摘要:

The effect of intramuscular injection of 1,000 mg medroxyprogesterone acetate on plasma renin activity and antidiuretic hormone was studied in 9 postmenopausal women. There were no significant differences in the plasma renin activity and antidiuretic hormone values before and after the injection. 8 postmenopausal women received d-norgestrel (0.180 mg/day) during a 3-week period. The therapy had no effect on plasma renin activity, antidiuretic hormone, or aldosterone excretion.

ISSN:1663-2818    

DOI:10.1159/000179429

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

To examine the effects of reducing sodium intake upon the renin-angioten-sin-aldosterone system (RAAS), 5 healthy men and 5 healthy women, 17-37 years old, living under standardized conditions, were sampled around the clock, once on habitual and once on restricted sodium intake. Plasma renin activity (PRA), aldosterone (PA) and cortisol (PC) were determined by radioimmunoassay. All three variables were found to exhibit a statistically significant circadian rhythm, both on habitual and restricted salt intake. After salt restriction, an increase in midline-estimating statistic of rhythm (mesor) of PRA and PA, but not of PC, was observed. The acrophase (an estimate of the time of high values) for PC lagged behind that for PRA and PA. This difference in acrophase was of specially high statistical significance when subjects were on a sodium-restricted diet. These results demonstrate the importance of inferential statistical so-called rhythmometric methods: parameters such as the acrophase can also be used for the assessment of novel effects and for a quantification in time. The derivation of confidence intervals for each rhythm parameter allows one to verify that a given variable exhibits values bracketing an average not only between a higher and a lower, but also between an earlier and a later limit. Changes that may involve only the acrophase, such as a lead or lag, as here noted, are then detected and are of factual as well as methodological interest.

ISSN:1663-2818    

DOI:10.1159/000179430

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

Investigations were carried out on the behavior of 18-hydroxy-11-deoxycorticosterone (18-OH-DOC) in essential hypertension (EH) under exogenous administration of synthetic ACTH and insulin. 40 stable EH patients and 21 normal subjects were included in the study. The increase (12-fold basal values) in plasma 18-OH-DOC in normal subjects under Tetracosactide was significantly higher than cortisol (4-fold basal values). Furthermore, insulin hypoglycemia increased 18-OH-DOC levels 5-fold, whilst basal values of cortisol were increased 2-fold. An increase in 18-OH-DOC and cortisol was also observed in EH patients: in the subgroups with normal and low plasma renin activity, however, the rise in these two steroids was significantly lower than that in normal subjects both under Tetracosactide and insulin. No significant hormonal modifications were observed after furosemide administration either in the normal subjects or in the EH patients. 18-OH-DOC by itself does not, therefore, appear to play a pathogenetic role in EH.

ISSN:1663-2818    

DOI:10.1159/000179431

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

Following four equally spaced injections (at 12-hour intervals) of pentagastrin (250 µg/kg) to fasted rats the incorporation of [3H]-thymidine into gastric mucosal DNA in vivo and in vitro was significantly increased by 30 and 58%, respectively, when compared with the corresponding saline control. Pentagastrin treatments also caused a significant 50% enhancement in gastric mucosal thymidine kinase activity. It is suggested that the hormone-mediated stimulation in thymidine kinase activity may, in part be due to the presence of a physiological activator for the enzyme in the tissue

ISSN:1663-2818    

DOI:10.1159/000179432

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

After intravenous injection of 125I-ACTH 1-24into rats, the highest concentration of l25I was found in kidneys, adrenal, and liver. Addition of 5- and 30-fold excess unlabelled ACTH reduced the uptake of 125I by 50 and 68%, respectively, indicating that the adrenal uptake was specific. Pretreatment with dexamethasone decreased the adrenal uptake of 125I and caused adrenal atrophy. Chronic ACTH treatment increased the size of the adrenals, but did not affect the adrenal uptake of 125I. These experiments demonstrate selective uptake of 125I by the adrenals after administration of 125I-ACTH1-24.

ISSN:1663-2818    

DOI:10.1159/000179433

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

The proposition that rat prolactin has an intrinsic antidiuretic activity was examined using a conscious rat model (Brattleboro homozygotes, DI rats) which does not appear to produce arginine vasopressin (AVP). A preparation of rat prolactin obtained from NIAMDD, rat prolactin Bl, produced a prompt antidiuresis when administered intravenously to these animals. Prolactin Bl was found to contain 150ng of AVP/mg protein by RIA. All of the measurable AVP was removed from prolactin Bl by polyacrylamide gel electrophoresis and the electrophoresed prolactin was completely devoid of any antidiuretic activity. Addition of synthetic AVP to electrophoresed prolactin in an amount equivalent to the AVP contamination of prolactin B1 completely restored the originally observed antidiuretic activity. Synthetic AVP given alone produced a similar antidiuresis, but in the presence of electrophoresed prolactin these effects were produced by much smaller amounts of AVP. We believe that our data demonstrate that rat prolactin has no intrinsic antidiuretic activity, and that the antidiuretic activity associated with different prolactin preparations could be entirely due to their contamination with AVP. The data also show that the presence of prolactin enhanced by about five times the antidiuretic activity of AVP.

ISSN:1663-2818    

DOI:10.1159/000179434

出版商:S. Karger AG    

年代:1981

数据来源: Karger