QUANTITATIVE MEASUREMENT OF ANGIOTENSIN II (A II) RECEPTORS IN DISCRETE REGIONS OF RAT BRAIN, PITUITARY AND ADRENAL GLANDY BY AUTORATOGRAPHY.

Abstract

All cornponents of the angiotensin (AII) system are present in the central nervoüs system .(l ). AII receptors have.been characterized in nembrane fracti0ns of maíll'ral ian brain (2). Binding sites for drugs and neurotransrnilters ca! be local ized ancl quantítated in brain by autoradiography using [3¡¡¡11"ott,,u and computerized densitometry after in vitrg^lncubat.lon with appropriale ligands (3,4). T'he AII agonist 1251-¡5¿¡ll-AII js a suitable l igand for AII recept0r sturlies since it shows complete cr0ss displacsrient iljth All (5). These receptors have been recently localized in discrete rat brain nuclei (6). Precise quantitation, however, is essential for studies on the pllysiological re- 9ul atj on of receptors. l.,le report tne quantitative deterlllination of AII rece¡Jtors jn. .ar qrain, piLLitd.J ¿no acrenal glan,.: afler incubdLion vvitn -t¿5'l- LSarl]-Al l. Tnis riernod jnvolves Llle use oi Jll-sensirive f il¡r fur for auloradiography (4), selection of appropriate filn exp0sure times, quantitation of optical densities bJ corlputerized microdensitornetry (3) and cornparÍson to lzbl-stdnddrds iJrepared froln i:rain ti ssue (7).