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利用全细胞膜片钳技术 ,在用胶原酶急性分离的豚鼠胃窦环行肌细胞上观察了外源性花生四烯酸 (arachidonicacid ,AA)及其它不饱和脂肪酸对容积敏感氯电流 (volume sensitivechloridecurrent,VSCC)的影响。细胞膜电位钳制在- 6 0mV条件下 ,低渗性细胞膨胀激活VSCC。当给予按 2 0mV间隔的去极化阶跃性方波刺激时 ,VSCC的电流 电压曲线具有外向性整流的特点 ,并表现出去极化到 +40mV以上时呈现时间依赖性衰减的特点。AA呈齐量依赖性地抑制VSCC ,而对VSCC的随时间衰减部分的抑制效应更明显。其它不饱和脂肪酸 ,如含有 2个双键的亚油酸 (Linoleicacid,LA)、含有 1个双键的油酸 (Oleicacid ,OA)也抑制VSCC ,抑制强度顺序为AA >LA >OA ,但饱和脂肪酸 (stearicacid,SA)对VSCC无抑制作用。提示外源性不饱和脂肪酸抑制VSCC ,其抑制效应在VSCC的随时间衰减部分更明显。外源性不饱和脂肪酸对VSCC的抑制作用可能与脂肪酸链中的双键数目有关
Whole cell patch clamp technique was used to observe the effects of arachidonic acid (AA) and other unsaturated fatty acids on volume sensitive chloride current (VSCC) in antral myocytes of guinea pigs isolated acutely with collagenase. )Impact. Cell membrane potential clamp at -6 0mV conditions, hypotonic cell expansion activated VSCC. When given depolarization step-square wave stimulation at 20 mV intervals, the current-voltage curve of VSCC is characterized by outward rectification and shows a time-dependent attenuation of depolarization above +40 mV. AA suppresses VSCC in a dose-dependent manner, whereas the inhibitory effect on VSCC over time is more pronounced. Other unsaturated fatty acids, such as linoleic acid (LA) containing two double bonds and oleic acid (OA) containing one double bond, also inhibited VSCC and the order of inhibition was AA> LA> OA but saturated Fatty acids (stearic acid, SA) have no inhibitory effect on VSCC. It is suggested that the inhibitory effect of exogenous unsaturated fatty acid on VSCC is more obvious in VSCC over time. The inhibitory effect of exogenous unsaturated fatty acids on VSCC may be related to the number of double bonds in the fatty acid chain