PHYSIOLOGICAL EFFECTS OF A PLASMA PROTEIN: BLOOD PRESSURE, LEUCOCYTE CONCENTRATION, SMOOTH AND CARDIAC MUSCLE ACTIVITY

Abstract

A protein concentrate has been obtained from bovine plasma which has profound depressor effect when injected intraven., either in dogs or guinea pigs. The depressor effect is immediate in its onset. Depending upon the quantity administered, animals may or may not survive. This substance is called vascularin. It also produces a leucopenia, which is sudden in onset, but reversible in character. The lymphocytes are relatively less effected than the granulocytes. It stimulates the smooth muscle of the rabbit intestine. In perfusion expts. with the isolated turtle heart, there is a decrease in cardiac output, and these effects on the heart are reversible. Vascularin has the properties of an euglobulin, it is non-dialyzable, it is unusually heat stable for a plasma protein, and it does not lose its physiologic activity when reduced with cysteine or glutathione. Glutathione and cysteine destroy the activity of fibrinolysin.