Effects Of Topical Insulin Application On Wound Healing And Its Mechanism Of Diabetes Rats

In recent years ,more attention has increasinly been paid to the effect of insulin and glycemia regulation on diabetes wounds, studies indicate that insulin ,one of the most important anabolism hormone , can promote the synthesis of the hephormone and transportation of the glucose ,and increase the synthesis of protein and storage of the lipid in adipocyte. The exogenous insulin is helpful to rectify negative nitrogen balance and promotes the formation of blood vessel. And insulin can also promote the capacity of antiinflammatory and cell multiplication or differentiation etc .Wound healing is a series of recovery activity that the organism maintain the homeostasis and the recovery of superficial succession and integrity depending on its own regeneration capacity . wound recovery is a orderly,step-by-step procedure.it includes a series of stage such as : inflammation; Cellular proliferation; apposition ; tissue re-establishment.. a lot of complicated elements are involve into these stages that including wound coagulation; inflammation; granulation tissue formation ; epithelialization ; blood vessel regeneration ; Neovascularity formation ;Collogen synthesis ;wound contraction. Two important parameters of wound healing are epithelization and vascularization . diabetes results in the periphery arteries scleratheroma that cause extensive small vessels endotheliosis and capillary basement membrane thickening ,which cause the vasomotion dysfunction and reduction of blood flow .Diabetic Chronic ulcer of skin has close relationship with anoxaemia and ischemic condition of tissues. late healed wound of diabetes is a puzzle to us for a long time, three key points that influence the wound healing of diabetes are vessel element ,nerve element and infection element. It is found that Clinical local insulin application can improve the wound healing with little influence on blood glucose level. Inflammatory reaction is a very important part of wound healing . Insulin participates the regulation of many links . decrease the pre-inflammatory cell factor siginficantly ; prevent excessive inflammatory reaction ; restrain the protein degradation of heterophil granulocyte in peripheral blood and spleen. Increase the capacities of celluar tendency and phagocytosis ,and improve the immune level. In theory , local insulin application can cause histiocyte to absorb or diffuse insulin initiatively, to regulate the utilization of carbohydrate and energy production and to promote the amino acids entering the cell to synthesize protein . More importantly, it can speed up the local vascularization and fibroblastic growth and collogen composition. The dosage of insulin and its administration route are discussed at present . In order to identify the mechanism of local insulin usage and its clilical safety , we design this experiment . This study was to investigate the effects of topical application of insulin on glycometabolism ,wound healing,bacterium growth,cell proliferation. we apply the indexes of macroscopic and microcosmic scope . Macroscopic indexes include healing time,healing rate and FB cell numbers and local inflammation reaction . Microcosmic indexes include Angiogenesis and collagen synthesis, endogenous EGF ,CD34,etc to reveal the mechanism and safety of insulin so as to supply the sound theoretical basis for the topical use of insulin on the wound. We get the results that in point of the effect of insulin on the blood glucose,it is obvious safer in small dosage group than that of the large dosage group.topical application of insulin on wound can promote decrease the local inflammation reaction ,promote the expression of CD34,VEGF and neovascularization, increase of HYP, All of anaerobic bacterium and aerobic bacteria on the wound decreased ,especially the anaerobic bacterium. Cell proliferation circle is ahead of schedule ,nerve regeneration also advanced. local infiltration is a better choice for use of insulin .Conclusion : blood vessel , nerve degeneration, infection are three key points for Diabetes gangrene . The micro-organism features of it is the combined infection of anaerobian and aerobe . The results of our research strongly support that the subcutaneous injection of 0.1U insulin into the wounds can speed up the neovascularization and nerve regeneration of the wound and the wound healing, relieve the wound infection. and there is little influence on blood glucose, the topical application of small dosage insulin is effective and safe ,this study can supply the theoretical basis for the clinical application.