[Effects of oxidized LDL, hypoxia, and 5-hydroxytryptamine on 5-HT2A receptor and intracellular free Ca2+ in cultured vascular smooth muscle cells].
OBJECTIVE
To investigate the mechanisms of this hyperreactivity, the effects of oxLDL, hypoxia, and 5-HT (the relative factors inducing arteriosclerosis) on 5-HT2A receptor, receptor gene expression and intracellular free Ca2+ were observed in cultured rat aortic smooth muscle cells (ASMC).


METHODS
ASMC underwent 50 micrograms/ml oxLDL 8 hours, 2% hypoxia 24 and 48 hours, 10 mumol/L 5-HT 30 min. 5-HT2A receptor, 5-HT2A receptor mRNA and [Ca2+]i of ASMC were estimated by radiobinding assay, RT-PCR and Southern blot method, and confocal laser scanning mode separately.


RESULTS
After oxLDL, hypoxia, 5-HT pretreatment, 5-HT2A receptor of ASMC showed significant up-regulation. Both 5-HT2A receptor mRNA expression and 5-HT-induced [Ca2+]i of ASMC increased markedly after oxLDL, hypoxia pretreatment.


CONCLUSIONS
5-HT2A receptor up-regulation and cell [Ca2+]i increase of ASMC induced by oxLDL, hypoxia, and 5-HT may play a role in vascular hyperreactivity induced by 5-HT in atherosclerosis arteries.
Pang
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Y
Department of Pathophysiology, Institute of Basic Medical Sciences, CAMS, PUMC, Beijing 100005, China.
Xu
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S
Xue
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Q
D000818:Animals; D001011:Aorta / Q000166:cytology; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D000860:Hypoxia / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D044402:Receptor, Serotonin, 5-HT2A / Q000378:metabolism*; D012701:Serotonin / Q000494:pharmacology*
D008077:Lipoproteins, LDL; D044402:Receptor, Serotonin, 5-HT2A; C099252:oxidized low density lipoprotein; D012701:Serotonin; D002118:Calcium