Aspecific alkaline phosphatase of amphibia integument. Levamisole effect on short-circuit current (SCC).

Using the Ussing chamber technique we have measured the short-circuit current (SCC), and so the ion transport, in the ventral skin of samples of Rana esculenta complex. The animals were not exposed to experimental treatment, and on SCC we have observed the effect of levamisole, administered either on external or internal side. Levamisole 0.0025 mM was ineffective; higher concentrations (0.025 mM, 2.5 mM), which inhibit alPase activity in tissue extracts and sections, induced an increase in SCC measurements and the effect was proportional to the concentration. Levamisole 25 mM produced a rapid and transitory increase of SCC, followed by a very quick decrement of it. Because of the action of Levamisole, "specific inhibitor of alPase activity", on ion transport in Rana skin, we propose that the alPase enzyme is probably involved in ion cutaneous transport and thus in the adaptative osmoregulation in the integument of amphibia