摘要目的 观察褐藻胶寡糖(AOS)对野百合碱诱导的大鼠肺动脉高压模型P选择素表达的影响.方法 60只雄性SD大鼠根据随机数字表法分为对照组、模型组、前列地尔组、褐藻胶寡糖低剂量(AOS-L)组、褐藻胶寡糖中剂量(AOS-M)组及褐藻胶寡糖高剂量(AOS-H)组,每组10只,采用一次性腹腔注射野百合碱(60 mg/kg)的方法建立肺动脉高压模型.造模成功后,前列地尔组腹腔注射前列地尔5μg·kg-1 ·d-1,AOS-L组、AOS-M组及AOS-H组分别腹腔注射褐藻胶寡糖5、10及20mg·kg-1·d-1.对照组与模型组每天腹腔注射0.9％氯化钠溶液3 ml/kg.记录大鼠的死亡情况.给药3周后,测定大鼠的肺动脉血流加速时间(PAT)、肺动脉射血时间(ET)及肺动脉内径值.分离大鼠心脏,计算大鼠的右心室肥厚指数(RVHI)并观察肺组织病理.采用酶联免疫吸附试验和Western blot法分别测定血浆和肺动脉P选择素的表达情况.结果 与对照组比较,模型组病死率较高.模型组RVHI(0.677±0.047)高于对照组,PAT/ET(0.179 ±0.008)低于对照组(均P＜0.01).AOS-L组、AOS-M组及AOS-H组大鼠生存情况较模型组明显改善,RVHI明显低于模型组,分别为0.539±0.049、0.502±0.034、0.446±0.045(均P＜0.01),PAT/ET明显高于模型组,分别为0.170±0.023、0.231±0.053、0.351±0.369(均P＜0.05).组织病理学可见模型组肺中小动脉内皮细胞连续性破坏,管壁厚度增加,管腔面积缩小,伴有明显的血管周围炎,管腔内可见原位血栓形成,肺泡内可见心力衰竭细胞.AOS组血栓形成减少,血管周围炎症减轻.与对照组比较,模型组血浆和肺动脉中P选择素的表达明显增高(JP＜0.01),AOS组P选择素的表达降低(P＜0.01).结论 AOS降低野百合碱诱导的大鼠肺动脉高压模型P选择素的表达,该作用呈浓度依赖性.

abstractsObjective To observe the effects of acidic oligosaccharides (AOS) on P-selectin levels in the serum and the pulmonary arteries of pulmonary hypertensive rats induced by monocrotaline.Methods Sixty healthy adult male Sprague-Dawley rats were randomly divided into control group (n =10),model group (n =10),Alprostadil group (n =10),low-dose AOS group (AOS-L,n =10),medium-dose AOS group (AOS-M,n =10) and high-dose AOS group (AOS-H,n =10).The rat model of pulmonary arterial hypertension was made by a single intraperitoneal injection of monocrotaline(60 mg/kg).Five weeks after injection,pulmonary arterial (PA) acceleration time (PAT) and ejection time (ET) were measured by color Doppler ultrasound.Then,the Alprostadil group was treated by Alprostadil 5 μg · kg-1 · d-1 intraperitoneally.Acidic oligosaccharides was administered by intraperitoneal injection to rats in the AOS-L group(5 kg-1 · d-1),AOS-M group (10 mg· kg-1 · d-1)and AOS-H group (20 mg· kg-1 · d-1).Control group and model group were given normal saline instead.At the end of experiments,the death rate was recorded and PAT/ET was measured.We calculated the right ventricular hypertrophy index (RVHI) of all rats sacrificed under anesthesia.Precision-cut lung slices were stained with HE for observation of the structure of middle and small arteries.The expression level of P-selectin in serum and pulmonary arterial tissues were detected by ELISA and Western blot respectively.Results AOS significantly increased the level of PAT/ET (P ＜ 0.01),and attenuated RVHI (P ＜ 0.01).AOS significantly improved intima-media proliferation in small-to medium-sized pulmonary arteries,and attenuated perivascular inflammation.AOS and Alprostadil significantly down-regulated the protein expression of P-selectin in serum and pulmonary arteries (P ＜ 0.01).Conclusion In this rat model of monocrotaline-induced pulmonary hypertension,AOS decreased the expressions of P-selectin in serum and pulmonary arteries in a dose-dependent manner.