Cellular localization of type 5 and type 6 ACs in collecting duct and regulation of cAMP synthesis

• Published in: American journal of physiology. Renal physiology Vol. 279; no. 1; pp. F185 - F194
• Main Authors: Héliès-Toussaint, C, Aarab, L, Gasc, J M, Verbavatz, J M, Chabardès, D
• Format: Journal Article
• Language: English
• Published: United States 01.07.2000
• Subjects: Adenylyl Cyclase Inhibitors; Adenylyl Cyclases - genetics; Adenylyl Cyclases - metabolism; Animals; Aquaporin 3; Aquaporins - analysis; Blotting, Western; Calcium - metabolism; Carbachol - pharmacology; Cyclic AMP - metabolism; Dinoprostone - pharmacology; Glucagon - pharmacology; In Situ Hybridization; Isoenzymes - genetics; Isoenzymes - metabolism; Kidney Cortex - enzymology; Kidney Cortex - metabolism; Kidney Medulla - enzymology; Kidney Medulla - metabolism; Kidney Tubules, Collecting - cytology; Kidney Tubules, Collecting - drug effects; Kidney Tubules, Collecting - enzymology; Kidney Tubules, Collecting - metabolism; Male; Rats; Rats, Sprague-Dawley; RNA, Messenger - analysis; RNA, Messenger - genetics
• ISSN: 1931-857X; 1522-1466
• DOI: 10.1152/ajprenal.2000.279.1.f185

The cellular distribution of Ca(2+)-inhibitable adenylyl cyclase (AC) type 5 and type 6 mRNAs in rat outer medullary collecting duct (OMCD) was performed by in situ hybridization. Kidney sections were also stained with specific antibodies against either collecting duct intercalated cells or principal cells. The localization of type 5 AC in H(+)-ATPase-, but not aquaporin-3-, positive cells demonstrated that type 5 AC mRNA is expressed only in intercalated cells. In contrast, type 6 AC mRNA was observed in both intercalated and principal cells. In microdissected OMCDs, the simultaneous superfusion of carbachol and PGE(2) elicited an additive increase in the intracellular Ca(2+) concentration, suggesting that the Ca(2+)-dependent regulation of these agents occurs in different cell types. Glucagon-dependent cAMP synthesis was inhibited by both a pertussis toxin-sensitive PGE(2) pathway (63.7 +/- 4.6% inhibition, n = 5) and a Ca(2+)-dependent carbachol pathway (48.6 +/- 3.3%, n = 5). The simultaneous addition of both agents induced a cumulative inhibition of glucagon-dependent cAMP synthesis (78.2 +/- 3.3%, n = 5). The results demonstrate a distinct cellular localization of type 5 and type 6 AC mRNAs in OMCD and the functional expression of these Ca(2+)-inhibitable enzymes in intercalated cells.