CAJ | 학술논문

目的：探讨衰老对大鼠肠系膜动脉平滑肌细胞大电导钙激活钾通道（BKCa）生物物理特性的影响。方法选用老年组（22～24月龄）和青年组（4～5月龄）雄性Wistar大鼠，采用膜片钳内面向外模式进行肠系膜动脉平滑肌细胞BKCa单通道记录。结果衰老组 BKCa通道平均开放概率（Po）和平均开放时间显著低于青年组；电压依赖性和钙敏感性亦显著下降；Tamoxifen （1μmol／L）可诱导两组 Po增加，但青年组增加百分比显著高于老年组。结论衰老诱导大鼠肠系膜动脉平滑肌细胞BKCa通道功能下调，以β1亚基功能下调更为显著。
목적：탐토쇠로대대서장계막동맥평활기세포대전도개격활갑통도（BKCa）생물물리특성적영향。방법선용노년조（22～24월령）화청년조（4～5월령）웅성Wistar대서，채용막편겸내면향외모식진행장계막동맥평활기세포BKCa단통도기록。결과쇠로조 BKCa통도평균개방개솔（Po）화평균개방시간현저저우청년조；전압의뢰성화개민감성역현저하강；Tamoxifen （1μmol／L）가유도량조 Po증가，단청년조증가백분비현저고우노년조。결론쇠로유도대서장계막동맥평활기세포BKCa통도공능하조，이β1아기공능하조경위현저。
Objective To investigate the effects of aging on the biophysical properties of large-conductance Ca 2+-activated K+( BK-Ca) channel in rat mesenteric arterial smooth muscle cells .Methods Young (5 months) and Old (22~24 months) male Wistar rats were used.The single channel recording was performed by inside-out patch clamp configuration .Results Electrophysiological recording revealed that aging induced a decrease of the open probability and the mean open time ,but an increase of the mean closed time of BKCa channel .The Ca2+/voltage sensitivity of BKCa channel was also decreased .Application of tamoxifen (1μmol/L) evoked nearly a 5-fold increase in the Po of BKCa channels in Young patches ,while only 1.6-fold increase in Old patches .Conclusions The aging induces functional downregulation of MaxiK channel in MA myocytes ,in which the suppression of β1-subunit function is more pronounced than α-subunit.