THE EFFECT OF INTRAVENOUSLY ADMINISTERED HUMAN CHORIONIC GONADOTROPHIN ON PLASMA LEVELS OF TESTOSTERONE AND 5α-DIHYDROTESTOSTERONE IN NORMAL MALE SUBJECTS

1973 ◽  
Vol 72 (3) ◽  
pp. 615-624 ◽  
Author(s):  
W. Maurer ◽  
U. Volkwein ◽  
J. Tamm

ABSTRACT HCG was infused intravenously into normal male subjects. The doses administered were 500, 100 and 50 IU, respectively. During the initial phase of the infusions the plasma testosterone (T) levels decreased. Thirty minutes after starting the infusion of 500 and 100 IU HCG, respectively, the plasma testosterone increased. Significantly elevated values were observed 60 to 180 minutes after the cessation of HCG administration. The dihydrotestosterone (DHT) concentrations in the plasma showed a varying pattern. On the average this steroid also exhibited an increase in plasma following the HCG administration. From the results no conclusions can be drawn as to the extent to which the plasma concentrations of DHT have been influenced by a secretion from the testes or by a peripheral conversion of T into DHT.

1995 ◽  
Vol 146 (1) ◽  
pp. 169-176 ◽  
Author(s):  
H Kishi ◽  
K Taya ◽  
G Watanabe ◽  
S Sasamoto

Abstract Plasma and ovarian levels of inhibin were determined by a radioimmunoassay (RIA) at 3-h intervals throughout the 4-day oestrous cycle of hamsters. Plasma concentrations of FSH, LH, progesterone, testosterone and oestradiol-17β were also determined by RIAs. In addition, hamsters were injected at various times with human chorionic gonadotrophin (hCG) to determine the follicular development. The changes in plasma concentrations of FSH after injection of antisera to oestradiol-17β (oestradiol-AS) and inhibin (inhibin-AS) on the morning of day 2 (day 1=day of ovulation) were also determined. Plasma concentrations of inhibin showed a marked increase on the afternoon of day 1, remained at plateau levels until the morning of day 4, then increased abruptly on the afternoon of day 4 when preovulatory LH and FSH surges were initiated. A marked decrease in plasma concentrations of inhibin occurred during the process of ovulation after the preovulatory gonadotrophin surges. An inverse relationship between plasma levels of FSH and inhibin was observed when the secondary surge of FSH was in progress during the periovulatory period. Plasma concentrations of oestradiol-17β showed three increase phases and these changes differed from those of inhibin. Changes in plasma concentrations of oestradiol-17β correlated well with the maturation and regression of large antral follicles. Follicles capable of ovulating following hCG administration were first noted at 2300 h on day 1. The number of follicles capable of ovulating reached a maximum on the morning of day 3 (24·8± 0·6), and decreased by 0500 h on day 4 (15·0 ± 1·1), corresponding to the number of normal spontaneous ovulations. Plasma concentrations of FSH were dramatically increased within 6 h after inhibin-AS, though no increase in FSH levels was observed after oestradiol-AS. These findings suggest that changes in the plasma levels of inhibin during the oestrous cycle provide a precise indicator of follicular recruitment, and that the changes in plasma concentrations of oestradiol-17β are associated with follicular maturation. These findings also suggest that inhibin may play a major role in the inhibition of FSH secretion during the oestrous cycle of the hamster. Journal of Endocrinology (1995) 146, 169–176


1980 ◽  
Vol 87 (3) ◽  
pp. 393-400 ◽  
Author(s):  
KAZUYOSHI TAYA ◽  
SHUJI SASAMOTO

