Amiloride enhances atrial natriuretic factor stimulation of cGMP accumulation in rat glomeruli

The effects of amiloride on ANF binding and ANF stimulation of cGMP were evaluated in rat glomeruli. Amiloride increased ANF binding to whole glomeruli and to glomerular membrane preparations. In contrast, amiloride enhanced ANF-stimulated cGMP accumulation only at 37 degrees C in whole glomeruli, but not at 4 degrees C in whole glomeruli or at 37 degrees C in membrane preparations. These data suggest that under physiological conditions amiloride augments ANF-stimulated intracellular cGMP accumulation. The discrepancies between amiloride augmentation of ANF binding and failure to increase ANF-stimulated cGMP accumulation may result from ANF receptor heterogeneity. This is the first report of an amiloride augmentation of ANF-stimulated cGMP accumulation in renal tissue.