Membrane Of Frog Skin Research Articles

EFFECT OF OUABAIN ON ACTIVE TRANSPORT OF SODIUM IN THE CORNEA.

<h3>Introduction</h3> Ouabain (G-Strophanthin) inhibits the activity of Na-K activated adenosinetriphosphatase (ATPase) in in vitro and in vivo systems.^1-3The active transport of Na and K across the membranes of frog skin and erythrocytes is also inhibited by ouabain.^4,5Simon and Bonting⁶have shown Na-K activated ATPase to be present in the ciliary body and to be inhibited by ouabain. Administration of ouabain resulted in a decrease in aqueous flow and a drop in intraocular pressure, presumably due to an inhibition of sodium transport across the ciliary epithelium.^6AThe corneal epithelium actively transports sodium,⁷but the enzyme Na-K activated ATPase has not yet been demonstrated in this tissue. It was the purpose of this investigation to study the effect of ouabain on the active transport of sodium across the corneal epithelium. <h3>Method</h3> A technique for maintaining rabbit corneas alive between two Lucite chambers so that the

The effect of low concentrations of thiol-group-blocking agents on the outer membrane of frog skin

The effect of some thiol-group-blocking agents in the solution bathing the outside of isolated frog skin was investigated by a simple method permitting of measuring two separate membrane potentials in the skin and of membrane d.c. resistances to individual ions. It was found that, while higher concentrations of these agents bring about a drop in the membrane potentials and permeability changes, similarly to mercuric chloride, lower concentrations, after a short period of incubation of the skin, cause considerable hyperpolarization of the outer membrane. The hyperpolarization is explained as a result of increased permselectivity of the outer membrane in Ussing's model of frog skin. The conditions of the reaction involved are described and a crude model of the outer membrane is suggested.