Influence of Exogenous Prostaglandin E2 and Stress on Circulating Corticosterone Concentrations in Coturnix

The effects of exogenous prostaglandin E2 (PGE2) injections and stress on circulating corticosterone (B) levels in Coturnix were determined. Adult Japanese quail (Coturnix coturnix japonica) were subjected to one of four treatments: 1) injected with vehicle; 2) injected with PGE2; 3) immobilized for 10 min, followed by vehicle injection; or, 4) immobilized for 10 min, followed by PGE2 injection. Injections were given intraperitoneally, and blood samples were collected by cardiac stab at 15-min postinjection treatment. Plasma B concentrations were quantified by radioimmunoassay. Immobilized, vehicle injected quail had higher plasma B levels than unstressed, vehicle-injected quail. Plasma B levels were significantly greater in unstressed, PGE2-injected quail than in unstressed, vehicle injected quail or in stressed, vehicle injected quail. The effects of immobilization stress and PGE2 injection on B secretion were additive; stressed PGE2-injected quail had significantly higher plasma B levels than unstressed, PGE2-injected quail. It is concluded that, as in mammals, PGE2 is a potent stimulator of adrenal B release in quail.