Primary Study On Effect Of Static Mechanical Stimulation On Regulation Of Mechanical Gated BK_Ca Channels

Large-conductance calcium-activated potassium channels (BKCa ) are present in various tissues of animals. BKCa channels participate in regulations of multiple cellular functions. And more evidence proved that abnormal expression and dysfunction of BKCa channels are closely related to the cardiovascular diseases.In this study, expression vector of alpha subunit of BKCa channel( pTargeT-BKCa-α) was constructed and was transfected into CHO. The transfected CHO were treated under static mechanical stimulation. In addition, chick cardiac myocytes were treated under the same stimulation. Primary effect of BKCa channels treated by static mechanical stimulation in CHO and in chick cardiac myocytes was detected by immunological method and by patch clamp technique separately. The results showed:1. Expression of BKCa channels in CHO transfected by pTargeT-BKCa-αimproved significantly after the mechanical stimulation (Value of strain is 12%) for 12 hours.2. Opening probability of BKCa channels in chick cardiac myocytes increased significantly after the mechanical stimulation (Value of strain is 12%) for 12 hours.The above results showed that increasing of expression and opening probability of BKCa channels resulted from static mechanical stimulation could be used to improve the ability of reducing tension of the whole cell under durative mechanical stimulation.In addition, several expression vectors carrying vrious mutant forms ofαsubunits of BKCa channels have been constructed to provide necessary experimental materials for further study on the regulation mechanisim of mechanical gated BKCa channels.