Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have measured, by radioimmunoassay, FSH and LH in the blood plasma and in the hypophysis of castrated male rats, injected with epididymal inhibin; we have also evaluated the FSH and LH releasing activities of their hypothalamus by measuring plasma FSH and LH levels of spayed female rats, treated by hypothalamic extracts of the previous rats. The FSH and LH pituitary levels do not change compared with controls, and it is impossible to know if inhibin acts directly on hypophysis; it is likely that, directly or indirectly, inhibin restrains at the same time the synthesis and the release of FSH. On the contrary, the hypothalamic extracts lose their FSH-RH, but not their LH-RH, activities; then, inhibin operates on hypothalamus by suppressing of the synthesis of FSH-RH.
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PMID:[Evidence of an epididymis factor inhibiting the hypothalamic synthesis of FSH-RH in the rat]. 14 48

Concentrations of high affinity (Ka equals 5.5 plus or minus 0.83 times 10-8M-1) androgen binding activity in carbonextracted rat testicular supernatants have been determined by Scatchard plot analysis under a variety of hormonal situations: (a) 0-90 days following hypophysectomy; (b) 0-60 days of daily injection of NIH-FSH-P1 (150 mug) beginning 1 day after hypophysectomy; and (c) 0-60 days of daily FSH treatment beginning 30 days after hypophysectomy. The high affinity binding component declined from 0.32 pmoles/mg protein intact adults to 0.28, 0.17, and less than 0.08 (limit of detectability) pmoles/mg protein at 11, 16 and 31 days, respectively. FSH treatment beginning immediately after surgery slowed this decline, giving values of 0.30, 0.17, and 0.12 pmoles/mg protein after 11, 29, and 54 days of treatment, respectively. Expressed as pmoles per testis this represented 96, 61, and 40% of the intact control level. Similar effects on the level of androgen binding protein (Rf 0.54) were measured by steady-state polyacrylamide gel electrophoresis (PAGE). The concentration in both testis and epididymis declined gradually to nondetectable levels by 30 days after surgery. FSH treatment for 11, 29, and 54 days, respectively, resulted in 0.37, 0.38, and 0.03 pmoles of sites/mg protein in testis compared to 0.34 in intact controls and 5.7, 2.6, and 0.2 pmoles/mg protein in epididymis compared to 2.8 in intact controls. Doses of 80, 150, and 300 mug FSH/rat/day for 3 days beginning 30 days after hypophysectomy when postmeiotic elements of the germinal epithelium had degenerated caused graded increases in both testicular and epididymal levels of androgen binding protein. Prolonged FSH treatment (150 mug) under these conditions resulted in an increase in binding activity to a level of 0.12, 0.19, 0.17, and 0.20 pmoles/mg protein after 3, 11, 25, and 56 days of treatment. On a per testis basis this represented less than 20% of intact control levels. PAGE estimates were comparable except at the long treatment intervals. These results indicate that FSH treatment influences the level of androgen binding protein in adult testis and epididymis. This may reflect a direct influence on synthesis, degradation, and transport and/or indirect effects on general maintenance and responsiveness of the pertinent cell types.
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PMID:Hormonal influences on the level of testicular androgen binding activity: effect of FSH following hypophysectomy. 16 82

Male (1--60 days old) and female (1--30 days old) hamsters were decapitated and serum levels of LH, FSH, PRL, progesterone, androgens (males), and estradiol (females) were measured by RIA. Males and females had similar levels of LH until 15 days of age and of FSH until 12 days of age, at which times gonadotropin levels increased significantly in females. Peak levels for females occurred on days 19--21 for LH and on days -2--24 for FSH, later than the times reported for female rats. Adjusting female gonadotropin peaks for gestation length places these peaks for hamsters and rats at the same time in postmating age. In female hamsters, large variations occur in LH between 16--25 days of age, as reported for female rats. Males reached peak serum levels of LH and FSH on day 40, just before the first motile epididymal sperm. Serum PRL levels were identical in male and female hamsters until at least day 30. PRL levels sharply increased in both sexes after day 18 and remained elevated until at least day 30. In males, serum androgens were low until 30 days of age, in contrast to high levels reported for infantile rats. Androgens rose sharply in male hamsters after day 30 to peak levels on day 50. Progesterone in males also remained low until after day 30. Serum estradiol in females did not attain the extremely high elevations seen in rats. Some fluctuations occurred between 10--30 days of age, which presumably represent maturational changes in the ovary. Serum progesterone in females followed a pattern of development similar to estradiol.
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PMID:The development of gonadotropin and steroid hormone patterns in male and female hamsters from birth to puberty. 47 8

