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E Tria

Publications and source records attributed to E Tria.

At least 19 recordsLinked to original sources

Insulin effect in vitro on human erythrocyte plasma membrane.

The effect of porcine insulin has been tested in vitro on human erythrocyte plasma membrane (Na+-K+) and Mg2+-ATPase activities as well as on membrane fluidity. The results indicate that the hormonal treatment significantly inhibits (Na+-K+)-ATPase activity, and at the same time decreases membrane fluidity.

Adenosine Triphosphatases

Effect of chlorpropamide and phenformin on rat liver: the effect on plasma membrane-bound enzymes and cyclic AMP content of hepatocytes in vitro.

Chlorpropamide and phenformin inhibited (Na+ - K+)-ATPase and stimulated a high affinity cyclic AMP-phosphodiesterase of isolated liver plasma membrane when tested in vitro. In addition, the two drugs decreased the intracellular cyclic AMP content of isolated hepatocytes without being effective on plasma membrane-bound adenylate cyclase. The results suggest that the plasma membrane plays an important role in the mechanism of action of the two hypoglycemic drugs, but do not exclude the presence of intracellular targets.

3',5'-Cyclic-AMP Phosphodiesterases

Insulin-sensitive adenosine 3',5'-cyclic monophosphate phosphodiesterase of hepatocyte plasma membrane.

Adenosine 3',5'-cyclic monophosphate phosphodiesterase (EC 3.1.4.17) has been investigated in rat liver as to its insulin sensitivity. Hormone action has been assayed in vitro on a liver homogenate purified by DEAE-cellulose column chromatography, on isolated hepatocytes, on isolated plasma membranes. The DEAE-cellulose chromatography purified homogenate showed no sensitivity to insulin, whereas isolated hepatocytes incubated in presence of insulin showed increased phosphodiesterase activity in a plasma membrane-containing fraction. The plasma membrane-bound enzyme, which shows both high and low affinity components, was significantly stimulated after hormonal treatment; this effect being dependent on a V increase of the low Km form.

3',5'-Cyclic-AMP Phosphodiesterases