氨基胍抑制氨基脲敏感性胺氧化酶活性对糖尿病大鼠血管并发症的预防作用

Aminoguanidine Prevents Vascular Complications by Inhibiting Semicarbazide Sensitive Amine Oxidase Activity in Diabetic Rats

目的探讨氨基胍在体内外对氨基脲敏感性胺氧化酶(SSAO)的抑制效果及对糖尿病大鼠血管并发症的预防作用。方法取雄性SD大鼠主动脉匀浆作为SSAO酶样来源,体外应用苯甲胺作为SSAO催化底物,在酶促反应体系中加入一系列浓度的氨基胍,采用高效液相色谱法检测SSAO活性;取雄性SD大鼠35只,随机分为正常对照组、糖尿病模型组(DM组)和氨基胍干预组(DM+氨基胍组),采用单次腹腔注射链脲佐菌素建立糖尿病模型,DM+氨基胍组腹腔注射氨基胍25 mg/(kg·d)。8周末检测大鼠血浆SSAO活性、甲胺、甲醛、内皮素1(ET-1)、一氧化氮(NO)浓度,同时检测主动脉组织SSAO活性,HE染色及透射电镜分别观察大鼠胸主动脉、肾组织形态学改变。结果氨基胍对大鼠主动脉组织SSAO具有较强的抑制作用,IC50为12.47μmol/L;DM组SSAO活性、ET-1浓度高于正常对照组,血浆NO浓度低于正常对照组(P<0.01);氨基胍明显抑制糖尿病大鼠SSAO活性,降低ET-1浓度,升高甲胺、NO浓度(P<0.01);DM+氨基胍组主动脉、肾组织病理改变较DM组明显减轻。结论氨基胍可有效抑制SSAO活性,可通过抑制SSAO氧化脱氨作用预防糖尿病血管并发症。

Aim To investigate aminoguanidine （AG） inhibitory effect on semicarbazide-sensitive amine oxidase （SSAO） in vitro and in viva, and the prevention of vascular complications in diabetic rats. Methods SSAO enzyme from aorta homogenates of male SD rats, benzylamine was used as artificial substate for the catalytic reaction of SSAO. A series concentration of AG were added in the enzymatic reaction system, using high performance liquid chromatography to detect SSAO enzyme activity. 35 male SD rats were randomly divided into normal control （NC） group, diabetic model （DM） group and DM ＋ AG group, using a single intraperitoneal injection of streptozotocin （STZ） induced diabetic model, AG （25 mg/kg） was administered daily via intraperitoneal injection in DM ＋ AG group. Plasma SSAO enzyme activity, methylamine, formaldehyde, endothelin-1 （ET-1）, nitric oxide （NO） were detected after 8 weeks later, while aortic tissue SSAO enzyme activity was detected. Morphology of aorta and kidney in all groups were observed under light microscope and transmission electron microscope. Results AG was strongly inhibited rat aortic tissue SSAO enzyme activity, ICs0 was 12.47 μmol/L. SSAO enzyme activity, ET-1 concentration in DM group were higher than those in NC group while plasma NO concentration was decreased （ P 〈 0. 01 ）. AG can strongly inhibit SSAO enzyme activity in diabetic rats, re-duce ET-1 level, elevate methylamine, NO concent2ration （P 〈 0. 01 ）. The pathological changes of aorta and kidney in DM ＋ AG group were less serious than DM group. Conclusion AG can effectively inhibit SSAO enzyme activity. The preventive effect of AG on diabetic vascular complications may inhibit SSAO oxidative deamination effect.