2-Mercaptopropionylglycine and related compounds in treatment of mitochondrial dysfunction and postischemic myocardial damage.

Reversal of mitochondrial dysfunction caused by uncouplers of oxidative phosphorylation, diamide, ageing and ischemia was studied using 2-mercaptopropionylglycine (MPG) in reduced and oxidized (ox-MPG) forms and other SH compounds. Rat heart mitochondria and mitochondrial ATPase, OS-ATPase from beef heart and the isolated working rat heart preparation were examined. MPG and ox-MPG partly prevented and reversed mitochondrial uncoupling and improved deteriorated heart function. ATPase activities were decreased by MPG and ox-MPG in both types of preparation. Three mechanisms are probably involved in thiol action. These comprise alternatively and/or additively: a) SH/S-S interchange reactions; b) free radical scavenger function; c) polar-polar (apolar) interactions. This may contribute to improve oxidative phosphorylation which is considered as a result of recoupling damaged mitochondria by MPG.