Mechanism Of Action Proposed For Ribi's MPL-C

Ribi ImmunoChem's new immunomodulator, MPL-C, significantly reduces cardiac infarct size when given prior to a myocardial infarction, according to preclinical animal data presented at the American Heart Association meeting in Anaheim, USA.

In three animal models, preventive use of MPL-C reduced cardiac infarct size by more than 50% when compared to controls. Data has indicated that the agent may influence the adenosine triphosphate-sensitive potassium (KATP) channel. Activation of this channel is believed to be important in preconditioning myocardial tissue against ischemia - opening of KATP channels is associated with efflux of potassium from the cell, preservation of cellular ATP and prevention of intracellular calcium overload, which if not prevented can adversely affect the contractility and viability of heart tissue.

To support this proposed mechanism, a KATP blocker was co-administered to some animals, and the MPL-C cardioprotective effect was eliminated.