A Comparison of the Inhibition of Stromal Adenosinetriphosphatase and Inhibition of Sugar Permeability in Erythrocytes

✍ Scribed by Laris, Philip C. ;Ewers, Arthur ;Novinger, Gordon

• Publisher: Wiley (John Wiley & Sons)
• Year: 1962
• Tongue: English
• Weight: 581 KB
• Volume: 59
• Category: Article
• ISSN: 0095-9898
• DOI: 10.1002/jcp.1030590207

✦ Synopsis

An inhibition of rabbit stromal adenosine triphosphatase activity by phloretin, phloridzin and glucose was reported by Laris, Novinger and Calaprice ('60). Because of a possible relationship to sugar permeability this initial study prompted a more extensive study of inhibition by these compounds. Since sugar permeability varies markedly in mammalian erythrocytes (Laris, '58; Wilbrandt, ' 3 8 ) , a comparison of the action of these inhibitors was made using the stromata of erythrocytes obtained from three different mammals. The three sources of enzymes studied were human, a very permeable cell; rabbit, a slowly but measurably permeable cell; and beef, an apparently impermeable cell in which only glucose metabolism is measurable.

Preparation of stromata. Blood was obtained by veni-puncture from humans, by heart puncture from rabbits, and by exsanguination from beef. The samples were defibrinated with glass beads and washed three times with approximately 10 times their volume of 0.9% sodium chloride solution. The buffy coat and top layers of red cells were discarded. The hematocrits of the samples were adjusted to approximately 40%. The erythrocytes were lysed by alternate freezing and thawing 4 times with dry ice acetone bath and a water bath at 37°C. To insure rapid freezing and thawing 3 ml samples were placed 250 ml erlenmeyer flasks. The hemolysate was centrifuged for 30 minutes at 8,000 rpm at 4°C in a Serval refrigerated centrifuge after addition of 15 times its volume of cold 0.9% NaCl. The stromata were washed 4 times in this manner and the final volume adjusted to