摘要
目的证实应激过程中胆汁反流的存在,探讨胆囊收缩素八肽(CCK-8)在应激所致胆汁反流中的作用及相关机制。方法放免法检测大鼠血浆 CCK-8和胃液胆汁酸水平,测定胃液 pH值并记录胃黏膜溃疡指数;多导生理记录仪记录离体肌条收缩活动;检测 Fura-2/AM 标记的胃窦平滑肌细胞(SMC)内钙离子浓度([Ca^(2+)]i)的变化;全细胞膜片钳记录 L-型钙通道电流(I_(Ca-L))。结果与正常对照相比,应激时血浆 CCK-8[从(2.23±0.88)pmol/L 到(10.80±3.82)pmol/L],胃液胆汁酸[从(37.93±23.76)μmol/L 到(1316.00±197.36)μmol/L],pH 值(从1.06±1.20到5.29±1.25)和溃疡指数(从0.62±0.23到32.01±16.11)均明显增高(P<0.01);CCK-8S 显著增强胃窦和幽门肌条收缩和胃窦 SMC 的[Ca^(2+)]i[从(65.8±7.4)nmol/L 升至(472.1±35.6)nmol/L,P<0.01]及 I_(Ca-L)[从(-56.42±6.57)pA 增至(-88.54±5.71)pA,P<0.01],但可被相应拮抗剂所抑制。结论与应激时 CCK-8升高所致的胃窦动力紊乱相关,胆汁反流存在于应激过程中,是应激性胃黏膜损伤的重要因素。
Objective To illustrate the existence of bile regurgitation under stress condition, and explore the possible effects and related mechanism of changes of cholecystokinin octapeptide （ CCK-8 ） on stress-induced bile regurgitation in rats. Methods （1） Changes in plasma CCK-8 and gastric bile concentration were measured by using radioimmunoassay while simultaneously calculating gastric ulcer index and intragastric pH; （2） Each isolated gastric strips were suspended in a tissue chamber to record the contractile responses by polyphysiograph; （3） The responsiveness of gastric smooth muscle cells （SMCs） to sulfated cholecystokinin octapeptide （CCK-8S） were examined using fura-2-1oaded microfluorimetric measurement of intracellular calcium concentration （ [ Ca^2＋ ] i） ; （4） The current of L-type calcium channels （ ICa-L） of SMCs were recorded by patch-clamp techniques. Results （ 1 ） Compared with the normal control, plasma CCK-8 [ from （ 2. 23 ± 0. 88） pmol/L to （ 10. 80 ± 3.82 ） pmol/L ] and gastric bile concentration [ from （37.93 ±23.76） μmol/L to （ 1316. 00 ± 197. 36） μmol/L] significantly increased during the stress （P 〈 0. 01 ） and both simultaneously reached the peak at the time point of 2 h after stress; ulcer index（from 0. 62 ± 0. 23 to 32. 01 ± 16. 11 ） and intragastric pH （ from 1.06 ± 1.20 to 5.29 ± 1.25 ） apparently increased （P 〈 0. 01 ） ; （2） Significant changes to CCK-8S were found in the mean contractile amplitude and frequency of circular muscle and longitudinal muscle of gastric antrum and pylorus; （3） CCK-8S-evoked significant increase in [Ca^2＋]i [from （ 65.8 ±7.4） nmol/L to （472.1 ±35.6）nmol/L, P〈0.01] could be suppressed by CCK-A receptor antagonist; whereas a small but significant increases were still elicited by CCK-8S under condition of the removal of extraeellular calcium; （4） CCK-8S-intensified calcium current ICa-L [ from （ - 56. 42 ± 6. 57 ） pA to （ - 88. 54 ± 5.71 ） pA, P 〈 0. 01 ） ] apparently inhibited by respective administration of nifedipine, Ca^2＋ -ATPase inhibitors or calcium dependent chloride channel blocker （ P 〈 0.01 ）. Conclusions Gastric mucosal damage induced by bile regurgitation is closely connected with gastric antrum and pylorus dysmotility evoked by CCK-8 during the stress. CCK-8S-evoked [ Ca^2＋ ] i increase in gastric antrum and pylorus SMC depends on the release of intracellular calcium stores which activates L- type voltage-dependent calcium channels through the activation of calcium dependent chloride channels.
出处
《中华内科杂志》
CAS
CSCD
北大核心
2006年第10期827-830,共4页
Chinese Journal of Internal Medicine
关键词
缩胆囊素
应激
胆汁反流
Cholecystokinin
Stress
Bile regurgitation
