Coronary vasoconstriction in vitro in the hearts of polyarthritic rats: effectiveness of in vivo treatment with the endothelin receptor antagonist SB 209670

Here we demonstrate that perfused hearts removed from polyarthritic rats develop a pronounced coronary vasoconstriction ex vivo. This vasoconstriction is almost entirely blocked by in vivo pretreatment of the rats with the endothelin receptor antagonist, SB 209670. Thus, inflammatory states may be associated with an increased activity of the endothelin system, leading to vascular dysfunction and vasoconstriction.