rhIGF-1对STZ糖尿病大鼠心肌局部血管紧张素Ⅱ的影响

Effects of Recombinant Human IGF-1 on Cardiac Angiotensin Ⅱ in STZ-DM Rats

目的 观察重组人胰岛素样生长因子 1(rhIGF 1)对链脲佐菌素 (STZ)糖尿病大鼠心肌局部钙和血管紧张素Ⅱ(ATⅡ)含量的影响 ,探讨其对糖尿病心肌病变的潜在治疗价值。方法 STZ 5 5mg/kg腹腔注射建立糖尿病大鼠模型 ,随机分为糖尿病对照组 (DM C)和糖尿病治疗组 (DM rhIGF 1) ,并设立未予任何处理的正常对照组 (NC) ,6周后测定大鼠血糖、果糖胺 (FMN)、血清GH和IGF 1水平、心肌Ca2 + 和ATⅡ含量及Ca2 + ATP酶活性。结果 (1)rhIGF 1治疗降低DM大鼠血糖和果糖胺水平 ;(2 )rhIGF 1治疗降低DM大鼠血清GH水平 ,升高IGF 1含量 ;(3)rhIGF 1治疗降低DM大鼠心肌局部Ca2 + 含量 ,升高Ca2 + ATP酶活性 ,降低ATⅡ含量。结论 rhIGF 1治疗改善STZ糖尿病大鼠心肌病变 ,可能与改善全身代谢及降低心肌局部ATⅡ含量有关。

Purpose To investigate the effects of rhIGF?1 on the levels of cardiac Ca 2+ and angiotensin Ⅱ(ATⅡ) in STZ induced diabetic rats,so as to clarify the potential benefit of rhIGF?1 on diabetic cardiomyopathy. Methods Diabetic rats were induced by intraperitoneal injection(IP) of STZ at the dosage of 55 mg/kg in male SD rats and the diabetic rats were divided into two groups:DM?C group(treated with NS 0.1 mL·d -1 ,IP) and DM?rhIGF?1 group(treated with rhIGF?1,750 ng·kg -1 ·d -1 ,IP).Normal control(NC) group did not receive any therapy.The experiment lasted 6 weeks.The blood glucose and fructosamine(FMN) levels were determined.Serum GH and IGF?1 levels were measured by RIA method.The cardiac tissue were analyzed for the levels of Ca 2+ ,ATⅡ and the activity of Ca 2+ ?ATPase. Results (1) Compared with NC group,DM?C group had higher levels of blood glucose and FMN.The levels of blood glucose and FMN of DM rhIGF?1 group were lower than those of DM?C group( P <0.01),but higher than those of NC group( P <0.01).(2) The serum content of GH of DM rhIGF?1 group was lower than that of DM?C group.And the level of IGF?1 was higher than that of DM?C group.(3) Compared with DM?C group,the contents of cardiac Ca 2+ and ATⅡ were lower and the activity of Ca 2+ ?ATPase was higher in DM rhIGF?1 group. Conclusions rhIGF?1 can improve diabetic cardiomyopathy.It may be due to its beneficial effect on general metabolism and its decreasing effect on cardiac content of ATⅡ.