Intracellular calcium involvement in pituitary adenylate cyclase-activating polypeptide and gonadotrophin secretion stimulation of growth hormone in goldfish pituitary cells

被引:30
作者
Sawisky, GR [1 ]
Chang, JP [1 ]
机构
[1] Univ Alberta, Dept Biol Sci, Edmonton, AB T6G 2E9, Canada
关键词
intracellular Ca2+ stores; SERCA; mitochondria; PLC;
D O I
10.1111/j.1365-2826.2005.01312.x
中图分类号
R5 [内科学];
学科分类号
1002 ; 100201 ;
摘要
The involvement of intracellular Ca2+ stores and their regulatory mechanisms in mediating pituitary adenylate cyclase-activating polypeptide (PACAP) stimulation of growth hormone (GH) and maturational gonadotrophin (GTH-II) secretion from goldfish pituitary cells was investigated using a cell column perifusion system. Pretreatment with caffeine abolished the GH and GTH-II responses to PACAP. Dantrolene attenuated PACAP-elicited GTH-II release but did not affect the GH response, whereas ryanodine and 8-bromo-cADP ribose did not alter PACAP-induced GH and GTH-II release. Two endoplasmic/sarcoplasmic reticulum Ca2+ ATPase (SERCA) inhibitors, thapsigargin and cyclopiazonic acid, augmented PACAP-induced GTH-II release; similarly, thapsigargin elevated GH responses to PACAP. Treatment with carbonyl cyanide m-chlorophenylhydrazone, a mitochondrial uncoupler, reduced PACAP-stimulated GH release; however, inhibition of the mitochondrial Ca2+ uniport by Ru360 did not affect GH and GTH-II responses. The phosphatidl inositol (PI)-specific phospholipase C (PLC) inhibitor ET-18-OCH3 inhibited, whereas the phosphatidyl-choline (PC)-specific PLC inhibitor D609 enhanced, PACAP-stimulated GH and GTH-II responses. On the other hand, the IP3 receptor blocker xestospongin D had no effect on PACAP-induced GTH-II response and potentiated the GH response. These results suggest that, despite some differences between GH and GTH-II cells, PACAP actions in both cell types generally rely on a caffeine-sensitive, but a largely ryanodine receptor-independent, mechanism. PC-PLC and some SERCA negatively modulate PACAP actions but mitochondrial Ca2+ stores per se are not important. A novel PI-PLC mechanism, which does not involve the traditional IP3/Ca2+ pathway, is also suggested.
引用
收藏
页码:353 / 371
页数:19
相关论文
共 59 条
[1]   Differential calcium responses to the pituitary adenylate cyclase-activating polypeptide (PACAP) in the five main cell types of rat anterior pituitary [J].
Alarcón, P ;
García-Sancho, J .
PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY, 2000, 440 (05) :685-691
[2]   Inhibition of intestinal dipeptide transport by the neuropeptide VIP is an anti-absorptive effect via the VPAC1 receptor in a human enterocyte-like cell line (Caco-2) [J].
Anderson, CMH ;
Mendoza, ME ;
Kennedy, DJ ;
Raldua, D ;
Thwaites, DT .
BRITISH JOURNAL OF PHARMACOLOGY, 2003, 138 (04) :564-573
[3]   Effect of D609 on phosphatidylcholine metabolism in the nuclei of LA-N-1 neuroblastoma cells: a key role for diacylglycerol [J].
Antony, P ;
Farooqui, AA ;
Horrocks, LA ;
Freysz, L .
FEBS LETTERS, 2001, 509 (01) :115-118
[4]  
BLEASDALE JE, 1990, J PHARMACOL EXP THER, V255, P756
[5]   Inverse relationship between membrane lipid fluidity and activity of Na+/H+ exchangers, NHE1 and NHE3, in transfected fibroblasts [J].
Bookstein, C ;
Musch, MW ;
Dudeja, PK ;
McSwine, RL ;
Xie, Y ;
Brasitus, TA ;
Rao, MC ;
Chang, EB .
JOURNAL OF MEMBRANE BIOLOGY, 1997, 160 (03) :183-192
[6]   Move over protein kinase C, you've got company: Alternative cellular effectors of diacylglycerol and phorbol esters [J].
Brose, N ;
Rosenmund, C .
JOURNAL OF CELL SCIENCE, 2002, 115 (23) :4399-4411
[7]   Modulation of [Ca2+]i signaling dynamics and metabolism by perinuclear mitochondria in mouse parotid acinar cells [J].
Bruce, JIE ;
Giovannucci, DR ;
Blinder, G ;
Shuttleworth, TJ ;
Yule, DI .
JOURNAL OF BIOLOGICAL CHEMISTRY, 2004, 279 (13) :12909-12917
[8]   Secretory granule exocytosis [J].
Burgoyne, RD ;
Morgan, A .
PHYSIOLOGICAL REVIEWS, 2003, 83 (02) :581-632
[10]   Role of Ca2+ stores in dopamine- and PACAP-evoked growth hormone release in goldfish [J].
Chang, JP ;
Wong, CJH ;
Davis, PJ ;
Soetaert, B ;
Fedorow, C ;
Sawisky, G .
MOLECULAR AND CELLULAR ENDOCRINOLOGY, 2003, 206 (1-2) :63-74