松花粉对糖尿病肾病小鼠肾脏损伤的保护作用

 探讨松花粉对链脲霉素（streptozotocin，STZ）诱导糖尿病肾病小鼠肾脏损伤的保护作用及可能机制。成年雄性C57BL/6J（Wild Type）小鼠50 只，采用STZ 诱导糖尿病肾病小鼠动物模型。实验小鼠随机分为正常对照组（10 只）、STZ 模型组（40只）；STZ 模型组按150 mg/kg 腹腔注射STZ 一次，复制小鼠糖尿病肾病模型，对照组小鼠则腹腔注射柠檬酸钠缓冲液。在造模1周后，小鼠空腹血糖值大于11.1 mmol/L 视为糖尿病诱导成功，此后定期每周监测血糖和24 h 尿蛋白，持续出现蛋白尿的小鼠视为成模小鼠。成模糖尿病肾病小鼠28 只，将其随机分为STZ 模型组和松花粉治疗组各14 只；松花粉治疗组每天给予750 mg/kg体重的松花粉灌胃，正常对照组与STZ 模型组以等体积的0.9%氯化钠注射液灌胃。连续7 周后，检测小鼠血糖、24 h 尿微量白蛋白、尿肌酐、血肌酐、血浆尿素氮水平；计算肾重/体重比、肾脏组织丙二醛（MDA）含量等指标，并对肾脏组织切片行Masson 和Jones 六胺银染色；Western Blot 的方法观察p38 和ERK 信号分子的磷酸化激活情况。与模型组相比，松花粉治疗组肾重/体重比、肾小球细胞外基质增生程度和肾功能损害程度均明显减轻；松花粉能够降低糖尿病肾脏的MDA 含量并抑制p38 和ERK 信号分子的激活。由此可以看出，松花粉能通过抑制p38 和ERK 信号分子的磷酸化激活，减轻肾脏的氧化损伤和肾小球细胞外基质增生。

Protective Effect of Pine Pollen on Mice Renal Damage in a Model of Diabetic Nephropathy

This paper studies the protective effect of pine pollen on renal damage in a mouse model of diabetic nephropathy and its mechanism. Fifty adult male C57BL/6J mice were used, and the mouse model of diabetic nephropathy was induced by streptozotocin (STZ). The mice were randomly divided into the control group (n=10) and the STZ model group (n=40). The latter received intraperitoneal injection of a single high dose of 150 mg body weight of STZ dissolved in citrate buffer to induce diabetic nephropathy. The control group were injected with sodium citrate buffer alone. Glucose concentrations in the tail vein blood of the mice were measured 1 week after STZ administration. Only STZ-injected mice with fasting blood glucose concentrations >11.1 mmol/L were included in the diabetic groups. After that, blood glucose and urine protein were detected in 24 hours regularly, and mice with continuing albuminuria were regarded as those with diabetic nephropathy, which totaled 28. The 28 mice were randomly divided into the STZ model group (n=14) and the pine pollen group (n=14). Mice in the pine pollen group were given pine pollen (750 mg) daily. Meanwhile, enema was performed using equal volume of normal saline in the control and STZ model groups. 7 weeks later, plasma glucose concentration, 24 h urinary protein excretion, urine creatinine, serum creatinine and plasma urea nitrogen were detected. The renal tissue was collected to assay the renal weight/body weight ratio and relative level of MDA. Masson staining and Silver staining were performed for histological analyses. The expression of p-p38 and p-ERK in renal cortical tissues was examined using Western Blot. Compared with that in the STZ model group, pine pollen apparently ameliorated renal functional lesion, reduced the renal weight/ body weight ratio and extracellular matrix accumulation. Pine pollen can also reduce the level of MDA and inhibit the activation of p38 and ERK in diabetic kidney. The results showed that pine pollen may reduce oxidative damage of the kidney and extracellular matrix accumulation by inhibiting the phosphorylation level of p38 and ERK in renal cortical tissues.