摘要:

The thyroid-stimulating antibody (TSAb) of Graves’ disease was shown to have a relatively constant pH on preparative isoelectric focusing; the fraction of pH 8.5–9.0 was maximal in thyroid-stimulating potency but inhibition of thyrotropin-binding (another property of Graves’ disease IgG) was most marked with pH 9.5–10.6 fraction. H and L chains of TSAb-IgG were separated and H original (Ho) was combined with L original (Lo) and with Bence Jones Lk and Lλ. Only HO + LO restored (minimal) bioactivity. Of isolated TSAb-IgGĸ and TSAb-IgGλ only IgGλ was thyroid stimulating. Sub-classes (IgG3 and IgG 1 + 2+4) of TSAb-IgG were prepared and with all of 6 sera TSAb was in IgG 1 + 2+4 with none in IgG3. These data combine to suggest restricted heterogeneity of this autoimmu

ISSN:1663-2818    

DOI:10.1159/000179266

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

16 female rabbits were actively immunized against testosterone (T). 9 of them conceived and gave birth to 89 neonates. In all neonatal plasma samples antibodies against T were detected. In the males the plasma T levels were elevated 1,000-fold. The testes of these animals were examined by means of morphometrical and biochemical methods. The results indicate increased stimulation of Leydig cells in fetuses exposed to antibodies against T, and suggest that even in the fetus a negative feedback is acting between testes and hypothalamo-pituitary system, which is interrupted by the antibodies which bind and inactivate T.

ISSN:1663-2818    

DOI:10.1159/000179267

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Anterior, dorsal, lateral, and ventral prostate lobe transplants derived from 12-week-old donor F344 rats were maintained in the cleared 5th mammary fat pads of 3-week-old testosterone propionate (TP)-implanted female and TP-implanted and unimplanted male syngeneic hosts for 12 posttransplantation weeks. Prostate transplants failed to survive in untreated female hosts. Implantation of TP pellets in male hosts resulted in an increase in the number of surviving transplants as well as in the ability of these transplants to biotransform testosterone-3H (T-3H) to its major radiometabolites (dihydrotestosterone-3H and androstanediol-3H) in vitro. TP implants + prolactin (50IU/kg daily i.p. injections for the 5 days prior to sacrifice) caused a marked increase in prostate weight and in epithelial secretory activity. Whereas the anterior, dorsal, and ventral lobe transplant showed acini with normal columnar epithelium and secretory activity, the epithelial cells in the lateral lobe transplants were often very irregular. In general, those prostate transplants which showed an ability to metabolize testosterone were also those exhibiting normal secretory epithelium.

ISSN:1663-2818    

DOI:10.1159/000179268

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Studies conducted in several laboratories have shown primate glucocorticoid secretion to occur episodically. In light of the methodological, as well as physiological importance of this finding, the present study was undertaken to determine whether the rat corticosteroid secretion also occurs episodically. Female rats were outfitted with chronic intravenous cannulas, and 1 week later 200 units of heparin were injected through the implanted cannula and blood samples (0.3–0.4 ml) were collected from each rat every 10 min for 3h during the morning (06.00–10.00 h) or during the afternoon (16.00–19.00 h) (lights on from 05.00 to 19.00 h). Plasma corticosterone levels in cannulated rats showed fluctuations indicative of episodic secretion. The pattern of plasma corticosterone levels was characterized by periodic rapid increases in hormone concentration during both the morning and afternoon sampling periods; the occurrence of these hormonal fluctuations did not have a characteristic frequency. When the data were grouped to obtain single morning and afternoon values, the AM-PM difference was significant (p < 0.005). Collectively, these data suggest that in the rat, adrenal corticosteroids are secreted episodi

ISSN:1663-2818    

DOI:10.1159/000179269

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Groups of 4–8 male rats weighing 350 g were injected with various doses of L-3,5,3´-triiodothyronine (T3, 1.25, 5 or 20 nmol kg-1) or L-thyroxine (T4, 5, 20 or 80 nmol kg-1) at 20, 60 or 180 min before i.v. injection of thyrotropin-releasing hormone (TRH, 10 nmol kg-1), a separate group being used for each dose and time interval, respectively. It was found that an interval of at least 20 min is necessary for a significant inhibition of plasma thyrotropin (TSH) response with 20 nmol T3 kg-1. When comparing the inhibitory activity of various doses of T3 and T4 at the same time interval, it was found that, on a molar basis, T3 appears to be about 4 times more potent than T4. Finally, the inhibitory effect of the highest dose of T4 used (i.e. 80 nmol kg-1) was found to be gradually overcome by 100 and 200 nmol TRH kg-1 administered 180 min later, while significantly less effect could be demonstrated after 20 nmol T3 kg-1 under the same conditions. When this finding is interpreted in terms of T4 to T3 conversion as a presumed essential step resulting in an inhibition of TSH release, it appears (since the inhibitory potency of the used dose of T3 was significantly higher than that of the 4 times higher molar dose of T4) that: (1) the conversion of much less than about 25% of administered T4 to T3 within 60–180 min may explain the observed effects; (2) a considerably higher dose of T4 should be used to exhibit the same inhibitory effects as the dose of T3

ISSN:1663-2818    

DOI:10.1159/000179270

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Aqueous extracts of frozen human corpora lutea were tested for the presence of an inhibitor of luteinizing hormone-receptor site binding (LHRBI) and for the subsequent effect on the stimulatory response of luteinizing hormone (LH) on progesterone synthesis by sheep ovarian cells. In the presence of human corpus luteum extract of normal menstrual cycle (30,000-g supernatant), the binding of 125I human chorionic gonadotrophin (hCG) to granulosa and luteal cells of sheep ovaries was markedly reduced, but the ability of rat testicular LH receptors to bind labelled hCG was less affected. However, extracts of corpora lutea of the first trimester of pregnancy appeared to be less inhibitory on the binding of LH/hCG to ovarian cells and had no effect on the binding of rat testicular cells compared to those of normal menstrual cycle. Addition of both extracts separately inhibited the LH-stimulated in vitro progesterone synthesis by granulosa cell cultures and by incubated sheep corpus luteum slices. These findings provide evidence for the presence of LHRBI in human corpus luteum.

ISSN:1663-2818    

DOI:10.1159/000179271

出版商:S. Karger AG    

年代:1980

数据来源: Karger

ISSN:1663-2818    

DOI:10.1159/000179272

出版商:S. Karger AG    

年代:1980

数据来源: Karger