Localization of mRNAs encoding Ca2+-inhibitable adenylyl cyclases along the renal tubule. Functional consequences for regulation of the cAMP content

• Published in: The Journal of biological chemistry Vol. 271; no. 32; pp. 19264 - 19271
• Main Authors: Chabardès, D, Firsov, D, Aarab, L, Clabecq, A, Bellanger, A C, Siaume-Perez, S, Elalouf, J M
• Format: Journal Article
• Language: English
• Published: United States 09.08.1996
• Subjects: Adenylyl Cyclase Inhibitors; Adenylyl Cyclases - genetics; Animals; Arginine Vasopressin - pharmacology; Base Sequence; Calcium - pharmacology; Cyclic AMP - metabolism; DNA Primers; Glucagon - pharmacology; Kidney Medulla - drug effects; Kidney Medulla - metabolism; Kidney Tubules, Collecting - drug effects; Kidney Tubules, Collecting - metabolism; Male; Molecular Sequence Data; Polymerase Chain Reaction; Rats; Rats, Sprague-Dawley; RNA, Messenger - genetics; RNA, Messenger - metabolism
• ISSN: 0021-9258
• DOI: 10.1074/jbc.271.32.19264

Expression of Ca2+-inhibitable types V and VI adenylyl cyclases was studied by reverse transcription-polymerase chain reaction in rat renal glomeruli and nephron segments isolated by microdissection. Quantitation of each mRNA was achieved using a mutant cRNA which differed from the wild type by substituting two bases to create a new restriction site in the corresponding cDNA. Type VI mRNA was present all along the nephron but was more abundant in distal than in proximal segments. The expression of type V mRNA was restricted to the glomerulus and to the initial portions of the collecting duct. Expression of the Ca2+-insensitive type IV mRNA studied on the same samples was evidenced only in the glomerulus. The functional relevance of the expression of Ca2+-inhibitable isoforms was studied by measuring cAMP content in the microdissected outer medullary collecting duct which expressed both type V mRNA (2367 +/- 178 molecules/mm tubular length; n = 8) and type VI mRNA (5658 +/- 543 molecules/mm, n = 8). Agents known to increase intracellular Ca2+ in this segment induced a Ca2+-dependent inhibition on either arginine vasopressin- or glucagon-stimulated cAMP level. The characteristics of these inhibitions suggest a functional and differential expression of types V and VI adenylyl cyclases in two different cell types of the rat outer medullary collecting duct.