(45) THE LINEAR EVENTS OF THE PERMEABILITY TRANSITION PORE OPENING

B.F. Krasnikov (1,2), A.E. Kuzminova (1)*, Yu.A. Antonenko (1) and D.B. Zorov (1)
(1) A.N.Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119899 Russia
(2) International Laser Center, Moscow State University, Moscow, 119899 Russia.

It is known that the permeability transition pore opening in mitochondria is featured by changes in their functional and structural state. These changes include oxygen uptake reflecting respiratory activity of mitochondria, membrane potential indicating the energy state of a system, ion fluxes showing the ionic homeostasis, and volume reflecting osmotic equilibrium. Many of investigators observe these events and suggest that the process of high amplitude swelling of mitochondrial is the final event of the mitochondria permeability transition. Four parameters were recorded simultaneously from mitochondria in a specially designed setup. After computer analysis of the data, we determined the sequence of events during pore opening that was induced by calcium ions and prevented by cyclosporine A. First, calcium transporting systems are activated. This event is closely followed by depolarization of the mitochondrial membrane and activation of electron flow through the respiratory chain. High amplitude swelling of mitochondria is the final event of this phenomena.

Supported by grants RFBR #96-04-49384, #98-04-48641, #98-04-48383, University of Russia #5102 and Volkswagen Stiftung.

*AEK was responsible for a majority of the work to be presented by BFK.