内皮素-1对豚鼠远端结肠上皮离子转运作用的研究  

Study of the Effects of Endothelin 1 on Ion Transport in Guinea Pig Distal Colon

作　　者：刘维新[1] 徐永泉[2] 傅宝玉[1] 花井洋行 王彦[4] 

机构地区：[1]中国医科大学第一临床学院消化内科,沈阳110001 [2]中国医科大学第二临床学院内科 [3]日本浜松医科大学附属病院第一内科 [4]中国医科大学84期英文班

出　　处：《中国医科大学学报》2001年第4期251-253,共3页Journal of China Medical University

摘　　要：目的 :研究内皮素 1(endothelin 1,ET 1)对豚鼠远端结肠上皮离子转运的作用。方法 :用UssingCham ber检测ET 1在不同离子阻断剂存在下对豚鼠远端结肠上皮的短路环状电流 (shortcircuitcurrent ,Isc)和上皮间传导性 (transepithelialconductance ,Gt)的影响来测定ET 1对结肠上皮的K+、Na+、Cl-离子转运的作用。结果 :浆膜侧 10 -810 -6 mol/LET 1可引起Isc双相性改变 (Isc先升高而后降低 )并伴有Gt的增加 ,10 -9mol/LET 1可引起Isc降低同时伴有Gt的增加。ET 1所致Isc和Gt改变呈浓度依赖性 ,Isc的升高和Gt的增加可被DPC、浆膜侧无氯溶液及ETA 受体拮抗剂BQ4 85所抑制 ,提示ET 1可引起豚鼠远端结肠上皮Cl-的分泌 ;而Isc降低伴有Gt增加可被bumetinade、粘膜侧高K+溶液及TEA所抑制 ,也可被ETA 和ETB 受体拮抗剂BQ4 85、BQ788抑制Isc降低和Gt增加 ;Tetrodotoxin不能影响ET 1所引起的Isc和Gt改变 ,但用Indomethacin处理或在无Ca2 +溶液环境下 ,ET 1所引起的Isc和Gt改变均消失。结论 :ET 1可直接作用于粘膜上皮细胞与ETA 或ETB 受体结合刺激豚鼠远端结肠上皮分泌K+和Cl-,这种作用可能由前列腺素介导 ,对细胞外钙有依赖性。Objective: Our aim was to study the effects of endothelin 1 (ET 1) on ion transport in distal colon mucosa of guinea pig and the mechanism. Methods: We used Ussing chamber to measure the short circuit current (Isc) as well as the transepithelial conductance (Gt) with electrophysiological and pharmacological approaches. Results: Serosally ET 1 (more than 10 -9 mol/L) could cause biphasic changes of Isc (initially increase then decrease) with increases in Gt in the presence of mucosal amiloride. The increase in Isc and Gt were dose dependent and were inhibited by a chloride channel blocker mucosal diphenylamine 2 carboxylate (DPC). Indomethacin and calcium removal from serosal solution inhibited increase in Isc. Decrease in Isc and increase in Gt were inhibited by bumetanide and high potassium solution. ET A receptor antagonist BQ485 could inhibit the increase in Isc and increase in Gt produced by ET 1. Both BQ485 and ET B receptor antagonists BQ788 could inhibit the decrease in Isc produced by ET 1. Conclusion: The ET 1 stimulates electrogenic potassium and chloride secretion in guinea pig distal colon. These effect, especially in chloride secretion, may be mediated by prostaglandins. Extracellular calcium might be necessary for the effect. ET A receptor mainly regulate chloride secretion.

关 键 词：内皮素 离子转运 结肠 结肠上皮 

分 类 号：R322.45[医药卫生—人体解剖和组织胚胎学]