Alterations of Ca(v)1.2 and 5-hydroxytryptamine in rat hearts after positional asphyxia.

We investigated alterations of cardiac Ca(v)1.2 and 5-hydroxytryptamine (5-HT) associated with positional asphyxia. Male rats were divided into five groups: a control group with no restraint, group 1 restrained for 1 h, group 2 restrained for 2 h, group 3 restrained for 4 h, and group 4 restrained for 8 h. The rats that were restrained for 8 h ultimately suffered fatal asphyxia. After the restraint periods, the rats were sacrificed and immunohistochemistry was performed to evaluate the expressions of Ca(v)1.2 and 5-HT in the heart. Sections were analyzed by digital image analysis. Cardiac expression of Ca(v)1.2 and 5-HT proteins were significantly decreased by positional asphyxia in the rat, shown by integrated optical density (IOD) compared to controls. Our findings indicate that Ca(v)1.2 and 5-HT alterations could cause abnormal cardiac function, and the proteins investigated here may be useful for investigating the mechanisms underlying positional asphyxia.