ISSN:1663-2818    

DOI:10.1159/000178679

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Prolactin activity was measured in serum, urine and milk using a specific human prolactin radioimmunoassay (RIA). Serum, urine and milk were parallel with the human prolactin standard in the RIA. There was no correlation between serum prolactin levels and urinary prolactin activity. Dialysis of urine samples resulted in complete loss of human prolactin activity while the addition of human prolactin to the urine resulted in the recovery of over 50 % of the hormone after dialysis. Thus it was concluded that prolactin is not present in urine. In additional experiments it was observed that the RIA prolactin activity in urine was significantly correlated with the osmolality of the urine and that Na+ and K+ were contributory elements. On the other hand, prolactin was found in human milk and correlated well with the expected serum levels of this hormone. This latter finding is interesting because prolactin receptors have been shown to exist on the serosal side of the mammary epithelial cells. The presence of prolactin in milk suggests the possibility of other sites of action for this hormone in addition to the cell membrane.

ISSN:1663-2818    

DOI:10.1159/000178680

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

A 35-year-old woman experienced tetanic symptoms when treated with chorionic gonadotrophins or estrogenic oral contraceptives. Persistent hypocalcemia was found, with hyperphosphatemia, normal renal function and low normal plasma parathyroid hormone (PTH), all consistent with idiopathic hypoparathyroidism. During EDTA infusion, no PTH response was measured with a predominantly anti-NH2 -terminal antiserum, but a normal response was found with a predominantly anti-COOH-terminal antiserum. This supposes secretion of an immunologically abnormal and biologically ineffective PTH. Oral administration of ethinyl estradiol caused an impressive hypocalcemia with tetanic symptoms. Estrogens might, therefore, inhibit bone resorption by a specific action on bone, and not by antagonizing the action of PTH.

ISSN:1663-2818    

DOI:10.1159/000178681

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

In vitro transformation of precursors to androgens and oestrogens was studied in breast tissues from 7 phenotypic males with gynaecomastia and 3 normal females. All the tissues studied showed formation of dihydrotestosterone and oestrogens, thus demonstrating the presence of 5α-reductase and aromatizing enzymes. The results on the values of urinary oestrogens before and after surgical removal of the breast tissue substantiate the biosynthetic potential of gynaecomastic tissue. The aetiological significance of these findings vis-à-vis gynaecomastia is discusse

ISSN:1663-2818    

DOI:10.1159/000178682

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

In vitro biosynthesis of gonadal steroids from dehydroepiandrosterone was studied in isolated and in socially reared male and female rats. Acetone-dried powder of gonadal tissue incubated with dehydroepiandrosterone-4–14C yielded androstenedione, androst-5-ene-3β, 17β-diol, 11β-hydroxyandrostenedione and testosterone. In the male, conversion to androstenedione was significantly increased after isolation and conversion to androst-5-ene-3β, 17β-diol was significantly lowered. In the female, conversion to androstenedione and androstenediol was significantly lowered by isolation. Testosterone and 11β-hydroxyandrostenedione were not affected by isolation. Gonadal tissue of isolated and of socially reared male and female rats metabolizes dehydroepiandrosterone in a different way. These findings support the view that the conditions of housing affect the production of sex s

ISSN:1663-2818    

DOI:10.1159/000178683

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

A significant elevation in both luteinizing hormone (LH) and prolactin release was observed in the culture medium of hemipituitaries from castrated estrogen-progesterone (EP) primed female rats incubated for 5 h with arginine vasotocin (AVT) and luteinizing hormone-releasing hormone (LRH) compared to corresponding halves incubated with LRH alone. However, AVT alone did not significantly alter the discharge of LH or prolactin from hemipituitaries of EP-treated rats in vitro. Arginine vasopressin, a natural analogue of AVT, inhibited prolactin release using this same model system. Normal male rat hemipituitaries incubated with AVT released significantly more LH and prolactin into the culture medium than did their corresponding halves. A log-dose response curve indicated that any dose from 100 ng to 10 µg AVT significantly promoted prolactin release. However, the terminal tripeptide of AVT, Pro-Arg-Gly(NH2), failed to modify the discharge of LH or prolactin into the culture medium

ISSN:1663-2818    

DOI:10.1159/000178684

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

The influence of subcutaneous implants of melatonin on reproductive organ growth in neonatally testosterone propionate-(TP)-treated, blinded rats was investigated. The testes and accessory sex organs of rats that were TP-treated and blinded grew significantly slower than those of intact control rats. Either treatment of animals with melatonin or pinealectomy partially restored growth of the reproductive organs. In that the effects of melatonin treatment were similar to those of pinealectomy in this experiment model, it is speculated that melatonin may not be the principal pineal antigonadotrophic substance in the male rat.

ISSN:1663-2818    

DOI:10.1159/000178685

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

The recently ruptured follicles of the avian ovaries were found to contain an oxytocic substance. The substance was found to be heat-labile, nondialyzable and not extractable by lipid solvents. The crude homogenate stimulated the frequency and amplitude of the chicken infundibulum, uterus and uterovaginal junction, if they were taken from hens 2 h before predicted oviposition. The homogenate was found to induce premature oviposition and to stimulate the uterine contractions of rats treated with progesterone. Uterine tissues taken from estrogen-treated rats either did not respond to the homogenate or were inhibited. Addition of phenoxybenzamine or propanolol did not inhibit the stimulatory effect of the homogenate. It is possible that this factor might be involved in regulating oviposition in the hen.

ISSN:1663-2818    

DOI:10.1159/000178686

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

In vitro experiments were carried out in which [4–14C]oestradiol-17β was incubated with a culture from caecal content from adult male rats at 37°C in an atmosphere of nitrogen. Oestrone was identified as the only certain metabolite. Other metabolites, if present, were quantitatively unimportant. The conversion of oestradiol-17β to oestrone was estimated to be 22

ISSN:1663-2818    

DOI:10.1159/000178687

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Synthetic LH-RH (0.75 and 2.5 µg/animal) was administered to mature intact and castrated female rabbits. The animals were injected for 3 consecutive days with either 40 µg estradiol benzoate (EB) dissolved in 0.5 ml propylene glycol 60 %, water 40 % or with the solvent alone. LH-RH was injected i.v. on the 4th day. In intact rabbits EB priming increased the pituitary LH response while LH basal levels were lowered. In the unprimed castrated rabbits, basal FSH and LH levels and the cumulative responses to LH-RH were higher than in intact control animals; EB priming lowered basal LH levels and cumulative responses to the values of intact control rabbits while both basal FSH levels and the cumulative responses were less influenced by the treatment. It is concluded that estrogen acts at both hypothalamic and pituitary levels to modify the LH responses to endogenous LH-RH, and that the complete inhibition of FSH hypersecretion in the ovariectomized rabbit probably needs another ovarian facto

ISSN:1663-2818    

DOI:10.1159/000178688

出版商:S. Karger AG    

年代:1975

数据来源: Karger