铁皮石斛降血糖作用及其机制的研究

目的 :研究铁皮石斛的降血糖作用及其机制。方法 :采用正常小鼠 ,肾上腺素性高血糖小鼠 ,链脲佐菌素性糖尿病 (STZ-DM)大鼠 ,用放射免疫分析和免疫组化HRP-SPA染色等方法进行研究。结果 :铁皮石斛对正常小鼠血糖及血清胰岛素水平无明显影响 ,但可使STZ-DM大鼠的血糖值降低、血清胰岛素水平升高、胰高血糖素水平降低。免疫组化染色显示 ,给药大鼠胰岛 β细胞数量增多 ,α细胞数量减少。它还可使肾上腺素性高血糖小鼠血糖降低、肝糖原含量增高。结论 :铁皮石斛对肾上腺素性高血糖小鼠及STZ-DM大鼠有明显的降血糖作用。其降血糖的胰内机制是促进胰岛 β细胞分泌胰岛素 ,抑制胰岛α细胞分泌胰高血糖素 ,胰外机制可能是抑制肝糖原分解和促进肝糖原合成。

Studies on anti-hyperglycemic effect and its mechanism of Dendrobium candidum

OBJECTIVE: To study the anti-hyperglycemic effect and its mechanism of Dendrobium candidum (DC). METHOD: Normal mice, adrenaline-induced hyperglycemic mice, streptozotocin-induced diabetic (STZ-DM) rats were used. The mechanisms of the anti-hyperglycemic action were studied with radio-immunoassay, immunohistochemical HRP-SPA stain, etc. RESULT: DC could not obviously decrease the serum glucose concentrations and insulin levels in normal mice. It could increase serum insulin levels and decrease serum glucagons concentrations in STZ-DM rats. The results of immunohistochemical stain demonstrated that the number of islet beta cells was increased and that of islet a cells was decreased in STZ-DM rats. It could also decrease the serum glucose concentrations and increase liver glucogen contents in adrenaline-induced hyperglycemic mice. CONCLUSION: DC has obvious anti-hyperglycemic effects in adrenaline-induced hyperglycemic mice and STZ-DM rats. Its mechanisms are stimulating the secretion of insulin from beta cells and inhibiting the secretion of glucagons from a cells, and it can probably decrease the decomposition of liver glucogen and increase the synthesis of liver glucogen.