|
|
||||||||
AJP - Cell Physiology, Vol 254, Issue 1 C115-C121, Copyright © 1988 by American Physiological Society
ARTICLES |
S. M. O'Grady, H. R. DeJonge, A. B. Vaandrager and M. Field
Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York 10032.
We explored the potential role of cyclic nucleotide-dependent protein phosphorylation in regulating ion transport across flounder intestinal mucosa by studying the effects of N-[2(methylamino)-ethyl]-s-isoquinolinesulfonamide (H-8), a selective inhibitor of cyclic nucleotide-dependent protein kinase in vitro. Addition of H-8 reversed the inhibitory effects of 8-bromoguanosine 3',5'-cyclic-monophosphate (8-BrcGMP), 8-bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP), atriopeptin III (AP III), and vasoactive intestinal peptide (VIP) on the short-circuit current (Isc) and transepithelial potential difference (PD). Flux measurements established that these changes in Isc and PD directly reflected changes in Na and Cl absorption by the intestine. H-8 was unable, however, to reverse the inhibitory effects on Isc and PD of the Ca ionophore ionomycin and of substance P at dosages exceeding those needed to reverse the effects of AP III, VIP, and the cyclic nucleotides. We conclude that 1) H-8 (100 microM or less) does not exert toxic effects, 2) exogenously added cyclic nucleotide analogues inhibit ion transport through activation of cyclic nucleotide-dependent kinases resulting in protein phosphorylation, 3) activation of these kinases is an essential intermediate step in the inhibitory action of AP III and VIP on ion transport, and 4) the Ca ionophore ionomycin and substance P appear to inhibit ion transport by a mechanism that is independent of cyclic nucleotide-dependent protein phosphorylation.
This article has been cited by other articles:
![]() |
R. M. Pelis and J. L. Renfro Active sulfate secretion by the intestine of winter flounder is through exchange for luminal chloride Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2003; 284(2): R380 - R388. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. S. Marshall, J. A. Howard, R. R. F. Cozzi, and E. M. Lynch NaCl and fluid secretion by the intestine of the teleost Fundulus heteroclitus: involvement of CFTR J. Exp. Biol., March 15, 2002; 205(6): 745 - 758. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Lytle Activation of the Avian Erythrocyte Na-K-Cl Cotransport Protein by Cell Shrinkage, cAMP, Fluoride, and Calyculin-A Involves Phosphorylation at Common Sites J. Biol. Chem., June 13, 1997; 272(24): 15069 - 15077. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |