摘要:

A bioassay for inhibin, based on a dose-dependent suppression of HCG-induced ovarian weight increase in intact, immature female rats, is described. The method is specific and has acceptable sensitivity and precision such that it lends itself to statistically valid quantitative assay of inhibin activity. Being a 24-hour assay, it is conveniently and rapidly performed as well as being a multiple bioassay for estimating potencies of various preparations.

ISSN:1663-2818    

DOI:10.1159/000178720

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

The therapeutic effectiveness of intramuscularly administered testosterone esters and free testosterone in suppositories was investigated by the measurement of plasma testosterone and LH levels after administration to normal and hypogonadal men. Testosterone levels were elevated above the lower physiological limit for 1 day after 25 mg testosterone propionate, for 2 days after 50 mg testosterone propionate and for 14 days after 250 mg testosterone oenanthate. LH levels were suppressed for the corresponding periods. Elevated plasma testosterone and suppressed LH levels were maintained by testosterone suppositories (3 × 20 mg for 5 days)

ISSN:1663-2818    

DOI:10.1159/000178721

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

The effects of prolactin and prolactin plus progesterone (P-P) on the testes of adult rats were investigated. The weight of testes, seminal vesicle and the lipid composition of testes were studied 24 h after the administration of hormones. Prolactin treatment increased the weight of seminal vesicles but did not affect testicular weight, whereas P-P treatment had markedly reduced the weights of testes and seminal vesicles. Progesterone did not have any effect on the weight of testes and seminal vesicles. Both treatments had significantly reduced the total testicular lipids, which was more pronounced in the P-P treated group (28, 50 %, respectively). The esterified cholesterol was increased by the administration of prolactin and P-P with a concurrent fall in the free cholesterol. The total cholesterol was depleted only by prolactin treatment. Testicular phospholipids, particularly the phosphatidylcholine and phosphatidylethanolamine were markedly depleted by these hormones. This action of prolactin is more significant in the presence of progesterone. The depletion of phospholipids appears to be mainly due to enhanced flow of testicular tubular fluid carrying away phospholipids from testis rather than a shift in the biosynthetic pathway favouring glyceride formation. In our previous study, it has been shown that progesterone favours accumulation of esterified cholesterol by depleting the available free cholesterol. Prolactin on the other hand depletes phospholipids and total cholesterol, increases esterified cholesterol. Thus, prolactin appears to have a role in steroidogenesis as well as in the secretory processes of the testis.

ISSN:1663-2818    

DOI:10.1159/000178722

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

The rat ovary during the 1st postnatal week is unresponsive to luteinizing hormone (LH), but responds to prostaglandin E1 with increase of cyclic adenosine 3´, 5´-monophosphate synthesis. In the present experiments unresponsiveness of ovaries of 6-day-old rats to LH in synthesis of cAMP was effectively reversed by injection of depot estradiol and diethylstilbestrol on the 2nd and 4th postnatal day. Administration of testosterone, progesterone, deoxycorticosterone, pregnant mare’s serum gonadotropin and human chorionic gonadotropin had no stimulatory effect. The lack of response to LH also failed to be reversed when estradiol was injected 21 h before killing of the animals or the ovaries were preincubated with estradiol. These results suggest that the development of an ovarian cell system responsive to LH in newborn rat may be accelerated by long-term action of estrad

ISSN:1663-2818    

DOI:10.1159/000178723

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

The influence of two different grades of exogenous hypercortisolism on body weight, epididymal fat pad weight and the total number of fat cells in epididymal fat pads was investigated in young, growing rats. Cortisol, 4–5 mg/kg/day orally from the 7th to the 9th week, reduced body weight gain, whereas epididymal fat pad weight and fat cell content did not differ from those of the control rats. Cortisone acetate, 2.5 mg per 100 g, given subcutaneously for 2 weeks to rats 4–11 weeks of age caused in the young rat (4–6 weeks) a partial inhibition of the normal increase in body weight, whereas in the young-adult rat (6 weeks and older) an actual decrease of body weight was seen. At both dose levels and -with respect to the higher dose level – in all age groups studied, the weight and fat cell content of the epididymal fat pad were not changed by the cortisone (cortisol) tr

ISSN:1663-2818    

DOI:10.1159/000178724

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

In perifused pancreatic islets, the fluorescence of reduced pyridine nucleotides was recorded continuously. D-Glyceraldehyde (5 mM) or 3-o-methylglucose (27.5 mM) never caused a net fluorescence increase. Since stepwise changes of the D-glucose concentration between 0 and 20 mM always induced a fluorescence increase, it is concluded that glucose on the one hand and glyceraldehyde or 3-o-methylglucose on the other hand cause different metabolic states in pancreatic islets.

ISSN:1663-2818    

DOI:10.1159/000178725

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

The African cichlid fish Haplochromis burtoni shows specific behavioral responses to the intramuscular injection of testosterone. Approaching and attacking were significantly increased by injections, while six other observed behaviors remained unchanged. The results suggest that the injected testosterone affected the control of both sexual and agonistic behaviors.

ISSN:1663-2818    

DOI:10.1159/000178726

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

With the structural characterization of the hypothalamic hormones, luteinizing hormone-releasing hormone (LH-RH), thyrotrophin-releasing hormone (TRH), melanocyt-stimulating hormone release-inhibiting hormone (MIH), and growth hormone release-inhibiting hormone, (GH-RIH or somatostatin), it has been possible to investigate their enzymic inactivation by peptidases which are present at various sites in the body. Enzymes may play an important part in the control of polypeptide hormone levels and the peptidases acting on these four hypothalamic hormones may regulate the amount of TRH, LH-RH, MIH and somatostatin released from the hypothalamus, or their action at the level of the pituitary and their removal from the circulation. By studying the peptidase enzymes, further information may be obtained on the physiological mechanisms controlling the secretion and actions of hypothalamic hormones, as well as on the design of analogues with increased or competitive activity.

ISSN:1663-2818    

DOI:10.1159/000178727

出版商:S. Karger AG    

年代:1976

数据来源: Karger

ISSN:1663-2818    

DOI:10.1159/000178728

出版商:S. Karger AG    

年代:1976

数据来源: Karger