Dotsyuk L. The role of glomerulotubular balance in the regulation circadian rhythm of kidney function in normal and experimental nephritis

Dissertation is the study of nature and mechanisms of regulation of circadian rhythm of kidneys function, role of glomerulotubular balance and tubuloglomerular feedback in a normal and experimental nephrites. In the light phase of a day's cycle it is most likely due to the increased level of serotonin in a kidney parenchima and decline synthesis of nitric oxide likely primary, in the epithelium of macula densa is a process of decrease of speed of glomerular filtration, develops of reabsorption of natrium in the tubular section of nephron increases. This happens in a middle of light phase by the considerable decline of natrium concentration in the area of macula densa. In the dark phase of day's cycle the nitric oxide neutralized influence of serotonin on a. afferens. Proximal reabsorption of natrium rises, as it happened in a light phase, but reabsorption of natrium in a distal tubule went down sharply. Such influence of serotonin and nitric oxide on the functional state of nephron in the dark phase of day's cycle resulted in the substantial increase of natrium concentration in the area of macula densa and considerable natriuresis. The data allow us to draw a conclusion that serotonin, dopamine and nitric oxide function as regulators of both biorhythmic activity of neurons of SCN and circadian activity of peripheral intrarenal pacemaker. During blockade of a central pacemaker serotonin, dopamin and nitric oxide in the kidney preserve adaptive glomerulotubular and tubuloglomerular mutual interaction. This allows kidney to support a circadian rhythm both under control and experimental nephrite.