Intracellular Ca2+ signaling pathway is involved in light-induced phase advance, but may not be in phase delay, of the circadian melatonin rhythm in chick pineal cell

Citation
K. Nakahara et al., Intracellular Ca2+ signaling pathway is involved in light-induced phase advance, but may not be in phase delay, of the circadian melatonin rhythm in chick pineal cell, J PINEAL R, 30(4), 2001, pp. 234-242
Citations number
34
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physiology
Journal title
JOURNAL OF PINEAL RESEARCH
ISSN journal
0742-3098 → ACNP
Volume
30
Issue
4
Year of publication
2001
Pages
234 - 242
Database
ISI
SICI code
0742-3098(200105)30:4<234:ICSPII>2.0.ZU;2-9
Abstract
Chick pineal cells have photoreceptive. circadian clock and melatonin synth etic capacities, and express circadian oscillation of melatonin release in vitro. Light pulses cause phase-dependent phase shift of the melatonin rhyt hm. The purpose of this study was to address the questions whether intracel lular calcium is involved in both light-induced phase advance and delay. Th apsigargin and cyclopiazonic acid, which deplete the intracellular calcium stores, blocked the light-induced phase advance in a dose-dependent manner. The pulses of ryanodine receptor antagonist (dantrolene sodium or rutheniu m red) also blocked the light-induced phase advance. Most agents did not ca use a significant phase shift by themselves. On the other hand, all the age nts used, failed to block the light-induced phase delay, even if the magnit ude of phase delay was decreased using low intensity light. An antagonist o f nitric oxide synthase blocked neither light-induced phase advance nor pha se delay. These results indicate the following possibilities: Il)the mechan ism of light-induced phase advance and delay may be different in chick pine al cells, or (2) if intracellular calcium is involved in both light-induced phase advance and delay, the sensitivity to light and/or agents used in th is study may differ according to Zeitgeber time.