In order to elucidate the mechanism of the resumption of follicular activity and ovulation in rats, levels of FSH, LH and prolactin in plasma and pituitary gland and ovarian follicular development were quantified after removal of the litter on day 3 of lactation (day of parturition = day 0 of lactation). Such removal resulted in ovulation of 13 oocytes 4 days later, a number comparable with that found in normal cyclic rats. Plasma levels of prolactin were high during lactation but markedly decreased after removal of the litter. Although plasma concentrations of FSH and LH did not change during days 3–7 of lactation, there was an FSH surge between 24 and 30 h after removal of the litter. Plasma concentrations of LH also increased slightly but significantly by 24 h after removal of the litter and this value persisted during the following 2 days. Surges of FSH, LH and prolactin occurred at 17.00 h 3 days after pups were removed. Removal of the litter did not increase pituitary contents of FSH, LH and prolactin and a marked reduction in pituitary levels of FSH and LH, but not of prolactin, occurred at 17 00 h 3 days after removal of the litter. A quantitative study of follicular development indicated that follicles larger than 401 μm in diameter were absent during days 3–7 of lactation. However, the number and size of antral follicles increased by 30 h after removal of the litter, probably due to the increases in plasma levels of FSH and LH, and follicles larger than 601 μm in diameter appeared 3 days after the young were removed. Although ovulation could not be induced by human chorionic gonadotrophin from days 3 to 5 of lactation, its administration 30 h after removal of the litter produced ovulation in all rats by the following morning. These results indicated that a moderate increase in FSH, although below the amounts released at the preovulatory surge, together with basal levels of LH which were within the range observed on the day of dioestrus during the normal cycle were responsible for the initiation of follicular maturation after removal of the litter.


PEDIATRICS ◽  
1976 ◽  
Vol 57 (4) ◽  
pp. 568-569
Author(s):  
Martin W. Stallings ◽  
A. Hewitt Rose ◽  
George L. Auman ◽  
Russell D. Cunningham

A 2-week-old male infant was diagnosed as having persistent Mullerian structures. Microscopically normal testes were found, as well as a uterus, cervix, and fallopian tubes. Plasma testosterone values responded normally to human chorionic gonadotrophin stimulation. This condition at times is familial, and genetic counseling is indicated. CASE REPORT A 2-week-old white boy presented with a history of a mass in the left groin. This mass was not present at birth. There is no family history of inguinal mass and the patient has no siblings. Physical examination revealed a normal male infant with a 2-cm to 3-cm hard mass in the left inguinal area.


1984 ◽  
Vol 103 (2) ◽  
pp. 227-231 ◽  
Author(s):  
A. Bartke ◽  
H. G. Klemcke ◽  
A. G. Amador ◽  
F. Talamantes

ABSTRACT Gonadal atrophy induced by short photoperiods in male golden hamsters is accompanied by a decrease in the total content of testicular prolactin and LH/human chorionic gonadotrophin (LH/hCG) receptors and a concomitant rise in the concentration of LH receptors. Atrophic testes are typically abdominal. In this study, we have compared the effects of experimentally induced cryptorchidism and the effects of a short photoperiod on testicular prolactin and LH/hCG receptors. Cryptorchidism produced the expected decrease in testicular weight and an increase in plasma FSH concentrations, without altering plasma concentrations of LH or prolactin and with a relatively small decrease in plasma testosterone. It also produced an increase in the concentration of prolactin and LH/hCG receptors without significant changes in their total content. Exposure to a short photoperiod decreased weights of testes and seminal vesicles and plasma levels of prolactin and testosterone, with no significant effects on plasma gonadotrophin levels. Short photoperiod also increased the concentration of LH/hCG receptors but, in contrast to the effects of cryptorchidism, it produced a precipitous decline in the total content of testicular receptors for both prolactin and LH/hCG. We conclude that changes in prolactin and hCG binding measured in membrane preparations from decapsulated testes of hamsters exposed to a short photoperiod cannot be explained by the abdominal position of the gonads, abnormalities of Sertoli cell function or changes in the relative proportion of Leydig cells in the atrophic testes. J. Endocr. (1984) 103, 227–231


1997 ◽  
Vol 152 (1) ◽  
pp. 147-154 ◽  
Author(s):  
A Tohei ◽  
M Akai ◽  
T Tomabechi ◽  
M Mamada ◽  
K Taya

Abstract The functional relationship between thyroid, adrenal and gonadal hormones was investigated using adult male rats. Hypothyroidism was produced by the administration of 4-methyl-2-thiouracil (thiouracil) in the drinking water for 2 weeks. Plasma concentrations of TSH dramatically increased, whereas plasma concentrations of tri-iodothyronine and thyroxine decreased in thiouracil-treated rats as compared with euthyroid rats. Hypothyroidism increased basal levels of plasma ACTH and pituitary content of ACTH. The pituitary responsiveness to CRH for ACTH release markedly increased, whereas the adrenal responsiveness to ACTH for corticosterone release decreased. These results indicated that hypothyroidism causes adrenal dysfunction in adult male rats. Pituitary contents of LH and prolactin decreased in hypothyroid rats as compared with euthyroid rats. In addition, hypothyroidism lowered pituitary LH responsiveness to LHRH. Testicular responsiveness to human chorionic gonadotrophin for testosterone release, however, was not different between euthyroid and hypothyroid animals. These results indicated that hypothyroidism causes adrenal dysfunction and results in hypersecretion of ACTH from the pituitary gland. Adrenal dysfunction may contribute to the inhibition of LHRH secretion from the hypothalamus, possibly mediated by excess CRH. Journal of Endocrinology (1997) 152, 147–154


