The adrenal cortex and the kidney

The adrenal cortex regulates renal function in a number of important ways; indeed, normal renal function cannot be understood without recognition of such regulation. Well-recognized examples of such regulation are the control of body fluid tonicity through regulation of urinary solute concentration-a function controlled “primarily” by vasopressin, but secondarily and importantly by the adrenal cortex-and control of body sodium-a function controlled primarily by renal tubular sodium reabsorption but regulated by sodium-retaining steroids.The kidney can regulate adrenal function by changing reabsorption of sodium and secretion of potassium, and also by release of renin. The primary target of such regulation is the secretion of aldosterone, which may be influenced by body fluid volume, potassium ion and angiotensin II.Because of these interrelationships, the pathophysiology of certain disease states may be described as aberrations in feedback loops between adrenal cortex and kidney. In this paper we will consider this “system” in some detail, and attempt to explain four disorders as examples of errors in control.In the form of “primary” aldosteronism resulting from hyperplasia of all adrenal cortical tissue, overproduction of aldosterone persists in the absence of all known stimulatory factors. In renovascular hypertension, angiotensin and aldosterone production may persist despite systemic hypertension. In the non-salt-losing form of the adrenogenital syndrome of congenital adrenal hyperplasia without treatment, failure of feedback inhibition by Cortisol may result in overproduction of adrenocorticotropic hormone (ACTH) which, in turn, may lead to overproduction of progesterone. Progesterone may cause sodium loss and overproduction of renin and aldosterone while blocking their effects. In the syndrome of juxtaglomerular hyperplasia with normal blood pressure, overproduction of renin may result from unresponsiveness of blood vessels leading to a lack of feedback inhibition by pressure rise. Under certain circumstances sodium loss can potentiate both the overproduction and the unresponsiveness. Excessive renin leads to aldosteronism and potassium loss

Nanomaterials by severe plastic deformation: review of historical developments and recent advances

International audienceSevere plastic deformation (SPD) is effective in producing bulk ultrafine-grained and nanostructured materials with large densities of lattice defects. This field, also known as NanoSPD, experienced a significant progress within the past two decades. Beside classic SPD methods such as high-pressure torsion, equal-channel angular pressing, accumulative roll-bonding, twist extrusion, and multi-directional forging, various continuous techniques were introduced to produce upscaled samples. Moreover, numerous alloys, glasses, semiconductors, ceramics, polymers, and their composites were processed. The SPD methods were used to synthesize new materials or to stabilize metastable phases with advanced mechanical and functional properties. High strength combined with high ductility, low/room-temperature superplasticity, creep resistance, hydrogen storage, photocatalytic hydrogen production, photocatalytic CO2 conversion, superconductivity, thermoelectric performance, radiation resistance, corrosion resistance, and biocompatibility are some highlighted properties of SPD-processed materials. This article reviews recent advances in the NanoSPD field and provides a brief history regarding its progress from the ancient times to modernity

Clinical, Epidemiological and Chronobiological Studies on the Relationship between Blood Pressure and Mineral Intake

The clinical, epidemiological and chronobiological studies on the relationship between blood pressure and salt, potassium or magnesium intake have been investigated over the past thirty years. These studies can be divided into six categories as follows : 1) Abnormalities of electrolytes metabolism : primary aldosteronism and Bartter\u27s syndrome. 2) Clinical studies on salt sensitivity in patients with idiopathic hypertension. 3) Chronobiological studies of blood pressure (BP) and urinary electrolyte excretion related to BP regulation, including the Fukuoka-Minnesota collaborative chronoepidemiological study, as well as studies on the circadian rhythms of urinary electrolytes during total parenteral nutrition, studies on the reapportionment of salt intake and circadian blood pressure patterns, and so on. 4) An estimation of the 24-h urinary sodium and potassium excretion from spot-urine specimens. 5) Comparative epidemiological studies on the genesis of hypertension in Nepal. 6) The effects of high-potassium, high magnesium or high fiber intake on blood pressure and the metabolism of lipids and carbo-hydrates in humans. An increasing number of elderly people are expected to suffer from either mild or borderline hypertension in the future. Thus, life-style modification (non-pharmacological treatment), most notably the appropriate intake of such minerals as sodium, potassium, magnesium and calcium, are now considered to be increasingly more important for the treatment of this hypertensive condition

Antihypertensive Mechanism of Food for Specified Health Use : \u22Eucommia leaf glycoside\u22 and its clinical application

Eucommia is a native Chinese medical herb. The cortex of eucommia has long been used as an antihypertensive medicine. \u22Eucommia leaf glycoside\u22 is a substance extracted from the leaf. A cooling drink has been prepared from the extracts and named \u27Tochu 120\u27. Eucommia leaf glycoside was listed as a food for specified health use in 1997. Its antihypertensive mechanism is thought to involve an agonistic effect on the parasympathetic system based on results of several animal experiments. A double- blind placebo-controlled clinical study of 103 subjects with either high normal blood pressure (BP) or mild hypertension was conducted by means of both casual BP measurement and 24-hour ambulatory BP monitoring. A long-term clinical study was also performed for two years. In these studies, \u27Tochu 120\u27 was found to have mild antihypertensive effects and neither side effects nor adverse effects was observed in either clinical study. These results suggest that \u27Tochu 120\u27, a food for specified health use, is useful for non-pharmacological treatment of mildly hypertensive subjects including those who have high normal BP