摘要:

Sprague-Dawley rats were treated with 10 µg/g b.w. thyroxine on days 8, 9 and 10 of life. This treatment had no effect on the development of the female diurnalpattern of plasma corticosterone or on the time of vaginal opening. Treated females cyclednormally and they showed compensatory hypertrophy (CH) of ovaries comparable tothat of vehicle-treated controls. Treated males responded to a combined ether-hemorrhagestress, as did controls, and they exhibited normal adrenal CH. Both treated males andfemales had lower body weights and reduced endocrine organ weights on day 49 of life

ISSN:0028-3835    

DOI:10.1159/000122704

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

The effect of various doses of LRF on pituitary LH and FSH release was examined in castrated adult male hamsters with different photoperiodic histories. Gonadotropin (Gn) release in response to LRF was independent of whether the animals had been exposed to a photostimulatory (LD 14:10) or a nonstimulatory (LD 6:18) light cycle for 60 days following castration. The lowest dose that caused a significant increase in serum Gns was 10 ng LRF/100 g b.w. for LH and 50 ng LRF/100 g b.w. for FSH. These results indicate that photoperiod, which is well known to exert major effects on the reproductive system of the golden hamster, does not do so by directly altering the responsiveness of the pituitary gland to hypothalamic Gn-releasing factor.

ISSN:0028-3835    

DOI:10.1159/000122705

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

In order to check the hypothesis of an identity of dopamine (DA) and prolactin inhibiting activity (PIF), their subcellular distribution was studied in the mediobasal hypothalamus (MBH) and the striatum, which served as a control structure. PIF was tested both in vivo and on pituitary incubates. Fractions were also assayed after adsorption of their catecholamine content on alumina, as well as in presence of haloperidol or alpha-flupentixol, potent DA receptor inhibitors. In the MBH, PIF was evenly distributed in the 17,000 g supernatant (S2) and in the crude mitochondrial fraction (P2), which contains synaptosomes. PIF activity was completely removed by alumina adsorption of S2, but not of P2 in spite of an over 99.9% elimination of DA. In contrast, striatal PIF activity was detected only in P2, and disappeared completely upon alumina adsorption, thus indicating that, in this structure, it is entirely due to DA. Addition of haloperidol (10–5 M) or alpha-flupentixol (10–6M) reduced PIF activity of crude MBH homogenates, but no longer affected it after alumina adsorption. Quantitative studies suggest that only half of the total MBH PIF activity is accounted for by DA. It is concluded that the MBH contains dopamine-free PIF, which, as already shown for several other neurohormones, is exclusively distributed in nerve-endi

ISSN:0028-3835    

DOI:10.1159/000122759

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Previous experiments from this laboratory using complete hypothalamic deafferentation have demonstrated that the adrenocortical discharge following olfactory stimulation is essentially mediated by neural pathways. In order to identify the neural afferents and the hypothalamic areas involved, this response was studied in rats with anterior (AD) and posterior (PD) partial hypothalamic deafferentations as well as in animals with bilateral lesions in the ventrolateral medial forebrain bundle (VMFB) and the gemini region (GR) in the hypothalamus. While rats with PD had a normal adrenocortical response to odor stimulation, this was completely inhibited in animals with AD and partially reduced in VMFB and GR lesioned rats. These data would indicate that the adrenocortical response following olfactory stimulation is mediated by anterior afferents to the hypothalamus and involves the VMFB and GR.

ISSN:0028-3835    

DOI:10.1159/000122706

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Morphologic and hormonal changes, induced by combined ablation of a thyroid lobe, one adrenal and one ovary, were studied over a 15-day period in rats, some of whom were subjected to 8 h of daily immobilization. The compensatory hypertrophy (CH) of the contralateral glands in non-stressed animals was associated with a significant increase in the plasma levels of LH (from the 1st to the 10th day), prolactin (PRL, from the 3rd to the 6th day), FSH (on the 3rd day) and corticosterone (from the 6th to the 15th day), whereas GH titers were not altered. Immobilization for 1, 3, 6, 10 or 15 days inhibited the b.w. gain, induced involution of the thymus, enhanced compensatory enlargement of the adrenal, and blocked the CH of the ovary and, to a lesser degree, of the thyroid. This chronic stressor produced a marked rise in plasma corticosterone, antagonized the surge of PRL, FSH and LH, and decreased the plasma levels of GH. On the basis of these morphologic and hormonal variations, it appears that severe chronic stress in hemi-thyroidectomized-adrenalectomized-ovariectomized animals further increases the ACTH response but antagonizes the increased secretion of the other pituitary hormones.

