Atrial natriuretic peptide and its second messenger cGMP inhibited an amiloride-sensitive cation channel in the apical membrane of renal inner medullary collecting duct cells.
Does atrial natriuretic peptide (ANP) inhibit amiloride-sensitive cation channels in renal inner medullary collecting duct cells?
This study provides the first evidence that ANP regulates single ion channels via cGMP, suggesting its natriuretic action involves cGMP-mediated inhibition of electrogenic Na+ absorption in the inner medullary collecting duct.
The patch-clamp technique was used to examine the effects of atrial natriuretic peptide (ANP) and its second messenger guanosine 3′,5′-monophosphate (cGMP) on an amiloride-sensitive cation channel in the apical membrane of renal inner medullary collecting duct cells. Both ANP (10 -11 M ) and dibutyryl guanosine 3′,5′-monophosphate (10 -4 M ) inhibited the channel in cell-attached patches, and cGMP (10 -5 M ) inhibited the channel in inside-out patches. The inner medullary collecting duct is the first tissue in which ANP, via its second messenger cGMP, has been shown to regulate single ion channels. The results suggest that the natriuretic action of ANP is related in part to cGMP-mediated inhibition of electrogenic Na + absorption by the inner medullary collecting duct.
Light et al. (1989) studied Renal inner medullary collecting duct cells. Atrial natriuretic peptide (ANP) and cGMP was evaluated on Inhibition of amiloride-sensitive cation channel. Atrial natriuretic peptide and its second messenger cGMP inhibited an amiloride-sensitive cation channel in the apical membrane of renal inner medullary collecting duct cells.