Abstract

The objective of this study is to investigate the relationship between altered plasma trace elements, particularly selenium (Se), with Hyper-homocysteinemia (HhCys) as a predictive factor of insulin secretion dysfunction. The study is carried out on adult Psammomys obesus, divided in 4 experimental groups: (I) Normoglycemic/Normoinsulinemic; (II) Normoglycemic/Hyperinsulinemic; (III) Hyperglycaemic/Hyperinsulinemic and (IV) Hyperglycaemic/Insulin deficiency with ketoacidosis. The data showed that a drastic depletion of Se plasma levels is positively correlated with HhCys (>15 µmol/L; p < .001), concomitantly with decreased GPx activity, GSH levels, and GSH/GSSG ratio in group IV both in plasma and liver. In contrast, SOD activity is increased (p ≤ .001) in group IV both in plasma and liver. However, plasma Cu and Mn levels increased, while plasma Zn levels decreased in group IV (p < .001). Our study confirms the increase of plasma hCys levels seemed to be a major contributing factor to antioxidant capacities and alters the availability of selenium metabolism by interference with homocysteine synthesis in the insulin secretion deficiency stage.

摘要

本研究的目的是研究改变的血浆微量元素（尤其是硒 (Se)）与高同型半胱氨酸血症 (HhCys) 之间的关系，作为胰岛素分泌功能障碍的预测因素。该研究是在成年Psammomys obesus上进行的，分为 4 个实验组：(I) Normoglycemic/Normoinsulinemic；(II) 正常血糖/高胰岛素血症；(III) 高血糖/高胰岛素血症和 (IV) 高血糖/胰岛素缺乏伴酮症酸中毒。数据显示，Se 血浆水平的急剧消耗与 HhCys 呈正相关（>15 µmol/L；p  < .001），伴随着血浆和 IV 组中 GPx 活性、GSH 水平和 GSH/GSSG 比率的降低肝。相反，SOD 活性增加（p ≤ .001) IV 组血浆和肝脏。然而，IV 组的血浆铜和锰水平升高，而血浆锌水平降低 ( p  < .001)。我们的研究证实，血浆 hCys 水平的增加似乎是抗氧化能力的主要促成因素，并通过干扰胰岛素分泌不足阶段的同型半胱氨酸合成来改变硒代谢的有效性。