ISSN:0028-3835    

DOI:10.1159/000122707

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

[3H]-Thyroliberin (TRH) has been previously shown to enter its target GH3 cells. Intracellular [3H]-TRH was found chemically unmodified and associated to organites, cytosol and nucleus. We studied the [3H]-TRH binding capacity of a highly purified nuclear fraction isolated by an original procedure from GH3 cells. The nuclei still presented their double nuclear envelope. They are able to bind [3H]-TRH to the same extent as nuclei isolated from GH3 cells previously exposed to [3H]-TRH. The equilibrium of binding was reached after 2–5 min incubation at 25° or 35°C. The binding is stable at 4°C and partially (50%) dissociated within 15 min at 25°C. 50% of the binding was inhibited by large excess of unlabelled TRH. Nuclei obtained from a variant GH3 cell which has lost its responsiveness to TRH presented only the noncompetitive binding compartment. The binding was found dose dependent and not saturable. Two apparent dissociation constants were evaluated: 1.5–2.5 × 10–8 M and 2.10–6 M, respectively, for high and low doses of [3H]-TRH. The first one was identical to that previously found for intact GH3 cells. The present data show the existence of specific nuclear binding sites for TRH, establish their characteristics and suggest a possible nuclear site of action for that pep

ISSN:0028-3835    

DOI:10.1159/000122760

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Six patients with idiopathic isolated gonadotropin deficiency (IGD) were treated with 100 µg LH-RH s.c. 3 times daily, leading to subnormal increases of serum gonadotropin (Gn) and testosterone (T) levels, and promoting puberty from stage I to stage II–III of Tanner. S.c. administration of 100 µg of the more potent and longer-lasting analogue 6-D-Leu-10-Des-Gly-ethylamide-LH-RH induced LH and FSH rises after the very first application in these patients for more than 12 h. However, long-term therapy with the analogue (100 µg s.c./day) did not improve hypogonadism. Paradoxically, on daily treatment (8 patients) with 6-D-Leu-10-Des-Gly-ethylamide-LH-RH the FSH serum levels fell after 1 week and the LH levels after 8 weeks of treat

ISSN:0028-3835    

DOI:10.1159/000122708

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

The influence of the hypothalamus on the development of the anterior pituitary cells was studied in normal and anencephalic human fetuses. An immunocytological method was applied to study the quantitative evolution of the size of the cells during gestation. The somatotropic and corticotropic cells appeared at the end of the 2nd month of gestation. After the 3rd month of gestation their normal development required the presence of brain. The results suggest that hypothalamic factors are needed for the normal development of cells containing these pituitary hormones.

ISSN:0028-3835    

DOI:10.1159/000122709

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

An acid extract of ovine pineal tissue inhibited luteinising hormone (LH) release in ovariectomized oestrogen and progesterone (OEP) pre-treated female rats, and did not exhibit any LH-RH-like immunoreactivity in vitro.

ISSN:0028-3835    

DOI:10.1159/000122710

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Thyrotropin-releasing hormone (TRH) has been reported to stimulate the release of melanocyte-stimulating hormone (MSH) from the pars intermedia (PI) of Rana esculenta. To test its effect on the rat PI, acutely dispersed rat PI cells, as well as whole nervosa-intermedias (NI), were incubated with synthetic TRH, from 10–10-10–4 M. TRH did not alter the release of either MSH or adrenocorticotropic hormone (AC

ISSN:0028-3835    

DOI:10.1159/000122761

出版商:S. Karger AG    

年代:1977

数据来源: Karger