VARIATIONS IN PLASMA ALDOSTERONE AND PLASMA RENIN ACTIVITY THROUGHOUT THE MENSTRUAL CYCLE, WITH SPECIAL REFERENCE TO THE PRE-OVULATORY PERIOD

1973 ◽  
Vol 73 (3) ◽  
pp. 499-508 ◽  
Author(s):  
Johan A. Sundsfjord ◽  
A. Aakvaag

ABSTRACT The day to day variations in plasma aldosterone and plasma renin activity throughout the menstrual cycle have been investigated in healthy young women. A sensitive and specific radioimmunoassay for the measurement of plasma aldosterone is described. The actual hormone parameters have been correlated with fluctuations in plasma oestradiol and progesterone, and LH has been measured for the determination of time of ovulation. Plasma renin activity and plasma aldosterone gradually increased two to four times from the early follicular to the mid-luteal phase, in accordance with earlier observations. In one woman using a beta adrenergic blocking agent plasma renin activity rose only slightly, whereas a normal rise in plasma aldosterone was noted. Another woman became pregnant during the cycle investigated. In this subject neither plasma renin activity nor plasma aldosterone decreased at the end of the cycle. Plasma aldosterone was almost doubled on the pre-ovulatory day, as compared with the early follicular phase, whereas no significant change in plasma renin activity or plasma renin substrate was found. The cause of this pre-ovulatory increase in plasma aldosterone is not known.

1972 ◽  
Vol 71 (3) ◽  
pp. 519-529 ◽  
Author(s):  
Johan A. Sundsfjord ◽  
A. Aakvaag

ABSTRACT The relative importance of endogenous progesterone and oestrogens on the rise in plasma renin activity and urinary aldosterone excretion in the luteal phase of the menstrual cycle has been investigated in two groups of young women. One group (luteal group) had plasma progesterone levels of 7–19.5 ng/ml (mean 12.3; sem 1.3) in the second half of the cycle. The other group (luteal failure group) had plasma progesterone levels of 1.5–3.0 ng/ml, (mean 2.1; sem 0.16), on the corresponding days in the second half of the cycle. The plasma oestrogen levels and the oestriol excretion did not differ between the groups at any stage of the cycle. In the luteal group the normal increase in plasma progesterone and plasma oestrogens and in oestriol excretion was accompanied by a doubling in plasma renin activity and urinary aldosterone excretion, whereas the plasma renin substrate levels did not change significantly. In the luteal failure group, no significant increase was found in either plasma renin activity or in urinary aldosterone excretion, in spite of the unchanged plasma oestrogen levels and oestriol excretion. In this group too the plasma renin substrate levels showed no change from the first to the second half of the cycle. It is concluded that the rise in plasma renin activity, plasma angiotensin II concentration and urinary aldosterone excretion in the luteal phase of the normal menstrual cycle is caused by increased progesterone production.


1999 ◽  
Vol 162 (1) ◽  
pp. 21-29 ◽  
Author(s):  
P Vendeira ◽  
D Pignatelli ◽  
D Neves ◽  
MM Magalhaes ◽  
MC Magalhaes ◽  
...  

Adrenocortical regeneration after adrenal autotransplantation provides a model for the study of local autocrine/paracrine mechanisms involved in the growth and differentiation of the adrenal cortex. To study the possible involvement of some growth factors, namely basic fibroblast growth factor (bFGF, FGF-2) and insulin-like growth factor I (IGF-I), in cell differentiation, immunohistochemical and ultrastructural studies were carried out on adrenal autotransplants in adult male rats. To distinguish between fasciculata and glomerulosa-like cells with accuracy, tissue sections were immunostained with IZAb, which recognizes the inner zone antigen (IZAg) present in fasciculata and reticularis cells but absent from the glomerulosa, and by electron microscopy. IGF-I-treated animals exhibited a clear glomerulosa-like zone that was devoid of IZAb immunostaining. In this outer subcapsular area, ultrastructural examination showed cells containing mitochondria with irregular cristae resembling those of the fetal or immature glomerulosa cells. In contrast, no significant morphological differences were observed in bFGF-treated animals when compared with those from saline-treated controls, in both of which, IZAb immunostaining occurred in almost all adrenocortical cells, with no clear zonation or glomerulosa, as seen in the intact animal. Plasma aldosterone and corticosterone concentrations were lower in autotransplanted control animals than in intact controls, although plasma renin activities were similar. IGF-I treatment significantly increased aldosterone concentrations, whereas corticosterone and plasma renin activity were reduced. bFGF infusion further reduced plasma aldosterone, although plasma renin activity and corticosterone were unaffected. These results suggest that the two growth factors have different effects on zonal differentiation and function in the autotransplanted gland. In particular, bFGF, by reducing glomerulosa function, appears partly to replicate the actions of ACTH in normal animals. In contrast, IGF-I enhances the glomerulosa secreting phenotype and diminishes that of the fasciculata/reticularis, possibly replicating the actions of angiotensin II or a low sodium diet.


