Toxicity of fatty acid 18:5n3 from Gymnodinium cf. mikimotoi: II. Intracellular pH and K+ uptake in isolated trout hepatocytes.

ABSTRACT

Effects of octadecapentaenoic acid 185n3 and other related polyunsaturated fatty acids present in gymnodinium cf. mikimotoi were tested in isolated trout hepatocytes. These exotoxins decreased intracellular pH followed by a slow recovery to initial value and alkalinization of acidic compartments, suggesting an inhibition of vacuolar H(+)-ATPases. Moreover, addition of 185n3 to the extracellular medium induced a decrease of K+ uptake into hepatocytes as a result of Na,K-ATPase inhibition. However, high concentrations (10(-5)-10(-3) M) are necessary to induce these effects.