ISSN:
1432-1424
Keywords:
Key words: Parotid — Potassium current — Chloride current — Carbachol — Isoproterenol — Calcium
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract. Isoproterenol (IPR) and 8-(4-chlorophenylthio)-cyclic AMP (cpt-cAMP) enhanced carbachol (CCh)-induced fluid secretion from rat parotid glands, but had no effect by themselves. The enhancement by IPR was blocked by propranolol. In dispersed parotid acinar cells, IPR and cpt-cAMP potentiated CCh-induced K+ and Cl− currents (I K and I Cl). IPR at the concentration of 0.1 μm significantly potentiated the CCh-induced increase in intracellular Ca2+ concentration ([Ca2+] i ), but 1 mm cpt-cAMP did not. The incidence of the potentiation by IPR in CCh-induced Mn2+ entry was 31% and that by cpt-cAMP was 21%. The potentiation by IPR in the ionic currents and the [Ca2+] i was suppressed by propranolol. These results suggest that the CCh-induced fluid secretion from rat parotid glands is enhanced by IPR through the potentiation of I K and I Cl mainly by the increased cyclic AMP level and partially by the potentiated Ca2+ influx and [Ca2+] i increase, and that IPR is more effective than cpt-cAMP in the enhancement of the CCh-induced [Ca2+] i increase.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002329900405
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