1977 ◽  
Vol 43 (3) ◽  
pp. 421-424 ◽  
Author(s):  
J. R. Sutton ◽  
G. W. Viol ◽  
G. W. Gray ◽  
M. McFadden ◽  
P. M. Keane

Responses of plasma renin activity, plasma aldosterone, plasma cortisol, and plasma electrolyte concentration and urinary electrolyte and aldosterone excretion were studied in four men during hypoxic decompression to a stimulated altitude of 4,760 m in a pressure chamber. Three of the four subjects developed significant acute mountain sickness. Plasma sodium and potassium concentrations were unchanged. No significant change in plasma renin activity was observed, but values tended to fall. Plasma aldosterone concentration was depressed while plasma cortisol was elevated and diurnal variation lost. Urinary sodium excretion was unchanged, but urinary potassium and aldosterone excretion were decreased. The decrease in plasma and urinary aldosterone and urinary potassium in the absence of change in plasma renin activity or plasma potassium is of uncertain origin. It is unlikely to be due to a decrease in adrenocorticotropin secretion since plasma cortisol rose during the same time. None of the changes could be causally implicated in the development of acute mountain sickness although the increase in plasma cortisol was greatest in the most ill.


Hypertension ◽  
2020 ◽  
Vol 76 (2) ◽  
pp. 488-496 ◽  
Author(s):  
Zeng Guo ◽  
Marko Poglitsch ◽  
Diane Cowley ◽  
Oliver Domenig ◽  
Brett C. McWhinney ◽  
...  

The aldosterone/renin ratio (ARR) is currently considered the most reliable approach for case detection of primary aldosteronism (PA). ACE (Angiotensin-converting enzyme) inhibitors are known to raise renin and lower aldosterone levels, thereby causing false-negative ARR results. Because ACE inhibitors lower angiotensin II levels, we hypothesized that the aldosterone/equilibrium angiotensin II (eqAngII) ratio (AA2R) would remain elevated in PA. Receiver operating characteristic curve analysis involving 60 patients with PA and 40 patients without PA revealed that the AA2R was not inferior to the ARR in screening for PA. When using liquid chromatography-tandem mass spectrometry to measure plasma aldosterone concentration, the predicted optimal AA2R cutoff for PA screening was 8.3 (pmol/L)/(pmol/L). We then compared the diagnostic performance of the AA2R with the ARR among 25 patients with PA administered ramipril (5 mg/day) for 2 weeks. Compared with basally, plasma levels of equilibrium angiotensin I (eqAngI) and direct renin concentration increased significantly ( P <0.01 or P <0.05) after ramipril treatment, whereas eqAngII and ACE activity (eqAngII/eqAngI) decreased significantly ( P <0.01). The changes of plasma renin activity and plasma aldosterone concentration in the current study were not significant. On day 14, 4 patients displayed false-negative results using ARR_direct renin concentration (plasma aldosterone concentration/direct renin concentration), 3 of whom also showed false-negative ARR_plasma renin activity (plasma aldosterone concentration/plasma renin activity). On day 15, 2 patients still demonstrated false-negative ARR_plasma renin activity, one of whom also showed a false-negative ARR_direct renin concentration. No false-negative AA2R results were observed on either day 14 or 15. In conclusion, compared with ARR which can be affected by ACE inhibitors causing false-negative screening results, the AA2R seems to be superior in detecting PA among subjects receiving ACE inhibitors.


1991 ◽  
Vol 37 (10) ◽  
pp. 1811-1819 ◽  
Author(s):  
J E Sealey

Abstract Sensitivity and accuracy are essential features of an assay of plasma renin activity (PRA) because the normal concentration of PRA is only 1 pmol/L, and subnormal concentrations have diagnostic relevance. Conditions for blood collection need to be standardized but the conditions are not difficult for outpatients. For routine diagnostic purposes blood should be collected from ambulatory (ideally, untreated) patients on moderate sodium intake. To avoid irreversible cryoactivation of plasma prorenin (which is present in 10-fold greater concentrations than renin), samples should be processed at room temperature and stored completely frozen. Cryoactivation occurs when plasma is liquid at temperatures less than 6 degrees C. PRA is commonly measured with an enzyme kinetic assay in which angiotensin I (Ang I) is formed by the reaction of plasma renin with endogenous renin substrate (angiotensinogen). The Ang I so formed is measured by RIA; results are expressed as an hourly rate (micrograms/L formed per hour). This method, which is provided by most commercial kits, has the potential for unlimited sensitivity because the step for Ang I generation can be prolonged as long as necessary, so that enough Ang I forms to be measured accurately. Unfortunately, that sensitivity is not always exploited. Dilution of plasma during pH adjustment should be kept to a minimum. The Ang I generation step should last at least 3 h. The step should last 18 h for samples with PRA less than 1.0 micrograms/L per hour, to eliminate the errors inherent in the measurement and subtraction of immunoreactive Ang I in the untreated plasma (blank subtraction). These changes actually simplify PRA measurements because they eliminate the need for ice in the clinic and reduce by almost half the number of samples to be assayed by RIA. I also describe the method for measurement of plasma prorenin, which may be an important marker for patients with diabetes mellitus who subsequently develop vascular complications.


2016 ◽  
Vol 34 ◽  
pp. e333-e334
Author(s):  
F. Giulietti ◽  
F. Spannella ◽  
E. Borioni ◽  
F.E. Lombardi ◽  
L. Landi ◽  
...  

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