کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1931932 | 1050569 | 2010 | 6 صفحه PDF | دانلود رایگان |
The β subunits of voltage-dependent calcium channels are known to modify calcium channel currents through pore-forming α1 subunits. The β3 subunit is expressed in the adrenal gland and participates in forming various calcium channel types. We performed a series of experiments in β3-null mice to determine the role of the β3 subunit in catecholamine release from the adrenal chromaffin system.Protein levels of N-type channel forming CaV2.2 and L-type forming CaV1.2 decreased. The β3-null mice showed a decreased baroreflex, suggesting decreased sympathetic tonus, whereas plasma catecholamine levels did not change. Pulse-voltage stimulation revealed significantly increased amperometrical currents in β3-null mice, while patch–clamp recordings showed a significant reduction in Ca2+-currents due to reduced L- and N-type currents, indicating facilitated exocytosis. A biochemical analysis revealed increased InsP3 production.In conclusion, our results indicate the importance of the β3 subunit in determining calcium channel characteristics and catecholamine release in adrenal chromaffin cells.
Journal: Biochemical and Biophysical Research Communications - Volume 394, Issue 3, 9 April 2010, Pages 464–469