摘要:

The effect of 2-Br-α-ergocryptine (EC) on the synthetic and releasing activities of prolactin and growth hormone (GH) in the anterior pituitaries of rats has been studied. Wistar-Imamichi female rats were injected intraperitoneally with 100 µg of EC before 1, 6 or 8 h of sacrifice and killed at 3:00 p.m. on the proestrous day. Anterior pituitary was incubated in vitro to determine the incorporation of 14C-leucine into hormones. The release of prolactin was completely depressed by EC, but not its synthesis at all. The serum prolactin levels were highly significantly lower in the EC-treated groups than in the control. Neither synthesis nor release of GH were affected at all by E

ISSN:1663-2818    

DOI:10.1159/000178613

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

The distribution of 125I-labeled ovine prolactin was studied in mice and rats after an intravenous injection by using whole-body and microautoradiography. In the whole-body autoradiography the labeled hormone rapidly accumulated in liver and kidney, but additionally some labeling was noted in the ventral prostate, seminal vesicles and mammary glands. In microautoradiography the grains were localized almost exclusively in the proximal tubular cells of the kidney. In the liver the labeling was more diffuse over both the parenhymal and the KupfTer cells. In the ovary the labeling was weak and mainly localized over the corpus luteum. Only minor differences were encountered in the intensity of labeling during the sexual cycle, pregnancy and lactation. The mammary epithelium showed some labeling during pregnancy and lactation. In the testis the grains were localized around the Leydig cells with no indication of tubular distribution. The ventral prostate showed a clear labeling of the epithelium. With increasing time after the injections the grains were rapidly localized toward the prostatic acinar lumen. Only a weak labeling of the preputial glands and seminal vesicles was observed. The role of prolactin as a synergist in the hormonal control of a variety of target organs was discussed.

ISSN:1663-2818    

DOI:10.1159/000178614

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

The effect of melatonin (100 µg/ml) on basal and glucose-induced insulin secretion was investigated using micro-dissected pancreatic islets of obese hyper-glycaemic mice and their normal lean littermates, and pieces of rat pancreas. Melatonin had no significant effect on basal insulin secretion from both normal and obese mouse islets, but significantly reduced basal insulin secretion from pieces of rat pancreas. However, glucose-induced insulin secretion was significantly inhibited by melatonin in both preparations. A constant infusion of melatonin into rats undergoing intravenous glucose tolerance tests did not alter blood sugar levels and produced only a marginal decrease in plasma insulin levels. It is suggested that melatonin may be involved in the monoaminergic regulation of insulin secretion

ISSN:1663-2818    

DOI:10.1159/000178615

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

Three days after a single injection of streptozotocin rats showed hyperglycemia, hyperketonemia and hypoinsulinemia. Body and liver weights were reduced and the concentration of DNA-P, phospholipid-P, proteins and acetyl-CoA in the liver was augmented, while the concentration of glycogen and citric acid in these animals compared with the controls which did not receive the drug was decreased. After 48 h starvation, blood glucose remained higher in the streptozotocin-treated animals, while circulating ketones and insulin were not different from those in the controls. With the exception of body and liver weights, which were lower, and of liver DNA-P, which was higher than when fed, neither of the other parameters studied in the streptozotocin treated animals changed with fasting, while the response in the controls was normal. The incapacity of increasing the postprandial insulin secretion in these animals may contribute to the metabolic alterations found in the fed state.

ISSN:1663-2818    

DOI:10.1159/000178616

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

Because of the limitations of existing methods for estimation of cortisol production rate (CPR), a micromodification of a previously reported technique based on measurement of the specific activity of cortisol after a single injection of tracer cortisol was evaluated. The highest CPR’s were found in thyrotoxicosis, Cushing’s disease, and diabetic ketoacidosis. Correlation with CPR based on the specific activity of urinary metabolites was good only in those instances in which circulating cortisol concentrations varied by less than 30% during the 2 hours after injection of the tra

ISSN:1663-2818    

DOI:10.1159/000178617

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

An aldosterone-secreting adrenocortical adenoma was removed by surgery from a 15-year-old boy who exhibited signs characteristic of Conn’s syndrome including hypertension, potassium depletion and increased aldosterone production rate. The neoplasm was found to consist mainly of clear cells by light microscopy. Ultrastructural investigations revealed that the neoplasm was composed chiefly of fasciculata cells characterized by mitochondria with vesicular cristae. Some mitochondria, however, possessed tubular cristae reminiscent of those occurring in zona glomerulosa cells. It appears that mitochondria are not rigidly static constituents of cells but they can change constantly in order to satisfy variations in functional need. Other ultrastructural features included accumulation of lysosomes and lipofuscin granules, an increase of the rough-surfaced endoplasmic reticulum membranes, lipid depletion, focal hypertrophy and dilatation of the Golgi sacculi, and a pronounced hypertrophy of the smooth-surfaced endoplasmic reticulum. The latter alterations were thought to represent the fine structural manifestations of enhanced cellular activity associated with increased production of aldosteron

ISSN:1663-2818    

DOI:10.1159/000178618

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

Catecholamine excretion, cholesterol, triglycerides, free fatty acids (FFA) and plasma 11-OH corticoids were measured in 18 normal workers of an aircraft factory exposed to turbine noise for 3 h. Blood pressure and pulse frequency were also registered. In 72% of the subjects, marked elevations of catecholamine excretion were found, correlating fairly well with increases of cholesterol, FFA, blood pressure and pulse frequency. Surprisingly, after 3 h of noise exposure, the plasma 11-OH corticoid mean value was slightly lower than the one of the early morning in resting conditions; this could be ascribed to the pronounced midday drop of plasma corticoids, characteristic of the circadian cortisol variation. This could counteract the moderate corticoadrenal stimulation caused by the noise stress. The blood pressure and plasma lipid elevation found in these workers might be detrimental to personnel suffering from atherosclerosis or other vascular pathology.

ISSN:1663-2818    

DOI:10.1159/000178619

出版商:S. Karger AG    

年代:1974

数据来源: Karger