High Glucose, but Not Testosterone, Increases Platelet Aggregation Mediated by Endothelial Cells

Abstract

Endothelial cells inhibit platelet aggregation by releasing thromboregulators, such as prostacyclin and nitric oxide. Male subject is a traditional risk factor for cardiovascular diseases. Platelet hyperreactivity has been frequently found in patient with diabetes mellitus. To examine whether testosterone and high glucose modify platelet aggregation through endothelial cells, we did an in vitro study using endothelial cells culture from human umbilical vein (HUVEC). Treatments were performed in HUVEC sub culture as either normoglucose (5.6 mM) or high glucose (22.4 mM) medium, with or without testosterone (0, 1, 10, 100 nM), for 24 hours. HUVEC were trypsinized, resuspended, and then incubated with platelet rich plasma from healthy male donors with ratio 1:10 4 for 3 minutes. Platelet aggregation measured by turbidimetry methode. This study showed that testosterone did not significantly influence platelet aggregation through endothelial cells in normoglucose (p = 0.144) or high glucose (p = 0.916) medium. There was no main effect of testosterone (p = 0.73) as well as no interaction between testosterone and glucose (p = 0.69), but there was a main effect of glucose (p = 0.004), to platelet aggregation through endothelial cells. In conclusion, high glucose, but not testosterone, inhibits platelet aggregation mediated by endothelial cells.

Different Effects of Testosterone to the Expression of Endothelial COX-2 in Normal and High Glucose Environment

“…Primary HUVEC was successfully performed using enzymatic disaggregation method. The morphological cobblestone of the confluence cells and the expression of von Willebrand factor on endothelial cell membrane have been reported in the researcher's previous reports [13][14].…”

“…Any changes in terms of mechanic (pressure) or chemical (including glucose level) in the blood will exert influence to EC. For example, it was reported that high glucose medium depresses the capacity of EC to prevent platelet aggregation [13]. Regarding the influence of high glucose environment to the expression of endothelial COX-2, it still opens to be discussed.…”

“…HUVEC was established according to the technique that have been previously described [10][11][12]. The HUVEC protocol used in this study had been previously reported [13][14]. The donors of umbilical cords were healthy delivered mothers with a healthy full-term newborn baby (Apgar score was >10).…”