Glomeruli were isolated from rat kidneys using a passive sieving technique to study the mechanisms of basal and beta-adrenergic stimulated renin release. Glomeruli were enclosed within glass chambers and continuously superfused with Krebs media, or modified Krebs as described below, at a rate of 0.3 ml/min. The chamber effluent was collected in 10-minute fractions and measured for renin concent...