Stimulation of septation in mitochondria by diamide, a thiol oxidising agent.

Diamide (10-(4)M), a thiol oxidizing agent, rapidly promotes septation in isolated frog liver mitochondria an also in situ in liver slices. The effect is partially inhibited by dithioerythritol. DNP does not have this effect, and it is concluded that diamide does not promote septation via an uncoupling action. The septate mitochondria have a different appearance from typical dividing mitochondria previously described; it is suggested that (1) diamide may act by favouring the fusion of the internal membranes, and (2) -SH oxidation is of importance in mitochondria in ageing and in various pathological conditions. The ways in which septa may develop in mitochondria in the orthodox and condensed configuration are discussed.