Abstract
The human insulin receptor exists in two isoforms, HIR-A and HIR-B. We studied whether both insulin receptor isotypes are able to mediate an insulin signal to phospholipase C. Plasma membranes were prepared from rat-1 fibroblasts transfected either with HIR-A or HIR-B and insulin stimulated PIP-hydrolysis was determined. We found that insulin stimulates PIP-hydrolysis in a similar dose dependent manner and to a similar extent in plasma membranes expressing HIR-A and HIR-B. These data suggest that both receptor isoforms are equally able to activate phospholipase-C.
MeSH terms
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Adenosine Triphosphate / pharmacology
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Animals
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Calcium / pharmacology
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Cell Membrane / enzymology
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Fibroblasts / enzymology
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Humans
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Insulin / pharmacology*
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Manganese / pharmacology
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Phosphatidylinositol Phosphates*
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Phosphatidylinositols / metabolism
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Rats
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Receptor, Insulin / genetics
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Receptor, Insulin / physiology*
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Transfection
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Type C Phospholipases / metabolism*
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Vanadates / pharmacology
Substances
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Insulin
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Phosphatidylinositol Phosphates
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Phosphatidylinositols
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phosphatidylinositol 4-phosphate
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Vanadates
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Manganese
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Adenosine Triphosphate
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Receptor, Insulin
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Type C Phospholipases
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Calcium