Thirty-one (31) subfertile men with idiopathic iligozoospermia were treated by a daily oral medication of 600 units of pancreatic kallikrein (Padutin(R) 100) over a period of 3 months. Total sperm output increased significantly with a maximum 3 months after initiation of therapy. In addition, quantitative and qualitative sperm motility improved during treatment and was still improved 2 months after withdrawal of therapy. Compared to other regimens, oral administration of 600 units kallikrein for a period of 3 months yielded better results than shorter medication periods or lower dosage. Quantitative determination of several serum proteins occurring in seminal plasma before, during and after kallikrein therapy showed a significant increase of alpha 1, x-antichymotrypsin. Thus, kallikrein treatment seems to affect, to a certain degree, the secretory activity of the accessory glands or the blood-seminal plasma barrier. Determination of serum gonadotropins and serum testosterone levels showed a significant increase of LH and testosterone during kallikrein treatment, whereas FSH was unaffected. Thus, systemic kallikrein administration induces significant changes of the pituitary-gonadal axis influencing spermatogenesis and epididymal sperm maturation. However, the local action of kinins as pharmacological active tissue hormones has to be considered too.
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PMID:Determination of various semen parameters and sex hormone levels in subfertile men during kallikrein therapy. 49 34

Aromatization was measured in testicular microsomal preparations obtained from rats treated 3--4 days with FSH, hCG, or vehicle, hCG, but not FSH, was found consistently to stimulate testicular aromatase activity at least 10-fold. As a marker for FSH action, epididymal androgen-binding protein was assayed and found to be 3 times higher in FSH-treated rats than in either hCG or control rats. hCG, but not FSH or vehicle, stimulated serum testosterone levels more than 100-fold. In all groups, aromatase activity in the microsomal fraction was at least 6 times higher than that found in the mitochondrial fraction. In experiments in which testicular compartments were separated, microsomal preparations from interstitial tissue of hCG-treated rats had 5--7 times more aromatase activity than microsomes from seminiferous tubules and 2--3 times more activity than microsomes from whole testes. It is concluded the hCG administered in vivo can stimulate testicular aromatase activity in immature rats, and the increase in activity is localized in the interstitial tissue.
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PMID:Testicular aromatization in immature rats: localization and stimulation after gonadotropin administration in vivo. 57 93

Treatment of immature, hypophysectomized male rats with 50 micrograms ovine FSH (NIH-FSH-S12) twice a day for 5 days stimulated the maximum quantity of 17 beta-hydroxyandrogen produced by isolated Leydig cells in response to hCG. Pretreatment of the FSH preparation with an LH antiserum in one study markedly reduced and in another study completely abolished this stimulatory effect of FSH, but only slightly impaired the capacity of the hormone to stimulate the Sertoli cell in vivo (epididymal androgen-binding protein). Administration of another highly potent FSH preparation (LER-1881) had no discernible effects on the dose-response characteristics of the Leydig cells but was superior to the NIH-FSH-S12 in its capacity for stimulating the Sertoli cell. When all hormone preparations were tested for their ability to stimulate steroid secretion from normal Leydig cells in vitro, a close correlation was obtained between their Leydig cell-stimulating activity (a measure of LH contamination) and their capacity to alter Leydig cell responsiveness after in-vivo treatment. FSH treatment had no effects on specific LH binding per 10(6) Leydig cells. It is concluded that the stimulatory influence of FSH on rat Leydig cells may to some extent be a result of the LH contaminating the hormone preparation.
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PMID:LH contamination may explain FSH effects on rat Leydig cells. 57 30

Seminiferous epithelium histology, Leydig cell density, and in vitro testosterone synthesis were quantitated in bilateral testicular biopsies from men with varying degrees of unilateral or bilateral varicoceles. Results were correlated with plasma levels of gonadotropins (follicle-stimulating hormone [FSH], luteinizing hormone [LH]) and testosterone (T), as well as with semen quality. In patients with bilateral varicoceles, spermatogenesis, Leydig cell density, plasma T levels, and in vitro T synthesis were significantly lower than in patients with unilateral varicoceles. Varicoceles appeared to affect maximally the latest stages of spermatogenesis. A negative correlation between FSH and LH levels and spermatogenesis was observed; however, a dissociation between the two gonadotropins occurred when spermatogenesis declined. Plasma T levels were within the normal range in all patients. The T:LH ratio was significantly correlated with spermatogenesis and sperm motility. Leydig cell density was abnormally low in oligospermic patients, and it was significantly correlated with in vitro T synthesis, spermatogenesis, sperm motility, and semen volume. Sperm count and motility were significantly correlated in this group of patients, suggesting a common pathophysiology for the effect of varicocele on spermatogenesis and sperm motility. This common pathophysiology appears to be disturbed Leydig cell function resulting in decreased testicular androgen production, in turn causing inadequate spermatogenesis and epididymal function.
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PMID:A possible mechanism for the detrimental effect of varicocele on testicular function in man. 72 Jun 47

