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R Kinne

Publications and source records attributed to R Kinne.

At least 127 records · Page 7Linked to original sources

Target cell polarity and membrane phosphorylation in relation to the mechanism of action of antidiuretic hormone.

The plasma membrane of the bovine renal collecting duct epithelial cell has been resolved into its apical (luminal) and basal-lateral (contraluminal) components by free flow electrophoresis. The contraluminal, but not the luminal, membrane was found to contain antidiuretic hormone-sensitive adenylate cyclase. The luminal membrane was found to contain a cyclic 3':5'-adenosine monophosphate-sensitive self-phosphorylating system consisting of a membrane-bound protein kinase and its membrane-bound substrate(s); this intrinsic protein kinase was not present in the contraluminal membrane. These findings provide direct evidence that the initiating steps in the action of antidiuretic hormone on the kidney take place at the contraluminal pole of the hormonesensitive target cell and that the late or terminal steps occur at the luminal pole, where they involve an alteration in the level of membrane phosphorylation.

Adenosine Triphosphatases↗

Analysis of the pinocytic process in rat kidney. I. Isolation of pinocytic vesicles from rat kidney cortex.

Pinocytosis was induced in rat kidney by exposure to horseradish peroxidase (HRP). Pinocytic vesicle preparations were enriched after homogenization of kidney cortex by differential centrifugation and free-flow electrophoresis with HRP as an exogenous marker. Vesicles were identified by enzymatic analysis and by electron microscopy, including specific staining procedures. Typical brush-border enzymes such as alkaline phosphatase, aminopeptidase, 5'-nucleotidase, lysosomal acid phosphatase, and mitochondrial succinic dehydrogenase were reduced in the vesicular fraction, compared to the kidney cortex homogenate. Glucose-6-phosphatase and Na(+)-K(+)-ATPase were only slightly increased in the fraction. These results indicate that preparations of pinocytic vesicles from rat kidney cortex can be enriched. They have biochemical characteristics that differ from those of the cell organelles and membranes previously purified from renal tissue.

Acid Phosphatase↗

The polarity of the proximal tubule cell in rat kidney. Different surface charges for the brush-border microvilli and plasma membranes from the basal infoldings.

Two different membrane fractions were obtained from a brush-border fraction of rat kidney cortex by using their different electrical surface charges in preparative free-flow electrophoresis. One membrane fraction contained only morphologically intact microvilli and was characterized by a high specific activity of alkaline phosphatase. The other fraction morphologically resembled classical plasma membranes by possessing junctional complexes and a high Na-K-ATPase activity The contamination of the isolated membrane fractions by other cell organelles was extremely low These two fractions represent the apical (luminal) and the basal (interstitial) area of the renal proximal tubule cell membrane and clearly demonstrate the polarity of this cell.

Adenosine Triphosphatases↗