一氧化氮和前列腺素在门静脉高压性胃病大鼠胃粘膜灌注中的作用

目的 探讨一氧化氮（NO）和前列腺素在门静脉高压性胃病（PHG）大鼠胃粘膜灌注中的作用。方法 部分结扎大鼠门静脉主干2周后，采用中性红清除率法测定大鼠胃粘膜血流量（GMBF），同时观察门静脉压力（PVP）的变化。结果 PHG组大鼠GMBF和PVP显著高于假手术组（t=3.431、3．312，P＜0．01）。低剂量的NO合成酶抑制剂L－硝基－精氨酸甲酯（L－NAME）呈剂量依赖性降低PHG大鼠GMBF，而对假手术组GMBF无明显影响；高剂量的L－NAME（12mg/kg)能非常显著降低PHG和假手术组大鼠GMBF。前列腺素环氧合酶抑制剂消炎痛能明显降低PHG组大鼠GMBF，而对假手术组GMBF无明显影响；预先给消炎痛处理后在假手术组大鼠中，静脉注射低剂量L－NAME（4mg/kg)前后GMBF无明显变化，高剂量L－NAME（12mg/kg)降低大鼠的GMBF与未用消炎痛处理组比无明显变化；预先给消炎痛处理后在PHG组大鼠中，L－NAME剂量（4mg/kg、12mg/kg)依赖性降低大鼠的GMBF与未用消炎痛处理组比无明显改变。结论 NO、前列腺素在调节PHG大鼠的GMBF起重要作用，但两者无协同作用。

Effects of nitric oxide and prostaglandin on gastric mucosal perfusion in rats with portal hypertensive gastropathy

Objective To observe the effects of nitric oxide (NO) and prostaglandin on gastric mucosal perfusion in rats with portal hypertensive gastropathy (PHG). Methods Two weeks after partial portal vein ligation, gastric mucosal blood flow (GMBF) was measured with the neutral red clearance method and the changes of portal venous pressure (PVP) were observed. Results GMBF and PVP were significantly higher in rats with PHG than in sham operated rats (P<0.01). Low dose inhibitor of NO synthesis Nw -nitro-L-arginine methyl ester (L-NAME 1mg/kg, 4mg/kg) caused a significant and dose dependent reduction in GMBF in PHG rats, but had no effect on sham operated rats. High dose L-NAME (12 mg/kg) significantly decreased GMBF in both PHG and sham operated rats. The inhibition of prostaglandin synthesis with indomethacin significantly decreased GMBF in rats with PHG, but had no effect in sham operated rats. In sham operated rats pretreated with indomethacin, GMBF was not modified after and before injection of low dose L-NAME (4mg/kg); likewise, high dose of L-NAME (12 mg/kg) did not alter the significant reduction ic GMBF as compared with pretreatment without indomethacin. In PHG rats the significant dose dependent reduction in GMBF induced by L-NAME (4mg/kg, 12mg/ kg) was not significantly different between pretreatment with and without indomethacin. Conclusions NO and prostaglan- dins play an important role in the regulation of GMBF in rats with PHG, but no synergistic interactions between them.