Alterations in Angiotensin and Atrial Natriuretic Peptide Receptors in Brain Nuclei of Spontaneously Hypertensive Rats

Abstract

We stud¡ed angiotensin ll (ANG ll) and atrial natriuretic peptide (ANP) receptors in brain areas of young (4-week-old) and adult (14-week-old) spontaneously hypertensive rats (SHR) and their age-matched normotensive controls, Wistar-Kyoto rats (WKY), after incubation of brain sections with 12sl-l¡gands and quantitative autorad¡ography. The number of ANP binding sites was decreased in the subfornical organ (SFO) and the area postrema of young and adult SHR and in the nucleus of the solitary tract (NTS) of adult SHR. Conversely, the number of ANG ll binding s¡tes was high in the SFO of young and adult hypertensive animals and in the NTS of young SHR. Our results indicate a central role for ANP and ANG ll in genetic hypertension and suggest that these pept¡des may act as mutual antagonists in brain areas related to the conüol of blood pressure and fluid regulation.