Inhibition of L-type calcium currents by magnesium sulfate on the rat basilar artery smooth muscle cells
- Author:
Naveen Sharma
;
Janardhan Prasad Bhattarai
;
Pyoung Han Hwang
;
Seong Kyu Han
;
Yun Su Yang
- Publication Type:Journal Article
- From:Neurology Asia
2014;19(3):301-307
- CountryMalaysia
- Language:English
-
Abstract:
Objective: Vasospasm remains the leading cause of cerebral damage after aneurysmal subarachnoid
hemorrhage. Although magnesium regulates the calcium influx in vascular smooth muscle and
endothelial cells, it has not been reported whether L-type calcium channels are involved in magnesiuminduced
vascular relaxation in rat basilar artery. So, the effect of magnesium sulfate on L-type calcium
currents in freshly isolated smooth muscle cells from rat basilar artery was investigated. Methods:
The smooth muscle cells were isolated from rabbit basilar artery by enzyme treatment. L-type Ca2+
currents were identified using cesium chloride, a potassium channel blocker and Bay K8644, an
activator of L-type Ca2+ channel. Currents were recorded under step pulse whole cell patch clamp
technique. Results: In the presence of cesium chloride (in pipette solution), inward currents were
observed by depolarizing step pulses. The inward currents were significantly reduced by nimodipine
(n=4, p<0.05), an L-type Ca2+ channel blocker and increased by Bay K8644 (n=5, p<0.05), an L-type
Ca2+ channel activator. The L-type calcium currents (156±17.0 pA, n=12) were significantly reduced
by the application of 5 mM magnesium sulfate (53.8±7.0 pA, n=12, p<0.01).
Conclusion: These results suggest that magnesium may relax cerebral vessel of rat basilar artery
through decreasing intracellular Ca2+ ion by inhibition of L-type Ca2+ channels.
- Full text:P020150630493009457175.pdf
