Study represents mechanism of essential hypertension (EH) origination. Chronic illnesses, sleep disturbance are attributes of essential decrease of kidneys vascular tone, correlated with basal vascular tone of kidneys. Tone decrease is accompanied by activation of action of endocrine vasoconstrictive systems hormones, which stimulates thickening, hypertrophy of vascular smooth muscle cells, prevents vessel stretching, pressure decrease. Increase of physical activity stimulates increase of the reduced kidney basal tone through neurogenic and myogenic stimulations of vessel contractions. Diet improvement also contributes to tone recovery.
Increase of the reduced basal tone is longitudinal contraction of vessels with thick walls, therefore (i) lumen of vessels is reduced, diastolic pressure raises, (ii) tissue oxygenation raises, normalized, the reduced reabsorption rate of Na raises, homeostasis is normalized, (iii) intravascular blood volume is increased, volumes of intercellular space, dilated kidneys and not kidneys vessels are contracted. Normalization of homeostasis is the additional (secondary) stimulus, raising a tone.
Sharp and significant decrease of kidneys tone, causes sharp activation of renin-angiotensin system (RAS) and simpatico-adrenal system (SAS) and stimulates EH with the expressed first stage, with increased pulse rate. Thus, ability of vessels to raise the reduced basal tone is (i) property necessary for maintenance of a normal metabolism, and (ii) reason of EH. The offered mechanism explains the main enigma of EH: vascular resistance is increased without increase of vasoconstrictive substances concentration.