1974 ◽  
Vol 60 (3) ◽  
pp. 429-439 ◽  
Author(s):  
K. PURVIS ◽  
N. B. HAYNES

SUMMARY Peripheral plasma testosterone levels in the male rat were increased above control levels 5 min after the first intromission with an oestrous female, or 8–10 min after first contact with the female. The levels remained raised for at least 30 min if copulation was allowed to continue. Intravenous injection of human chorionic gonadotrophin resulted in an increased peripheral concentration of plasma testosterone after 10–15 min and an increase of testosterone content of the testis 5–10 min after injection, indicating that the rat testis has a potential to respond rapidly to gonadotrophin. The results suggested that if the testosterone surge during copulation was gonadotrophin-dependent, it was initiated before the first intromission. Indeed, plasma testosterone levels were raised in male rats 5 min after being placed in the proximity of oestrous females but not allowed physical contact.


1973 ◽  
Vol 72 (3) ◽  
pp. 573-581 ◽  
Author(s):  
Gwyneth E. Jones ◽  
A. R. Boyns ◽  
E. T. Bell ◽  
D. W. Christie ◽  
M. F. Parkes

ABSTRACT Immunoreactive canine luteinizing hormone (IRCLH) and progesterone were measured in the plasma of Beagle bitches. Changes in plasma hormone concentrations during pregnancy were similar to those seen in the non-pregnant animal during metoestrus. Administration of pregnant mares' serum gonadotrophin (PMSG) and human chorionic gonadotrophin (HCG) to anoestrous bitches induced oestrus. However, the duration of progesterone secretion was shorter than that seen in pregnant bitches. Treatment appeared to stimulate the secretion of IRCLH and in some animals plasma levels reached a maximum some weeks after the end of oestrus.


Author(s):  
Atsushi Imai ◽  
Tsukasa Ohno ◽  
Miki Nakagawa ◽  
Miho Sawairi ◽  
Teruhiko Tamaya

Dihydrotestosterone (DHT) and 17β-oestradiol binding, and aromatase activity were measured in cultured genital skin fibroblasts from two siblings with the incomplete testicular feminization syndrome. Whole-cell and nuclear DHT binding in the cells from both patients were reduced to 80% and 60%, respectively of those in a normal male subject. The nuclear oestradiol binding was not impaired in the fibroblasts from the patients whose plasma oestradiol was normal or a little elevated. Although gonadectomy led to a decrease in plasma testosterone concentration, the concentration of testosterone-binding globulin showed no change suggesting no apparent effect on testosterone-binding globulin synthesis by testicular steroids. There was no significant difference in aromatase activity of the fibroblasts between the patients and the normal male subjects. The relatively increased oestrogen concentration in the syndrome might result from oestrogen production in testes, but is unlikely to be from peripheral tissues such as fibroblasts. This is the first report to examine oestradiol binding and aromatase activity in the cells from the incomplete testicular feminization associated with impaired DHT binding. These findings may give new insight into the pathogenesis of abnormal male sexual differentiation in the patients with testicular feminization syndrome.


1975 ◽  
Vol 48 (3) ◽  
pp. 219-226
Author(s):  
A. D. Efstratopoulos ◽  
W. S. Peart

1. The effect of single and combined infusions of angiotensin and aldosterone on colonic potential difference, blood pressure and renal function was studied in two normal male subjects and four female patients with adrenal deficiency maintained only on cortisone. 2. Aldosterone had its usual effect on colonic potential difference and it was possible to show that angiotensin had a small but definite effect of its own in the absence of aldosterone. The two hormones produced a summation response when given together. 3. The effects on renal function in two normal young male subjects were similar to those known previously. The response of the patients was different and probably reflected a number of factors, such as age, sex and long-standing adrenal deficiency. 4. Although the numbers were small, both normal subjects and patients showed a significantly greater rise of blood pressure with combined infusions of angiotensin and aldosterone than with angiotensin alone. The plasma concentrations of angiotensin were similar with both types of infusion, and so increased sensitivity to angiotensin in the presence of aldosterone is postulated.


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