AMPHIBIAN INTESTINAL BRUSH-BORDER MEMBRANES .1. ISOLATION FROM RANA-CATESBEIANA TADPOLE

Intestinal brush border membrane vesicles were isolated from R. catesbeiana tadpole. EM of brush border membrane vesicles demonstrates a fairly homogenous preparation of vesicles, some of them still containing electron dense material. The dense vesicles probably comprise both microvillus core and membrane. Negative staining of vesicles reveals the presence of knob-like structures (particles) covering the outer surface of the membrane. The membranous fraction is characterized by a high specific activity of alkaline phosphatase, trehalase, glucoamylase, maltase and .gamma.-glutamyltranspeptidase.