胰岛素、胰岛素原对胰岛素抵抗状态下HepG2细胞PAI-1分泌的影响

目的研究胰岛素、胰岛素原对胰岛素抵抗状态下ＨｅｐＧ２细胞ＰＡＩ１分泌的影响。方法选择在合成ＰＡＩ１方面与肝细胞相似的ＨｅｐＧ２细胞，以高浓度胰岛素诱导胰岛素抵抗后，分别用生理浓度的胰岛素、胰岛素原刺激２４小时，以观察胰岛素抵抗状态下ＰＡＩ１活性的变化。结果基础状态下胰岛素抵抗ＨｅｐＧ２细胞与非胰岛素抵抗ＨｅｐＧ２细胞相比，ＰＡＩ１活性差异不明显；胰岛素、胰岛素原刺激后，胰岛素抵抗ＨｅｐＧ２细胞ＰＡＩ１活性明显高于非胰岛素抵抗ＨｅｐＧ２细胞。当培液中同时加入１０－４Ｍ二甲双胍后，胰岛素、胰岛素原介导的ＰＡＩ１过量分泌得到明显抑制。结论在胰岛素抵抗状态下，胰岛素、胰岛素原刺激后ＨｅｐＧ２细胞ＰＡＩ１活性明显增加，而二甲双胍可明显抑制此现象。

Changes of bone mineral density and biochemical markers of bone turnover in patients with hyperthyroidism

Objective To assess changes in bone mineral density (BMD) and bone turnover in hyperthyroidism. Methods BMD of lumbar spine (L 2 L 4) and the proximal femur was measured with dual energy X ray absorptiometry (DEXA) in 81 untreated hyperthyroid patients and 81 healthy subjects matched for age, sex and menopausal status. Biochemical markers of bone turnover such as osteocalcin (OSC), bone specific alkaline phosphatase (BAP) and carboxy terminal propeptide of type I procollagen (PICP) and carboxy terminal cross linked telopeptide of type I collagen (ICTP), PTH and 25 hydroxy vitamine D (25 OH D) were also measured. Results BMD values (g/cm 2) in hyperthyroid patients decreased significantly as compared with healthy subjects (P<0.001). Serum concentrations of bone formation markers (OSC, BAP and PICP) and bone resorption marker (ICTP) were significantly higher in hyperthyroid patients than in healthy subjects (P<0.001). Serum PTH and 25 OH D levels were normal. Highly significant positive correlation was seen between bone formation markers (r=0.42 0.59,P<0.001,n=81) and between ICTP and bone formation markers (r=0.35 0.41,P<0.001,n=81). No significant correlation was found between Z score of BMD and serum levels of biochemical markers of bone turnover (P>0.05). Conclusion There are reduction in BMD of lumbar spine and proximal femur and high bone turnover in hyperthyroidism.