Involvement of protein kinase C in the regulation of cortisol production by guinea pig adrenocortical cells.
Cytosol of the guinea pig adrenals was found to contain a protein kinase which was dependent on the presence of both calcium and phospholipids (phosphatidylserine and diolein), i.e., calcium/phospholipid-dependent protein kinase (protein kinase C). The peak of protein kinase C was separated from type II cAMP-dependent protein kinase by DE-52 chromatography. 12-0-Tetradecanoylphorbol-13-acetate (TPA) caused dose-dependent increments of cortisol formation without affecting cAMP formation by guinea pig adrenocortical cells as well as angiotensin II did. TPA-activated cortisol production was blocked by the addition of aminoglutethimide and cycloheximide, suggesting that the site of action of TPA might be located at a point before the production of pregnenolone in the mitochondria. Since TPA showed an increase in the cortisol production, protein kinase C may be involved in modulating steroidogenesis in the guinea pig adrenals in addition to the classical cAMP-dependent protein kinase pathway.
Department of Internal Medicine (II), School of Medicine, Chiba University, Japan.
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Nishikawa
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Yoshida
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Y
Tamura
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Yoshida
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000302:Adrenal Cortex / Q000166:cytology / Q000378:metabolism*; D000616:Aminoglutethimide / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D003513:Cycloheximide / Q000494:pharmacology; D006168:Guinea Pigs; D006854:Hydrocortisone / Q000096:biosynthesis*; D066298:In Vitro Techniques; D008297:Male; D011493:Protein Kinase C / Q000502:physiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D000616:Aminoglutethimide; D000804:Angiotensin II; D003513:Cycloheximide; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D015056:1-Methyl-3-isobutylxanthine; D006854:Hydrocortisone