Scutellarin induced Ca(2+ ) release and blocked KCl-induced Ca(2+ ) influx in smooth muscle cells isolated from rat thoracic artery.
This study was designed to investigate the effect of scutellarin (1) on the modulation of intracellular Ca(2+ ) concentration in thoracic smooth muscle cells of rat. Single smooth muscle cells were obtained enzymatically. Fluo-3 AM was used to determine the alteration of intracellular-free Ca(2+ )([Ca(2+ )](i)) and the changes in fluorescence intensity under different agonists were recorded. Compound 1 induced Ca(2+ ) transients in the medium with and/or without Ca(2+ ). In the Ca(2+ )-free medium, after pretreatment of 1, thapsigargin failed to cause the elevation of [Ca(2+ )](i). However, 1 still caused the elevation of [Ca(2+ )](i) after pretreatment of thapsigargin. The infusion of 1 blocked KCl-induced Ca(2+ ) entry and this effect was hardly reversible. The results of present study suggested that 1 increased [Ca(2+ )](i) by blocking sarcoplasmic reticulum Ca(2+ )/ATPase and blocked voltage-dependent Ca(2+ ) channels in smooth muscle cells of the rat thoracic aortic artery.
Zhu
Bang-Hao
BH
Department of Pharmacology, Sun Yat-Sen Medical School, Sun Yat-Sen University, Guangzhou, China. zhubh@mail.sysu.edu.cn
Ma
Li
L
Pan
Xue-Diao
XD
Huang
Yu-Ling
YL
Liu
Jie
J
D000818:Animals; D047310:Apigenin / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D020746:Calcium Channels, L-Type / Q000187:drug effects*; D002478:Cells, Cultured; D004365:Drugs, Chinese Herbal / Q000494:pharmacology; D049919:Erigeron; D005965:Glucuronates / Q000494:pharmacology*; D008297:Male; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000378:metabolism; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000037:antagonists & inhibitors*; D013895:Thoracic Arteries / Q000166:cytology
D020746:Calcium Channels, L-Type; D004365:Drugs, Chinese Herbal; D005965:Glucuronates; C484876:scutellarin; D011189:Potassium Chloride; D047310:Apigenin; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D002118:Calcium