of spermatogenesis by intratesticularly implanted pellets of testosterone in hypophysectomized rats

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