Effect of BRL-37344 on ion channel in guinea pig cardiac myocytes / 第三军医大学学报

ABSTRACT

Objective To study the biological effect of ?3 adrenoceptor-activated electrophysiological activities in cardiac myocytes. Methods Changes of transient outward potassium ( Ito) and L-type calcium current ( ICa-L) in primary cultured guinea pig cardiacmyocytes were detected with the standard whole-cell patch clamp technique about 5 -10 min before and after administration of ?3 adrenoceptor agonist,4--2-hydroxy-( 3-chlorophenyl) ethyl-aminopropylphenoxyacetate ( BRL-37344; BRL). Results BRL could significantly increased the Ito in guinea pig cardiac myocytes with the I-V curve up-moved. When the membrane potential reached to + 80 mV,the density current increased from 6. 11 ? 1. 03 pA/pF to 8. 46 ? 2. 07 pA/pF ( n = 6,P =0. 013 064). BRL ( 10 -6mol/L) could significantly increase the ICa-Lin guinea pig cardiac myocytes,which was ( 2. 30 ?0. 75) -fold higher than in control group( n =5,P =0. 0063). When the membrane potential increased to + 10 mV ,the current,increased from 89. 25 ? 17. 83 pA to 205. 00 ? 72. 24 pA ( n = 5,P = 0. 006 3). Conclusion BRL-37344 can increase the transient Itoand ICa-L,thus further regulating the cardiac activities.