[Kidney in chronic arterial hypertension: "resetting" and the role of the renal medulla in its development].
In the system of long-term maintenance of the arterial pressure level by means of the renal excretion mechanism described by Guyton et al., the renal medulla with its counterflow-concentrating multiplier and powerful source of natural natriuretics, the prostaglandins, plays the role of a "control device", a regulator setting the level of arterial pressure required for fulfilling the complete volume of renal excretion of salts and water. Increase in systemic arterial pressure causes the development of a complex of structural-functional changes in the kidney, the common purpose of which consists in preventing the loss of salts and water by the organism by shifting parameters of the excretory renal function in such a manner that the normal (balanced with the supply of salts and water to the organism) volume of excretion may occur with higher values (kidney "resetting"). The central role in accomplishing this "resetting" is played by the medullary excretory mechanism which is closely connected, due to the absence of autoregulated blood flow in the medulla, with systemic arterial pressure. When the kidney reaches the "resetting" this mechanism provides for a sufficiently full volume of excretion only when the arterial pressure increases, maintaining its fixed (higher) level by means of the feedback mechanism. In hypertension caused by overdosage of corticosteroid hormones or excess of salt in the diet the increase of pressure develops as a compensation for the occurring deficiency of the medullary excretory mechanism.
D000804:Angiotensin II / Q000097:blood; D000818:Animals; D001160:Arterioles; D001794:Blood Pressure; D002908:Chronic Disease; D004231:Diuresis; D006706:Homeostasis; D006801:Humans; D006973:Hypertension / Q000209:etiology* / Q000503:physiopathology; D006984:Hypertrophy / Q000503:physiopathology; D007668:Kidney / Q000098:blood supply / Q000503:physiopathology*; D007679:Kidney Medulla / Q000503:physiopathology*; D007684:Kidney Tubules / Q000503:physiopathology; D009318:Natriuresis; D009400:Nephrosclerosis / Q000209:etiology; D012083:Renin / Q000097:blood; D014655:Vascular Resistance
D000804:Angiotensin II; D012083:Renin
Pochka pri khronicheskoĭ arterial'noĭ gipertenzii: "perekliuchenie" i rol' pochechnoĭ medully v ego razvitii.