The inositol phosphate/diacylglycerol pathway in MA-10 Leydig tumor cells. Activation by arginine vasopressin and lack of effect of epidermal growth factor and human choriogonadotropin.
It is now well established that mouse epidermal growth factor (mEGF) modulates the hormonal responsiveness of MA-10 Leydig tumor cells but does not affect cell multiplication. The studies presented herein are the first in a series of experiments designed to characterize the intracellular signaling systems activated by mEGF and their possible roles in mediating the diverse biological actions of this growth factor in MA-10 cells. We show that (i) MA-10 cells express a hormone-sensitive inositol phosphate/diacylglycerol pathway that can be stimulated with arginine vasopressin (AVP), (ii) mEGF does not activate this pathway, and (iii) activation of this pathway with arginine vasopressin does not mimic the biological actions of mEGF. Other data presented show that lutropin/choriogonadotropin, the principal endocrine regulators of Leydig cell function, also do not stimulate the inositol phosphate/diacylglycerol pathway in MA-10 cells.
Ascoli
M
M
Population Council, New York, New York 10021.
Pignataro
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OP
Segaloff
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D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology*; D006063:Chorionic Gonadotropin / Q000378:metabolism / Q000494:pharmacology*; D004075:Diglycerides / Q000502:physiology*; D004789:Enzyme Activation / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005989:Glycerides / Q000502:physiology*; D007295:Inositol Phosphates / Q000502:physiology*; D007984:Leydig Cell Tumor / Q000378:metabolism*; D051379:Mice; D010716:Phosphatidylinositols / Q000378:metabolism; D011974:Receptors, LH / Q000378:metabolism; D013403:Sugar Phosphates / Q000502:physiology*; D014407:Tumor Cells, Cultured; D010738:Type C Phospholipases / Q000378:metabolism
D006063:Chorionic Gonadotropin; D004075:Diglycerides; D005989:Glycerides; D007295:Inositol Phosphates; D010716:Phosphatidylinositols; D011974:Receptors, LH; D013403:Sugar Phosphates; D001127:Arginine Vasopressin; D004815:Epidermal Growth Factor; D010738:Type C Phospholipases