Involvement of periodic deacylation-acylation cycles of mitochondrial phospholipids during Sr2+-induced oscillatory ion transport in rat liver mitochondria

Lysophosphatidylcholine and lysophosphatidylethanolamine levels were determined during Sr²⁺-induced oscillating ion fluxes in mitochondria prelabelled in vivo with ³²P_i. Periodic fluctuations of both lyso compounds were established with an increase at the stage of simultaneously monitored K⁺ influx and a decrease at K⁺ efflux. The periodic activations and inactivations of phospholipase were found to be associated with periodic changes in the incorporation rates of labelled polyunsaturated fatty acids with an apparent phase difference of 180°. Periodic deacylation-acylation cycles of phospholipids accompanying the periodic cycles of reversible ion accumulation and release are suggested to be involved in the trigger mechanism generating the permeability changes during oscillatory ion transport.