Sixty-day-old rats were divided into four groups and treated for 30 days with either medroxyprogesterone acetate (Provera), gonadotropins (bovine LH and ovine FSH), Provera plus gonadotropins, or saline. The progestin treatment resulted in a lowering of plasma levels of testosterone, androstenedione, and LH, as well as in a reduction of epididymal sperm counts and accessory sex organ weights. The progestin-treated groups showed markedly lower levels of testicular 17 beta-hydroxysteroid dehydrogenase activity (35% of controls) and delta 5,3 beta-hydroxysteroid dehydrogenase activity (70% of controls). Rats treated with only gonadotropins exhibited reduced 17 beta-hydroxysteroid dehydrogenase but increased delta 5,3 beta-hydroxysteroid dehydrogenase activities. It was concluded from these results that progestins may affect testicular steroidogenesis and spermatogenesis not only by reducing LH secretion but also by a direct effect on the testis, as LH suppression could not account for the inhibition of 17 beta-hydroxysteroid dehydrogenase activity. Long term progestin treatment did not alter the steroidogenic response of the testis to acute administration of LH, although the testosterone to androstenedione ratio in plasma was decreased.
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PMID:A direct effect of medroxyprogesterone acetate on 17 beta-hydroxysteroid dehydrogenase in adult rat testis. 74 49

The present status and perspectives in the control of fertility in the male have been reviewed. There are two potential sites in the male reproductive processes that can be used as targets for regulation of fertility in the male: (1) inhibition of spermatogenesis, and (2) interference with sperm maturation in the epididymis. A variety of compounds tested for their antispermatogenic action in laboratory animals have no future for the control of fertility in the human male because of a number of undesirable side effects (cf. Prasad, 1973). Progestational compounds inhibit spermatogenesis by affecting the hypothalamo-hypophysial system and result in impairment of libido. The possibility of adjustment of the minimal dose of progestational compounds required to induce suppression of spermatogenesis and reduction of plasma testosterone to a level compatible with the maintenance of normalcy of libido and potency needs to be studied. A new approach to contraception in the male involves the use of a combination of progestational compounds for suppression of spermatogenesis along with testosterone (administered through silastic capsule implants or as intramuscular injections) for maintenance of libido and accessory sex gland function. A number of such combinations have been tested clinically with some success. However, the limitations of side effects, such as weight gain, gynecomastia, and psychological complications preclude their long-term use for contraception in man. Short-term use of these combination regimens by the male for 1 year followed by use of a contraceptive method by the female may be desirable to encourage partnership in family planning. Although testosterone and other androgens suppress spermatogenesis in man, the feasibility of their use for contraception depends on the establishment of a dosage and mode of adminstration that provide antispermatogenic action without causing more general metabolic alterations. Inhibition of spermatogenesis by selective interference with the action of FSH on the Sertoli cells by active or passive immunization or by selective suppression of synthesis and release of FSH by administration of "Inhibin" offers exciting possibilities in the control of fertility in the male. Studies on the physiology of the rete testis highlight its importance as a post-tubular site of action of antifertility agents in conveying (to the epididymis) compounds interfering with epididymal functions and/or viability of spermatozoa. A new approach to the induction of functional sterility in the male by selective alteration of epididymal function by a local androgen deprivation effect has been successfully tested in clinical trials. Small doses of cyproterone acetate, administered orally, result in maintenance of libido and accessory sex gland function accompanied by a decrease in the motility of ejaculated spermatozoa and incomplete inhibition of spermatogenesis...
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PMID:Target sites for suppressing fertility in the male. 79 48

The effect of age at hypophysectomy on the response of the regressed rat testis to testosterone propionate (TP) and FSH with respect to androgen-binding protein (ABP) levels was studied in individual animals. All treatments were begun 30 days after surgery. Treatment of rats 35, 45, 55 and 75 days of age at surgery with TP (1 mg/260 g for 25 days) significantly increased the level of ABP in the testes of animals in all age groups except those hypophysectomized at 35 days of age. TP treatment did not significantly elevate epididymal levels of ABP above those found in untreated rats in any age group. In animals hypophysectomized at 100 days of age, acute treatment (3 days) with FSH (150 and 300 mug/day) significantly increases the ABP levels per testis and per epididymis. Similar treatment with 750 mug TP/day did not result in a statistically significant increase in testicular ABP. No synergism between the two hormones was noted under the conditions described. Significant restoration of testicular ABP levels per mg protein was achieved with 1 mg TP/day by 5 days of treatment. Treatment of hypophysectomized adult rats with FSH raised the epididymal/testicular ratio of ABP to about 40% of that found in intact rats while comparable treatment with TP (750 mug/day for 3 days or 1 mg/day for 10 days) only slightly affected the ratio. It is postulated that FSH may facilitate ABP transport to the epididymis in addition to affecting its production by the testis.
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PMID:Effect of testosterone propionate on ABP levels in rats hypophysectomised at different ages using individual sampling. 83 63


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