微量水溶性维生素对胰岛素分泌的影响

Different effects of low dosage of water-soluble vitamins on insulin secretion of rats

目的研究各种微量水溶性维生素对胰岛素分泌的影响。方法每种水溶性维生素和混合的B族维生素配制成浓度为0、0.05、0.25、0.5和1μmol/L的不同维生素溶液,将维生素溶液添加于含葡萄糖0、8.3和16.7 mmol/L的大鼠胰岛培养液中,孵化90 min后测定胰岛素分泌量。结果维生素B_1和维生素B_6在0.25～1μmol/L浓度范围内对胰岛素分泌没有影响;生物素和泛酸在16.7 mmol/L的葡萄糖浓度条件下能刺激胰岛素的分泌;烟酸在16.7 mmol/L葡萄糖浓度条件下对胰岛素分泌有刺激作用,在8.3 mmol/L葡萄糖浓度条件下则抑制胰岛素的分泌;叶酸、维生素C、维生素B_2以及混合B族维生素在16.7 mmol/L葡萄糖浓度条件下抑制胰岛素的分泌。结论水溶性维生素对胰岛素分泌的作用各不相同,胰岛素分泌量依赖于葡萄糖和维生素的浓度。糖尿病患者应该注意食物中水溶性维生素的摄入。

Objective The aim of this study was to investigate systematically the effects of water-soluble vitamins on the insulin secretion of rats in vitro. Methods The pancreatic islets from rats were incubated in media containing different concentrations of D-glucose and various vitamins for 90 rain and insulin secretion was measured. Results In the concentration ranged from 0.25 to 1 μmol/L, B1 and B6 had no effects on insulin secretion. Biotin and pantothenic acid could stimulate insulin secretion at the concentration of 16.7 mmol/L of D-glucose. Nicotinic acid had different effects on insulin secretion at different concentrations of D-glucose. In brief, at 16.7 mmol/L of D-glucose, nicotinic acid stimulated insulin secretion while at 8.3 mmol/L of D-glucose, nicotinic acid had opposite effects. Folic acid, vitamin B2, the mixture of B vitamins and vitamin C inhibited insulin secretion at 16.7 mmol/L of D-glucose to various extents. Conclusion Different vitamins at different concentrations could affect the insulin secretion from islets of rats in vitro. Patients with diabetes must select vitamins carefully as nutrient foods.