Epidermal growth factor stimulates release of arachidonic acid in pig epidermis.
Epidermal growth factor (EGF) at physiologic concentrations (0.001-0.1 microgram/ml) stimulated the release of [14C] arachidonic acid [14C-AA] from pig epidermis. Although EGF stimulated the release of AA in the absence of exogenously added calcium to some extent, the addition of calcium (0.3-1.2 mM) significantly potentiated the release of AA stimulated by EGF. Ionophore A23187, which is known to stimulate phospholipase A2 activity by opening the calcium gates, potentiated the EGF-stimulated release of AA. The stimulatory effect of EGF was partially inhibited by the addition of mepacrine (70% inhibition at 10 microM) and by the pretreatment of hydrocortisone (60% inhibition at 1.0 microM). The loss of 14C-labeled phospholipids in pig epidermis was mainly due to the degradation of 14C-labeled phosphatidylcholine. Present results and recent reports by other workers suggest that EGF stimulates phospholipase A2 activity and result in the increased release of AA.
D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism*; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000502:physiology; D004815:Epidermal Growth Factor / Q000276:immunology / Q000502:physiology*; D004817:Epidermis / Q000378:metabolism*; D006854:Hydrocortisone / Q000494:pharmacology; D007106:Immune Sera / Q000494:pharmacology; D066298:In Vitro Techniques; D010741:Phospholipases A / Q000037:antagonists & inhibitors / Q000378:metabolism; D054467:Phospholipases A2; D011796:Quinacrine / Q000494:pharmacology; D013552:Swine
D001095:Arachidonic Acids; D007106:Immune Sera; D000001:Calcimycin; D004815:Epidermal Growth Factor; D010741:Phospholipases A; D054467:Phospholipases A2; D011796:Quinacrine; D002118:Calcium; D006854:Hydrocortisone