Alkali secretion in the turtle bladder: up-regulation by the phospho-inositol cascade and inhibition by diphenylamine carboxylate (DPC).
The presently reported studies of factors involved in the regulation of acid-base excretory processes in isolated turtle urinary bladders have yielded the following data. (i) There exists in alkalotic and euhydric turtle bladders (but not in acidotic turtle bladders) a mechanism which drives a primary active electrogenic secretion of alkali; and the electrogenic output of this mechanism is up-regulated by exogenously added PDE inhibitors, such as theophylline or IBMX. (ii) VIP or cAMP up-regulates this alkali secretion in the presence of IBMX. (iii) Carbachol also initiates alkali secretion. But this action, independent of PDE activity, is probably associated with the phospho-inositol reaction cascade. (iv) Finally, low concentrations of mucosal DPC decreases the carbachol supported, but not the cAMP-supported alkali secretion.
Schneider
E S
ES
Mount Sinai School of Medicine, Dept. Physiol.-Biophys., N.Y., N.Y. 10029.
Durham
J H
JH
Matons
C
C
Brodsky
W A
WA
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000037:antagonists & inhibitors; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D002794:Choline / Q000502:physiology; D000242:Cyclic AMP / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D010716:Phosphatidylinositols / Q000378:metabolism*; D013806:Theophylline / Q000494:pharmacology; D014426:Turtles / Q000502:physiology*; D001743:Urinary Bladder / Q000187:drug effects / Q000378:metabolism*; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology; D062367:ortho-Aminobenzoates / Q000494:pharmacology*
D010716:Phosphatidylinositols; D062367:ortho-Aminobenzoates; D014660:Vasoactive Intestinal Peptide; D002217:Carbachol; C001209:fenamic acid; D013806:Theophylline; D000242:Cyclic AMP; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D002794:Choline; D015056:1-Methyl-3-isobutylxanthine