title: Isolation of plasma membranes from rat lungs: effect of age on the subcellular distribution of adenylate cyclase activity.
abstract: A simple and rapid method of isolating plasma membranes from rat lungs is described. The method involves homogenization of tissue in isotonic sucrose-buffered medium followed by differential and sucrose density gradient centrifugation. Plasma membranes obtained by this procedure were essentially free from other subcellular contamination. Plasma membranes isolated from 2-day-old rat lungs showed 6 to 7-fold purification of adenylate cyclase and 5'-nucleotidase activities compared to the original homogenate. In contrast, plasma membranes from 35-day-old rat lungs showed no purification of adenylate cyclase activity although 5'-nucleotidase activity showed similar enrichment. These results suggest that adenylate cyclase activity is not a reliable marker for plasma membranes from adult rat lungs.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D000375:Aging; D000818:Animals; D002451:Cell Compartmentation; D002462:Cell Membrane / Q000201:enzymology*; D002499:Centrifugation, Density Gradient; D008168:Lung / Q000201:enzymology*; D009708:Nucleotidases / Q000378:metabolism; D051381:Rats
chemical_list: D009708:Nucleotidases; D000262:Adenylyl Cyclases