同型半胱氨酸对大鼠局灶性脑缺血后血管再生的影响

Effects of homocysteine on post-cerebral ischemic angiogenesis in rats

目的探讨同型半胱氨酸(Hcy)对大鼠局灶性脑缺血后梗死灶周围区血管再生的影响,为明确血管再生的抑制因素,促进大脑功能恢复奠定临床基础。方法将36只清洁级(SD)雄性大鼠随机分为3组:假手术组(SO组)、大脑中动脉闭塞(MCAO)模型组(MCAO组)、MCAO+Hcy组,每组12只,SO组和MCAO组腹腔注射生理盐水5 m L/(kg·d),MCAO+Hcy组腹腔注射2%Hcy溶液5 m L/(kg·d),预干预7 d后采用线栓法制作MCAO模型,于术后第7天处死取材,取材前3 d通过腹腔连续注射5-溴脱氧尿嘧啶核苷(BrdU)。通过高效液相色谱(HLPC)法检测大鼠血清中Hcy浓度,TTC染色观察脑组织梗死灶区面积大小,采用免疫荧光染色法检测梗死侧丘脑Brd U^+/lamini+细胞数目。结果 MCAO+Hcy组大鼠血清Hcy浓度较SO、MCAO组显著增高,脑组织梗死面积较MCAO组大,丘脑内Brd U^+/laminin+细胞数目较MCAO组减少(P<0.05)。结论体内Hcy浓度增高可增强脑梗死的损伤程度,并且抑制缺血区周围部位的血管再生。

Objective To explore the role of homocysteine （Hey） on angiogenesis at peri infarct region after focal cere- bral ischemia in rats, to elucidate inhibitory factors of angiogenesis, and to establish a clinic foundation for clinical brain functional recovery. Methods Spragur-Dawley （SD） male rats （n=36） were randomly divided into three groups with 12 rats in each group including Sham Operation （SO） group, Middle cerebral artery occlusion （MCAO） group and MCAO＋Hcy group; The rats in Sham and MCAO groups were intra-peritoneally injected with 5 mL/（kg, d） saline and rats in MCAO ＋ Hey group were injected with 2% 5 mL/（kg- d） Hey solution from the same route. MCAO was introduced by intraluminal filament meth- od after 7 d Hcy intervention. Rat brains were harvested on the 7＇h day after MCAO. BrdU （50 mg/kg, as a marker of cell pro- liferation） was intraperitoneally injected three days before the rats were killed. High performance liquid chromatography （HPLC） was used to measure serum Hey concentration in rats. Brain infarction size was observed by TFC staining. Immuno- fluorescence staining was used to detect the number of BrdU^＋/laminin^＋ cells at the thalamus of infarction side. Results Se- rum Hey concentration significantly higher in MCAO ＋ Hey group than in SO and MCAO groups （P 〈 0.05）. Brain damage increased and the number of BrdU ＋/laminin＋ cells decreased in MCAO ＋ Hcy group compared with those of MCAO group （P 〈 0.05）. Conclusion Increased Hcy concentration in rats lead to more severe damage of cerebral infarction as well as to inhibit the angiogenesis at surrounding ischemia area.