OKADAIC ACID AND CALYCULIN-A ENHANCE THE EFFECT OF THYROTROPIN-RELEASING-HORMONE ON GH(3) RAT ANTERIOR-PITUITARY-CELLS EXCITABILITY

被引：15

作者：

DELGADO, LM ^{[1
]}

DELAPENA, P ^{[1
]}

DELCAMINO, D ^{[1
]}

BARROS, F ^{[1
]}

机构：

[1] UNIV OVIEDO, FAC MED, AREA BIOQUIM, DEPT BIOL FUNC, E-33006 OVIEDO, SPAIN

来源：

FEBS LETTERS | 1992年 / 311卷 / 01期

关键词：

THYROTROPIN-RELEASING HORMONE; OKADAIC ACID; CALYCULIN-A; PROTEIN PHOSPHATASE; ANTERIOR PITUITARY; PERFORATED PATCH;

D O I：

10.1016/0014-5793(92)81362-P

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Thyrotropin-releasing hormone (TRH) causes a transient hyperpolarization followed by several minutes of increased action potential frequency in patch-perforated current-clamped GH3 cells. Treatment of cells for 5 min with either 2 or 100 nM of the protein phosphatase inhibitor okadaic acid does not affect electrical activity of the cells, but potentiates the enhancement of action potential frequency elicited by a subsequent addition of TRH. Alternatively, 100 nM (but not 2 nM) of okadaic acid added during the second phase of TRH action, further increases the frequency of firing above that produced by the hormone. Similar effects to those of 2 nM okadaic acid are observed with 20 nM calyculin A. These data suggest that a protein phosphatase plays a major role in regulating the delayed effects of TRH on cell excitability in GH3 cells.

引用

页码：41 / 45

页数：5

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