Osmotically-induced volume changes in isolated cells of a pond snail

1. 1. To assess whether the stretch-activated (SA) channels in snail cells could contribute to osmoregulation, information is needed about the behaviour of the cells under anisosmotic conditions. 2. 2. Cells of Lymnaea stagnalis were therefore examined during acute hyposmotic stress (HOS). 3. 3. Kidney, heart and neuronal cells (monitored photographically) swelled less than expected for strictly semipermeable cells, but exhibited no regulatory volume decrease. 4. 4. Long-term viability of the cells was not compromised following acute hyposmotic stress. 5. 5. Quinidine, which blocks SA channels in Lymnaea, intensified stress-induced swelling most markedly in kidney cells. 6. 6. The data can, however, be explained without invoking recruitment of SA channels.