Regulation of Brain Atrial Natriuretic Peptide and Angiotensin Receptors: Quantitative Autoradiographic Studies

Publisher Summary The quantitative autoradiography determines that specific alterations in brain ANG II and ANP receptors occur when blood pressure or fluid consumption are modified and at least some of these central alterations are directly or indirectly related to changes in the peripheral peptide systems. The results indicate a role for the central ANG II and ANP systems in fluid and cardiovascular control and suggest that peripheral and central peptidergic systems are associated, perhaps through peptidergic receptors located outside the blood-brain barrier in contact with the general circulation. The circumventricular organs are connected to some other brain areas that belong to the endogenous brain ANG II and ANP systems. The ANG II and ANP receptor distributions overlap in many areas related to cardiovascular and fluid regulation as well as to the central control of sympathetic activity and pituitary function. Changes in peripheral peptide systems influence the brain directly through their circumventricular organ receptors and influence the central peptide systems as well. Brain receptor numbers can be modulated by alterations in peripheral peptide metabolism. The alterations in brain ANG II receptors during stress provide the first concrete evidence for a role of the peptide in the central control of the pituitary-adrenal axis.