ABSTRACT
Angiotensin II (AII) is a peptide of eight amino acids formed by an enzymatic cascade in which the substrate, angiotensinogen, is cleaved by the enzyme renin to form the decapeptide, angiotensin I. The ovarian hormones also affect the activity of other brain peptides, like AII, neuropeptide Y, neurotensin, corticotropin releasing hormone, and oxytocin, which have been demonstrated to influence luteinizing hormone release. All the proteins necessary for the synthesis of AII have been measured in the rat brain. Ovarian hormones have effects upon the components, as well as on the function, of the brain AII system. Brain AII has long been known to participate in the control of a number of physiological functions, including blood pressure regulation, fluid and electrolyte balance, neuronal activity and secretion of hormones from the pituitary gland. The central action of AII to influence prolactin release appears to be inhibitory in nature.
