| Research Abstract |
1.Organ culture of rat thoracic rings for 24h resulted in the increased expression of embryonic form of fibronectin and disappearance of the expression of a-actin. This result suggests the phenotypic change in the vascular smooth muscle cells from contractile type to synthetic type by incubation. Furthermore, induction of c-fos, c-myc, and heat shock protein 70 were observed prior to the expression of fibronectin. Genestin, a specific inhibitor of tyrosine kinase, and staurosporine, a specific inhibitor of protein kinase C,suppressed the induction of c-fos, c-myc, HSP70 and fibronectin, completely. These results suggest the involvement of tyrosine kinase and protein kinase C in the phenotypic changes of the vascular smooth muscle cells
2.Incubation of the human umbrionic venous endothelial cells (HUVEC) in the high glucose medium (5.5,16.5,33.0,55.0 mM of glucose) for 24h resulted in the increased adhesion of THP-1 cells to HUVEC compared with the osmotic control (high mannnitol medium) dose dependently. Incubation with 300mg/ml of LDL or VLDL did not change the adhesion of the THP-1 cells to HUVEC,but preincubation with high glucose medium increased the expression of adhesion molecule induced by LDL or VLDL.High glucose medium also increased the response of the adhesion to lyso-phosphatidylcholine. Glycoxylated LDL or VLDL alone did not increase the adhesion, but high glucose medium modified the response of HUVEC by increasing the adhesion. These resuts imply the role of TG-rich VLDL in the induction of the adhesion molecule in HUVEC.
3.Hypercholestenemia is widely recognized as the atherogenic factor, but the role of the hypertriglycemia alone in the atherogenecity remains to be unclear. We measured the carotid intimal-medial thickness of the diabetic patients by B-mode ultrasonography. Multiple regression analysis showed the risk factor for carotid IMT are age, sex, non-HDL cholesterol and systolic blood pressure, but not triglyceride.
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