Angiotensin II

Angiotensin II acts at the Na/H exchanger in the proximal tubules of the kidney to stimulate Na reabsorption and H excretion which is coupled to bicarbonate reabsorption. This ultimately results in an increase in blood volume, pressure, and pH. Hence, ACE inhibitors are major anti-hypertensive drugs.

Angiotensin is a peptide hormone that induces vasoconstriction and an increase in blood pressure. It is part of the renin-angiotensin system, which regulates blood pressure. Angiotensin stimulates the release of aldosterone from the adrenal cortex to promote sodium retention by the kidneys. Angiotensin II acts on the CNS to increase vasopressin production, and also acts on venous and arterial smooth muscle to cause vasoconstriction. Angiotensin II also increases aldosterone secretion, therefore, it acts as an endocrine, autocrine/paracrine, and intracrine hormone.