Co- localization of Flt1 and tryptase of mast cells in skin wound of rats with type I diabetes: Initial studies.

Random skin flap (RSF) is commonly used in plastic and reconstructive surgery, but its distal part often occurs ischemia. Type 1 Diabetes mellitus (T1DM), may be detrimental for flap survival by provide sever ischemia. We sought to determine the influence of DM on the relation between mast cells and angiogenesis by examining tryptase and Fms-like tyrosine kinase 1 (Flt-1), a well-known vascular endothelial growth factor receptor (VEGFR-1), in the surviving areas of RSF in healthy and diabetic rats. 16 male rats divided into healthy and diabetic groups. T1DM was created in the diabetic rats, followed by generation of a RSF in both the control and diabetic rat. On day 7, the surviving areas of each RSF were recorded. Then animals were euthanized, and numbers of vessels, mast cells and co-localization of mast cell tryptase and Flt-1 were analyzed. T1DM decreased survival areas in the RSF compared to the healthy rats, with higher percentage of intact and degranulated mast cells. T1DM elevated the expression percentage of tryptase and VEGFR-1in the proximal and middle areas of the survival parts of the RSF in most diabetic rats. Generally, our results showed that mast cell degranulation might have a positive correlation with VEGFR-1 and in this current model of ischemic tissue in diabetic rats, this finding could lead to poor angiogenesis and weakened blood vessel function, which might result in decreased RSF survival. Additional molecular mechanisms that pertain to the effects of DM on ischemic tissues healing such as this RSF model should be determined by further investigations.