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Inhibition by PGE₂ of glucagon-induced increase in phosphoenolpyruvate carboxykinase mRNA and acceleration of mRNA degradation in cultured rat hepatocytes

In cultured rat hepatocytes the key gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PCK) is known to be induced by glucagon via an elevation of cAMP. Prostaglandin E₂ has been shown to antagonize the glucagon-activated cAMP formation, glycogen phosphorylase activity and glucose output in hepatocytes. It was the purpose of the current investigation to study the potential of PGE₂ to inhibit the glucagon-induced expression of PCK on the level of mRNA and enzyme activity. PCK mRNA and enzyme activity were increased by 0.1 nM glucagon to a maximum after 2 h and 4 h, respectively. This increase was completely inhibited if 10 μM PGE2 was added concomitantly with glucagon. This inhibition by PGE₂ of glucagon-induced PCK activity was abolished by pertussis toxin treatment. When added at the maximum of PCK mRNA at 2 h, PGE₂ accelerated the decay of mRNA and reduced enzyme activity. This effect was not reversed by pertussis toxin treatment. Since in liver PGE₂ is derived from Kupffer cells, which play a key role in the local inflammatory response, the present data imply that during inflammation PGE₂ may reduce the hepatic gluconeogenic capacity via a Gᵢ-linked signal chain.

Identiferoai:union.ndltd.org:Potsdam/oai:kobv.de-opus-ubp:4579
Date January 1994
CreatorsPüschel, Gerhard, Christ, Bruno
PublisherUniversität Potsdam, Mathematisch-Naturwissenschaftliche Fakultät. Institut für Ernährungswissenschaft
Source SetsPotsdam University
LanguageEnglish
Detected LanguageEnglish
TypePostprint
Formatapplication/pdf
SourceFEBS Letters 351 (1994), 3, p. 353-356, DOI 10.1016/0014-5793(94)00877-9, ISSN 0014-5793
Rightshttp://opus.kobv.de/ubp/doku/urheberrecht.php

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