Atrial natriuretic factor receptors in rat kidney, adrenal gland, and brain: Autoradiographic localization and fluid balance dependent changes

Mammalian atria contain natriuretic peptides designated atrial natriuretic factors (ANF). Using in vitro autoradiography with ¹²⁵I-labeled ANF, we have localized high-affinity (K(d) = 150 pM) ANF binding sites to the glomeruli of the kidney, zona glomerulosa of the adrenal gland, and choroid plexus of the brain. The numbers of sites in both kidney and adrenal are increased in rats deprived of water; increases are detectable within 72 hr of water deprivation in the kidney and within 24 hr in the adrenal gland. Receptor numbers decline in rats given 2.0% NaCl as drinking water and in diabetic rats. The discrete localizations and dynamic alterations of these receptors suggest that ANF regulates fluid balance through diverse but coordinated effects on receptors in numerous organs including the kidney, adrenal, and brain.