Effects of DMSO on the Active Sodium Transport Across Frog Skin / 대한피부과학회지

ABSTRACT

As an attempt to evaluate any possible effects of dimethylsulfoxide (DMSO) on the phenomena of membrane transport, effects on the short-circuit current (SCC) and potential difference (PD) across the isolated frog skin were studied under the conditions of various bathing medium, Changes of SCC and PD were measured by the method described by Ussing and Zerahn. Addition of DMSO to the inside bathing medium resulted in an initial increase in SCC followed by a secondary decline to pre-DMSO level, while DMSO at outside medium was without effect. Dose-responses(SCC) relationship revealed a linear one from 30 to 60 mM. Substitution of chloride by sulfate ion from bathing medium caused no alteration in the basic pattern and magnitude of response, thus indicating the specificity of DMSO action on the Na transport. Hypertonic solutions of DMSO added to either outer or inner bathing medium evoked a prompt fall in SCC and PD consistently. By isotopic measurement of sodium fluxes with Na24, it was evident that increased sodium influx was entirely responsible for the initial increase in SCC induced by DMSO. Of various parameters concerned with transepithelial Na transport, outer membrane permeability to Na (PoNa) was shown to be the onIy parameter which was significantly elevated by DMSO administration. From these findings, it was postulated that DMSO-induced increment in sodium influx was mediated by its stimulating action on the sodium penctration through the outer permeability barricr after binding to a receptor site different from that for the antidiuretic hormone (ADH.)