A vesicular preparation enriched in basolateral membranes from cow ciliary body epithelium.
A procedure is described for the preparation of a tissue fraction enriched in basal-lateral membranes of the epithelium of ciliary body dissected from abattoir-derived cow eyes. Microscopical methods established the viability of the epithelial cells in the dissected tissue. A two-step homogenization procedure was employed. First, mild trituration with a Potter-Elvehjem tissue grinder was used to release the epithelial cells with minimal disintegration of the stroma and muscle components. Then, complete vesiculation of the released material was induced with a Dounce homogenizer. This material was fractionated through sequential differential and (Ficoll 400) equilibrium density gradient centrifugation steps. The procedure led to the isolation of a fraction enriched 16.8 +/- 5.5 (+/- SE, n = 5) fold in Na(+)+K(+)-ATPase activity with respect to the initial homogenate. Using a method to artificially generate pH gradients it was demonstrated that the preparation contained sealed vesicles and that the membranes of these vesicles exhibited a K+ selectivity consistent with a plasma membrane origin.
DeBacker
C M
CM
Department of Ophthalmology, Mount Sinai School of Medicine, City University of New York, New York 10029.
Wolosin
J M
JM
D000818:Animals; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D002463:Cell Membrane Permeability; D002470:Cell Survival; D002499:Centrifugation, Density Gradient; D005591:Chemical Fractionation / Q000379:methods; D002924:Ciliary Body / Q000166:cytology / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008722:Methods; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
D008565:Membrane Proteins; D000254:Sodium-Potassium-Exchanging ATPase