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Prostaglandin E biosynthesis and its effect on water permeability were investigated in the toad urinary bladder. Arginine vasopressin (1 mU/ml) increased prostaglandin E (PGE) biosynthesis from 0.5+/-0.1 to 5.0+/-0.4 pmol/min per hemibladder (mean +/-SEM, n= 8, P less than 0.001). Maximal vasopressin-stimulated PGE biosynthesis, 6.4+/-0.2 pmol/min per hemibladder, occurred at vasopressin concentrations in excess of 3 mU/ml. Half-maximal stimulation of PGE biosynthesis occurred at a vasopressin concentration of approximately 0.7 mU/ml, whereas half-maximal stimulation of water flow occurred at a vasopressin concentration of approximately 5 mU/ml. Vasopressin-stimulated PGE biosynthesis did not depend on water flow along an osmotic gradient or upon sodium transport. Thin-layer chromatographic analysis of the lipids released from hemibladders labeled with tritium-arachidonic acid revealed that vasopressin stimulates the release of arachidonic acid from intracellular lipid stores without affecting the percentage of free arachidonic acid converted to PGE. Neither cyclic AMP nor theophylline stimulated PGE biosynthesis although they mimic arginine vasopressin (AVP) in stimulating water permeability. Biosynthesis of PGE was inhibited by mepacrine, a phospholipase inhibitor, and by agents that inhibit arachidonic acid oxygenase. The inhibition of PGE biosynthesis resulted in augmented vasopressin- and theophylline-stimulated water flow, but had no effect on cyclic AMP-stimulated water flow. We interpret these results to mean that endogenous PGE inhibits basal and vasopressin-stimulated adenylate cyclase activity. In contrast to the effects of AVP on permeability and transport, AVP stimulates PGE biosynthesis by a mechanism that does not depend on an increase in cellular cyclic AMP levels. The water permeability response of the toad urinary bladder to vasopressin is inhibited by PGE synthesized by the bladder in response to vasopressin.
R M Zusman, and
H R Keiser, and
J S Handler
July 1983,
The American journal of physiology,
R M Zusman, and
H R Keiser, and
J S Handler
June 1980,
Life sciences,
R M Zusman, and
H R Keiser, and
J S Handler
January 1988,
The American journal of physiology,
R M Zusman, and
H R Keiser, and
J S Handler
January 1982,
Molecular pharmacology,
R M Zusman, and
H R Keiser, and
J S Handler
August 1980,
Proceedings of the National Academy of Sciences of the United States of America,
R M Zusman, and
H R Keiser, and
J S Handler
January 1981,
The Journal of membrane biology,
R M Zusman, and
H R Keiser, and
J S Handler
March 1983,
The Journal of laboratory and clinical medicine,
R M Zusman, and
H R Keiser, and
J S Handler
April 1971,
Annals of the New York Academy of Sciences,
R M Zusman, and
H R Keiser, and
J S Handler
January 1987,
Pharmacology,
R M Zusman, and
H R Keiser, and
J S Handler
January 1989,
Biology of the cell,
