Comparative Analysis of Infarct-Limiting Activity of Peptide and Non-Peptide [delta]- and [kappa]-Opioid Receptor Agonists during Heart Reperfusion In Vivo

A comparative analysis of the infarct-limiting activity of [delta]- and [kappa]-opioid receptors (OR) agonists was carried out on a model of coronary occlusion (45 min) and reperfusion (120 min) in male Wistar rats. We used selective [[delta].sub.2]-OR agonist deltorphin II (0.12 mg/kg), [delta]-OR agonists BW373U86 and p-Cl-Phe DPDPE (0.1 and 1 mg/kg), selective agonists of 81-OR DPDPE (0.1 and 0.969 mg/kg), [[kappa].sub.1]-OR U-50,488 (0.1 and 1 mg/kg), [[kappa].sub.2]-OR GR-89696 (0.1 mg/kg), and [kappa]-OR ICI-199,441 (0.1 mg/kg). All drugs were administered intravenously 5 min before reperfusion. Deltorphin II, BW373U86 (1 mg/kg), p-Cl-Phe DPDPE (1 mg/kg), U-50,488 (1 mg/kg), and ICI-199,441 had a cardioprotective effect. The most promising compounds for drug development are ICI-199,441 and deltorphin II. Key Words: heart; ischemia/reperfusion; opioid receptors