Lack of desensitization against α‐agonists and vasopressin in the liver

FEBS Letters

Kleineke, Jochen¹  Söling, Hans-Dieter¹ 

[1] Abteilung für Klinische Biochemie, Zentrum für Innere Medizin der Universität Göttingen, Humboldtallee 1, D-3400 Göttingen, FRG

关键词: Lack of desensitization;    Calcium;    α-Agonists;    Vasopressin;    Hepatocyte (Perfused rat liver);   

DOI  :  10.1016/0014-5793(83)80142-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A heterologous and homologous desensitization of the glycogenolytic response against 3′,5′-cAMP independent hormones in isolated hepatocytes has been reported [Biochem. J. (1981) 200, 509–514]. We re-examined this phenomenon in isolated perfused rat livers, isolated hepatocytes during stationary incubation and in isolated perifused hepatocytes. The release of glucose and the activation of glycogen phosphorylase were followed in the presence of phenylephrine (10⁻⁵ M) or vasopressin (2.5 × 10⁻⁸ M). A desensitization against these hormones could not be observed in the presence of exogenous calcium (1.3 mM). When calcium-free media were applied, the perfused liver became successively resistant toward the action of phenylephrine (or vasopressin), but regained sensitivity immediately after addition of 1.3 mM calcium to the medium. It is concluded that in isolated hepatocytes desensitization against hormones acting via mobilization of intracellular calcium is an artifact resulting from the experimental conditions.

【 授权许可】

Unknown