Effects of changes in hydrostatic pressure on Na transport in gammarid amphipods from Lake Baikal

Abstract

A 60-140-atm change in the hydrostatic pressure causes freshwater gammarid amphipods from Lake Baikal to lose Na+ to the medium. This effect occurs whether the change is an increase in pressure for shallow species or a decrease in pressure for deep species. The pressure effect is predominantly upon unidirectional influx. A pressure-induced change in the dynamic fluidity of the membrane is suggested as a possible mode of action.