摘要:

The binding capacity for estradiol in the cytosol and nucleus of the rat posterior hypophysis was demonstrated in vitro. The maximal 3H-estradiol binding took place at 37°C in both fractions; but when time experiments were performed, the most binding occurred at 30 min in the cytosol and at 90 min in the nucleus. Administering exogenous estradiol to spayed rats shifted the site of maximal binding from the posterior hypophysis’ cytosol to the nucleus. Both fractions showed a low capacity for 3H-estradiol binding; we studied the presence of a macromolecular component(s) that bind(s) estradiol with high affinity in the cytosol. The number of binding sites in the whole posterior hypophysis was determined in spayed and estradiol-treated rats. In the latter group, the protein content of the posterior hypophysis increas

ISSN:0028-3835    

DOI:10.1159/000122440

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Sexual behavior and elevation of gonadal steroids were induced in both male and female New Zealand white rabbits following injection of synthetic β(1–24) ACTH into the lateral cerebral ventricle. In blood assays collected by cardiac puncture, testosterone, progesterone and corticosterone were all increased above both resting levels and samples were taken after a control intraventricular injection of physiological saline. Parallel increases of plasma LH were also demonstrated. The results were interpreted to indicate that intraventricular ACTH, through LH release, influences sex hormone levels and sexual behavior by acting ‘centrally’, probably within the hypoth

ISSN:0028-3835    

DOI:10.1159/000122441

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Rathke’s pouch tissue, from rat embryos of 11–15 days’ gestation, was microsurgically removed and transplanted into the hypothalamus of hypophysectomized adult females. The hosts were sacrificed 4 weeks later; brain and target organs were preserved for histological examination. Plasma samples were taken for the radioimmunoassay (RIA) of follicle stimulating hormone (FSH) and luteinizing hormone (LH). The implanted tissue invariably developed along certain lines. Undifferentiated primitive cells were found associated with nervous tissue, dense connective tissue, cartilage and glandular cells. In every age group, some implants became invasive, forming massive growths in the brain. These tumorous properties were principally associated (p < 0.05) with tissue from 12-day embryos. Pituitary primordia from all ages demonstrated the ability to develop into functional adenohypophyseal tissue. Target organ stimulation indicated a secretion of corti-cotropin, thyrotropin and somatotropin. FSH and/or LH were detected by RIA in the plasma of 61 % of the test animals. We suggest that this system offers unique opportunities for future investigations into the mechanisms that determine whether embryonic epithelial tissue will remain under normal growth control or will become tumorous or even canc

ISSN:0028-3835    

DOI:10.1159/000122442

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

The effect of 5 dopamìnergic drugs, 2-Br-α-ergocryptine (CB 154), L-dopa, 1-(2-pyrimidyl)-4-piperonylpiperazine (Piribedil), amantadine and 1,3-dimethyl-5-amino-adamantan (D 145), on human growth hormone levels (hGH) was studied in 38 acromegalîc subjects. Acute administration of CB 154 (2.5 mg p.o.) in 34 patients was followed by a significant and sustained fall in plasma hGH levels; in 19 cases (55.9%) the observed fall was clearly below the ± 2 SD of the mean GH changes present in the same subjects after placebo. In patients previously shown to be responsive to CB 154, significant GH falls were also present following the single administration of L-dopa (500 mg p.o.) (9 patients) and Piribedil (100 mg p.o.) (5 patients), although CB 154 exhibited a more frequent, striking (reduction of up to 1–2 ng/ml) and long-lasting (4 h more) effect. In contrast, amantadine (200 mg p.o.) or D 145 (20 or 50 mg p.o.) did not induce significant changes in hGH levels (7 patients). These results broaden and corroborate previous findings on the hGH-lowering effect of dopamìnergic stimulation in acromegaly. The possible reason(s) for the difference in hGH response with different dopamìnergic compounds is di

ISSN:0028-3835    

DOI:10.1159/000122443

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

The diuretic action of two new narcotic antagonists, oxiiorphan and butorphanol, was studied in rats heterozygous for hereditary hypothalamic diabetes insipidus. Both drugs caused a prompt increase in urine volume and a decrease in urine osmolality with an associated decrease in urinary ADH excretion. The effects appeared to be dose related and of short duration. Tolerance to butorphanol administration was evident on repeated daily injections. The diuretic effect was not associated with alteration in creatinine excretion, but butorphanol resulted in decreased osmolal, sodium and potassium excretion. Butorphanol prevented the expected rise in urine osmolality and ADH excretion due to 31 h of dehydration. Oxiiorphan did not interfere with the ability of administered ADH to cause an antidiuresis. The data indicate that these narcotic antagonists cause a diuresis by inhibiting ADH release from the neurohypophysis.

ISSN:0028-3835    

DOI:10.1159/000122444

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Both norepinephrine (NE) and its major metabolite, 3-methoxy-4-hydroxy-phenylglycol (MHPG), were assayed in rat hypothalamus during selected stages of pregnancy and lactation. No changes were observed in the concentration of either NE or MHPG at 5, 15 or 21 days’ gestation. However, within 8–15 h after parturition, the concentration of NE decreased sharply while that of MHPG showed a correspondingly sharp increase. The possible significance of such changes in hypothalamic catecholamine activity was considered in relation to parturition, postpartum estrus and onset of maternal behav

ISSN:0028-3835    

DOI:10.1159/000122445

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Implants of hydrocortisone acetate (HCA), cholesterol or empty tubing were placed in the hypothalamus of rats. Corticoid implants elevated serotonin levels in the basomedial hypothalamus compared to the other two groups, but norepinephrine levels were unchanged. Adrenal and serum corticosterone, as well as adrenal weight, were lower in animals with hydrocortisone implants. These data support the hypothesis that hypothalamic serotonin is involved in negative feedback control of adrenal steroid secretion. Biogenic amines in the medial hypothalamus were determined at 30 days in rats neonatally treated with HCA. Both norepinephrine and serotonin levels were elevated significantly in the treated group in comparison to controls, but dopamine levels failed to change.

ISSN:0028-3835    

DOI:10.1159/000122446

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

In dogs with hypothalamic lesions as well as in intact and hypophysectomized dogs, adrenal venous blood samples were collected and analyzed for 17-hydroxycorticosteroids (17-OHCS). In intact dogs a marked increase in adrenal 17-OHCS secretion was observed following the i.v. infusion of cyanide as well as after the i.v. injection of pilocarpine; this was completely abolished by hypophysectomy. The adrenocortical response to pilocarpine was markedly impaired and that to cyanide partially suppressed after lesioning of the anterior median eminence. However, after lesioning of the posterior median eminence, the adrenocortical secretory response to pilocarpine was almost the same as in intact dogs, whereas the response to cyanide was markedly impaired. Thus, a dissociation of adrenocortical secretory responses to cyanide and pilocarpine was demonstrated in dogs with hypothalamic lesions.

ISSN:0028-3835    

DOI:10.1159/000122447

出版商:S. Karger AG    

年代:1975

数据来源: Karger

ISSN:0028-3835    

DOI:10.1159/000122448

出版商:S. Karger AG    

年代:1975

数据来源: Karger