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Titolo:
SPONTANEOUS AND AGONIST-INDUCED CALCIUM OSCILLATIONS IN SINGLE HUMAN NONFUNCTIONING ADENOMA CELLS
Autore:
VACHER P; BRESSONBEPOLDIN L; DUFYBARBE L; ODESSA MF; GUERIN J; DUFY B;
Indirizzi:
UNIV BORDEAUX 2,CNRS URA 1200,NEUROPHYSIOL LAB,BP 22,146 RUE LEO SAIGNAT F-33076 BORDEAUX FRANCE CHR,DEPT NEUROCHIRURG BORDEAUX FRANCE
Titolo Testata:
Endocrine
fascicolo: 2, volume: 4, anno: 1996,
pagine: 123 - 132
SICI:
1355-008X(1996)4:2<123:SAACOI>2.0.ZU;2-O
Fonte:
ISI
Lingua:
ENG
Soggetto:
GONADOTROPIN-RELEASING-HORMONE; HUMAN PITUITARY-TUMORS; PROTEIN-KINASE-C; LUTEINIZING-HORMONE; RAT GONADOTROPES; CENTRIFUGAL ELUTRIATION; ADENYLYL CYCLASE; GNRH RECEPTOR; PHORBOL ESTER; K+ CURRENT;
Keywords:
MICROSPECTROFLUOROMETRY; GONADOTROPIN-RELEASING HORMONE; GONADOTROPIN-RELEASING HORMONE-ASSOCIATED PEPTIDE; PKCS; IP3; DIHYDROPYRIDINES; THAPSIGARGIN; CA2+ INFLUX; INTRACELLULAR CA2+ STORES;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
45
Recensione:
Indirizzi per estratti:
Citazione:
P. Vacher et al., "SPONTANEOUS AND AGONIST-INDUCED CALCIUM OSCILLATIONS IN SINGLE HUMAN NONFUNCTIONING ADENOMA CELLS", Endocrine, 4(2), 1996, pp. 123-132

Abstract

The effects of gonadotropin-releasing hormone (GnRH) and GnRH-associated peptide (GAP) on cytosolic free calcium concentration ([Ca2+](i)) were investigated in 20 human nonfunctioning pituitary adenomas. We divided these tumors into three classes according to their response pattern to hypothalamic peptides. In type I adenomas (8 out of 20 adenomas), GnRH and GAP mobilized intracellular calcium ions stored in a thapsigargin (TG)-sensitive store. For the same concentration of agonist, two distinct patterns of GnRH-, GAP-induced Ca2+ mobilization were observed (1) sinusoidal oscillations, and (2) monophasic transient, The latter is followed by a protein kinase C (PKC)-dependent increase in calcium influx through L-type channels. In type II adenomas (7 out of 20 adenomas), GnRH and CAP only stimulate calcium influx through dihydropyridine-sensitive Ca2+ channels by a PKC-dependent mechanism. TG (1 muM) did not affect [Ca2+](i) in these cells, suggesting that they do not possess TG-sensitive Ca2+ pools. All the effects of GnRH and CAP were blocked by an inhibitor of phospholipase C (PLC), suggesting that they were owing to the activation of the phosphoinositide turnover, Type I and type II adenoma cells showed spontaneous Ca2+ oscillations that were blocked by dihydropyuidines and inhibition of PKC activity. GnRH and GAP had no effect on the [Ca2+](i) of type I II adenoma eel Is that were also characterized by a low resting [Ca2+](i) and by the absence of spontaneous Ca2+ fluctuations. K+-induced depolarization provoked a reduced Ca2+ influx, whereas TG had no effect on the [Ca2+](i) oftype III adenoma cells. The variety of [Ca2+](i) response patterns makes these cells a good cell model for studying calcium homeostasis in pituitary cells.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 12/07/20 alle ore 06:52:03