[Renin release from microdissected superficial, midcortical, and juxtamedullary afferent arterioles in rabbits]

Though renin release from a single superficial afferent arteriole has been studied extensively, there is no report on renin release from a single midcortical or juxtamedullary afferent arteriole. In the present study, we microdissected the entire afferent arterioles from superficial, middle, and juxtamedullary cortex of rabbit kidney, and examined renin release from a single afferent arteriole. In result, we got the following conclusions. 1. Basal renin release per afferent arteriole decreases steeply from superficial to midcortical to juxtamedullary afferent arterioles during both normal and low sodium intake. 2. Isoproterenol (1.6 x 10(-4)M) significantly stimulates renin release from all three types of arterioles on either diet; however, only in the superficial arterioles is the increase (delta) greater with dietary sodium restriction. These findings indicate substantial heterogeneity of basal and isoproterenol-stimulated renin release, and response to chronic sodium depletion.