Effetto della cocliobolina sul trasporto attivo del sodio nella pelle isolata di Rana esculenta

Abstract

INFLUENCE OF COCHLIOBOLIN ON ACTIVE TRANSFER OF SODIUM ACROSS THE ISOLATED FROG SKIN. — Previous papers reported the hypothesis that the first site of attack of cochliobolin on plant materials is probably the cell membrane. Indeed, an impairement of cell permeability, possibly disrupting the processes and the structures which regulate the active adsorption, appears as the common origin of all the phenomena observed. A study of the effects of cochliobolin on net active transfer of sodium across the isolated frog skin might therefore help to elucidate the mechanism of action of the toxin. Esperiments carried on with this aim, showed that over a range of cochliobolin concentration from 30 to 0,2 μg/ml, the net transfer of sodium is markedly promoted during the first 60–90 minutes. Moreover, with intermediate concentrations, a first increase of sodium transfer is followed by a second larger one. These informations cannot yet be readily rationalized; however they offer further evidence that an interference with active adsorption, presumably acting on the cell membrane activity, must be regarded as the first locus of cochliobolin mechanism of action.