Study on Decreased Expression of Calponin Protein in Cultured Cerebral Vascular Smooth-muscle Cells After Exposed to Oxyhemoglobin

Objective:To evaluate the effect of decreased expression of calponin protein in cerebral vascular smooth muscle cells during vasospasm after subarachnoid hemorrhage.Methods:smooth muscle cells were cultured from rabbit basilar artery media,then oxyhemoglobin was added to the medium,and the experimental vasospasm in cultured smooth muscle cells was estabalished.The time course of the expression of contraction inhibiting protein calponin was determined by immunoblotting techniques.Results:After the exposure to oxyhemoglobin,the immunoreactivity for calponin in smooth musle cells decreased to 84.4%±3.1%( P 0.01)on the first day,74.3%±4.3%( P 0.01) on the 4th day,and 54.5%±6.1%( P 0.01) on the 7th day.Conclusion:Oxyhemoglobin impairs expression of contration inhibiting protein in cerebral vascular smooth muscle cells.Expression of contraction protein decreases.These changes contribute to the sustained contraction in smooth muscle.