Under normal physiological conditions, self-regulation occurs, and special circumstances will only be neurologically regulated (blood is redistributed to areas that need it more).
Renal blood flow depends on blood pressure/resistance.
The renal arterial pressure can regulate blood flow and stabilize GFR between 80-160mmHg. Outside this range, blood flow increases when blood pressure is elevated.
Myogenic mechanism: When blood pressure increases, blood vessels dilate, pulling on the endothelial calcium channels, causing calcium influx and smooth muscle contraction.
- Vasoconstriction during excitement
Sympathetic nervous system stimulation causes vasoconstriction and decreased blood flow;
Epinephrine, norepinephrine, AngⅡ, vasopressin
- Vasodilation during relaxation
Prostaglandins, acetylcholine, atrial natriuretic peptide
During periods of rest within the normal range of blood pressure fluctuations, self-regulation is primarily relied upon to maintain relatively stable blood flow and normal urinary function.
In cases of significant bleeding and other situations, neurohumoral regulation causes renal vasoconstriction, redistribution of systemic blood flow, and allocation of blood to vital organs such as the brain and heart.