The platelet-perfused in-vitro heart: an alternative model for studying the role of endogenous prostacyclin and thromboxane in control of coronary perfusion.

A new experimental in-vitro model is described, which was used for studying prostacyclin (PGI2)-thromboxane A2 (TXA2)-interactions. Langendorff hearts of guinea pigs are perfused at constant volume with Krebs-Henseleit buffer and washed human platelets (4 x 10(8)/min). PGI2 and TXA2 release are measured by bioassay. The cardiac and coronary function and the myocardial oxygen consumption are continuously monitored. The platelet count in the cardiac effluent can be measured and the cAMP content has been estimated. This model might be a useful tool for studying the roles of PGI2 and TXA2 in platelet activation and coronary perfusion in terms of endogenously synthesized substances.