1,721,317 research outputs found
Adrenomedullin and endocrine disorders
No full textAdrenomedullin (AM) is a recently discovered potent vasodilatory peptide, originally isolated in extracts of human pheochromocytoma, with activies including maintenance of cardiovascular and renal homeostasis through vasodilatation, diuresis and natriuresis. Human AM consists of 52 amino acids with a 6-member ring structure linked by a disulfide bond and amidated COOH terminal, which belongs to calcitonin gene-related peptide (CGRP) and amylin. The main sites of AM production are the lungs, vascular tissues (both endothelial and smooth muscle cells), heart, kidney, adrenal glands, pancreatic islets, placenta, anterior pituitary gland and gastrointestinal neuroendocrine system. Intravenous injection of AM increases blood flow predominantly in the tissues with the highest AM expression, suggesting that AM functions primarily as a paracrine/autocrine hormone, but it is also important as circulating hormone. The objective of this review is to analyze the evidence that AM may play a role in some endocrine disorders
Aldosterone-induced oxidative stress: a potential mechanism of aldosterone autonomy in primary aldosteronism
No full textStoria e gloria del Torino e dei tifosi granata tra musica, video arte e gioco del calcio
No full textSusanna Franchi, Carlo Crivelli, Lorenzo Letizia, Claudio Sala, Federico Mong
Towards a chronophysiology of circulating aldosterone
No full textThe physiology of aldosterone secretion has been prominently investigated by homeostatic studies on the levels of the steroid in plasma and/or urine. Aldosterone secretion is, however, arranged in a rhythmic fashion along the 24-hr cycle. The dynamics of aldosterone should thus be reanalyzed chronobiologically in order to gain further insight into the physiology of the hormone. Such a revisitation has been performed in the present study on four groups of clinically healthy volunteers categorized according to sex and age. Aldosterone has been assayed in the plasma of systemic venous blood six times a day (0600, 0800, 1200, 1800, 2000, 0000) in different conditions of physical activity and sodium intake. Time-qualified data have been analyzed by the single-cosinor method and then summarized by the population-mean cosinor procedure to quantify the circadian rhythms in their properties (mesor, amplitude, acrophase). Differences in rhythmometric parameters have been tested by a multivariate analysis for vectorial units. (Hotelling's T2 test). Cosinor analysis indicates that the dynamics of circulating aldosterone substantially changes in relation to posture. The habit of having a routine of diurnal activity leads the circadian rhythm of aldosterone to delay its acrophase from morning to afternoon. The postural shift of acrophase is essentially accompanied by an elevation in the 24-hr mean level. The restriction of salt intake is associated with an increase in mesor; the temporal localization of the circadian crest shows, however, a very high stability. Sex is not characterized by significant differences in the 24-hr patterns of aldosterone in the sense that young males and females show substantially identical time-qualified curves and circadian parameters. Increasing age until the seventh decade in life is responsible for changes mainly in 24-hr mean levels with a slight modification in amplitude. Such a chronophysiology for circulating aldosterone related to the motor-rest schedule, sodium intake, sex, and age, is of interest not only to heuristic but also to practical approaches in clinical medicine
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