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

共 27 条

[1] CALCIUM CURRENTS IN GH3 CULTURED PITUITARY-CELLS UNDER WHOLE-CELL VOLTAGE-CLAMP - INHIBITION BY VOLTAGE-DEPENDENT POTASSIUM CURRENTS [J].

BARROS, F ;

KATZ, GM ;

KACZOROWSKI, GJ ;

VANDLEN, RL ;

REUBEN, JP .

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1985, 82 (04) :1108-1112

[2] EFFECTS OF HYPOTHALAMIC PEPTIDES ON ELECTRICAL-ACTIVITY AND MEMBRANE CURRENTS OF PATCH PERFORATED CLAMPED GH3 ANTERIOR-PITUITARY-CELLS [J].

BARROS, F ;

DELGADO, LM ;

MACIA, C ;

DELAPENA, P .

FEBS LETTERS, 1991, 279 (01) :33-37

[3]

BARROS F, 1992, IN PRESS PFLUGERS AR

[4] AN INWARD-RECTIFYING K+ CURRENT IN CLONAL RAT PITUITARY-CELLS AND ITS MODULATION BY THYROTROPIN-RELEASING-HORMONE [J].

BAUER, CK ;

MEYERHOF, W ;

SCHWARZ, JR .

JOURNAL OF PHYSIOLOGY-LONDON, 1990, 429 :169-189

[5] INHIBITORY EFFECT OF A MARINE-SPONGE TOXIN, OKADAIC ACID, ON PROTEIN PHOSPHATASES - SPECIFICITY AND KINETICS [J].

BIALOJAN, C ;

TAKAI, A .

BIOCHEMICAL JOURNAL, 1988, 256 (01) :283-290

[6] THE MECHANISMS BY WHICH VASOACTIVE-INTESTINAL-PEPTIDE (VIP) AND THYROTROPIN-RELEASING-HORMONE (TRH) STIMULATE PROLACTIN-RELEASE FROM PITUITARY-CELLS [J].

BJORO, T ;

SAND, O ;

OSTBERG, BC ;

GORDELADZE, JO ;

TORJESEN, P ;

GAUTVIK, KM ;

HAUG, E .

BIOSCIENCE REPORTS, 1990, 10 (02) :189-199

[7] THE STRUCTURE AND REGULATION OF PROTEIN PHOSPHATASES [J].

COHEN, P .

ANNUAL REVIEW OF BIOCHEMISTRY, 1989, 58 :453-508

[8] OKADAIC ACID - A NEW PROBE FOR THE STUDY OF CELLULAR-REGULATION [J].

COHEN, P ;

HOLMES, CFB ;

TSUKITANI, Y .

TRENDS IN BIOCHEMICAL SCIENCES, 1990, 15 (03) :98-102

[9]

COHEN P, 1989, J BIOL CHEM, V264, P21435

[10]

DRUMMOND AH, 1989, INOSITOL LIPIDS CELL, P355

← 1 2 3 →