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Titolo:
Patch-clamp-induced perturbations of [Ca2+](i) activity in somatotropes
Autore:
Robert, C; Tseeb, V; Kordon, C; Hammond, C;
Indirizzi:
INSERM, U159, F-75014 Paris, France INSERM Paris France F-75014INSERM, U159, F-75014 Paris, France
Titolo Testata:
NEUROENDOCRINOLOGY
fascicolo: 5, volume: 70, anno: 1999,
pagine: 343 - 352
SICI:
0028-3835(199911)70:5<343:PPO[AI>2.0.ZU;2-4
Fonte:
ISI
Lingua:
ENG
Soggetto:
ANTERIOR-PITUITARY-CELLS; HORMONE-RELEASING-FACTOR; INTRACELLULAR CALCIUM-CONCENTRATION; ACTIVATED ION CHANNELS; INDUCED GH SECRETION; PACEMAKER ACTIVITY; EXTRACELLULAR NA+; CA2+ OSCILLATIONS; EPITHELIAL-CELLS; SMOOTH-MUSCLE;
Keywords:
Ca2+ channels; patch clamp; mechanosensitivity; somatotropes; nifedipin; gadolinium; patch clamp;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
29
Recensione:
Indirizzi per estratti:
Indirizzo: Hammond, C INSERM, U159, 2 Rue Alesia, F-75014 Paris, France INSERM 2 Rue Alesia Paris France F-75014 F-75014 Paris, France
Citazione:
C. Robert et al., "Patch-clamp-induced perturbations of [Ca2+](i) activity in somatotropes", NEUROENDOCR, 70(5), 1999, pp. 343-352

Abstract

Somatotropes and GC cells, a GH-producing cell line, exhibit [Ca2+](i) oscillations that result from rhythmic Ca2+ action potentials. Determination of this operating mode required simultaneous recording of both parameters byfura-2 imaging and patch-clamp techniques. In order to test whether patch recording induces artificial alteration of the [Ca2+](i) oscillatory pattern, we recorded separately or simultaneously [Ca2+](i) and membrane potential. In the absence of any other stimulation, seal formation in patch-clamp recording evoked by itself a 2.5- to 4-fold persistent increase in basal [Ca2+](i), speeded up their frequency (from 0.03-0.17 to 0.4 Hz) and changed their pattern to a tonic mode. Patch-induced [Ca2+](i) increase was reproduced by mechanical contact between the pipette and the membrane. It was reduced by nifedipine, a blocker of L-type Ca2+ channels, as well as by removal of external Na+, It was fully blocked by external Ca2+ removal or gadolinium. All patch-clamp-induced perturbations were reversed by membrane hyperpolarization. We propose that patch-clamp recording evokes Ca2+ entry through L-type Ca2+ channels either directly, or indirectly via membrane depolarization. This shows that patch recordings in endocrine cells showing mechanosensitivity have to be interpreted with caution, and explains why long-lasting patch recordings are so difficult to obtain. Copyright (C) 1999 S. KargerAG, Basel.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 02/04/20 alle ore 19:29:39