Role of mitochondria in Ca(2+) oscillations and shape of Ca(2+) signals in pancreatic acinar cells.
Biochem Pharmacol
; 63(2): 283-92, 2002 Jan 15.
Article
em En
| MEDLINE
| ID: mdl-11841804
ABSTRACT
We studied the role of mitochondria in Ca(2+) signals in fura-2 loaded exocrine pancreatic acinar cells. Mitochondrial depolarization in response to carbonylcyanide-p-tryfluoromethoxyphenyl hydrazone or rotenone (assessed by confocal microscopy using rhodamine-123) induced a partial but statistically significant reduction in the decay of Ca(2+) signals under different experimental conditions. Spreading of Ca(2+) waves evoked by the pancreatic secretagogue cholecystokinin cholecystokinin octapeptide was accelerated by mitochondrial inhibitors, whereas the cytosolic Ca(2+) concentration ([Ca(2+)](i)) oscillations in response to physiological levels of this hormone were suppressed by rotenone and carbonylcyanide-p-tryfluoromethoxyphenyl hydrazone. Oligomycin, an inhibitor of mitochondrial ATP synthase, did no affect either propagation of calcium waves nor [Ca(2+)](i) oscillations. Individual mitochondria of rhod-2 loaded acinar cells showed heterogeneous matrix Ca(2+) concentration increases in response to oscillatory and maximal levels of cholecystokinin octapeptide. On the other hand, using Ba(2+) for unequivocal study of capacitative calcium entry we found that mitochondrial inhibitors did not affect this process. Our results show that although the role of mitochondria as a Ca(2+) clearing system in exocrine cells is quantitatively secondary, they play an essential role in the spatial propagation of Ca(2+) waves and in the development of [Ca(2+)](i) oscillations.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pâncreas
/
Cálcio
/
Sinalização do Cálcio
/
Mitocôndrias
Limite:
Animals
Idioma:
En
Revista:
Biochem Pharmacol
Ano de publicação:
2002
Tipo de documento:
Article