title: [Effects of nerve growth factor mixed insulin on angiogenesis of burn wounds and expressions of Bcl-2 and Bax in diabetic rats].
abstract: OBJECTIVE
  To explore the possible mechanism of nerve growth factor (NGF) mixed insulin on the angiogenesis of burn wounds and the effect on the expressions of Bcl-2 and Bax in diabetic rats.
  
  
  METHODS
  A total of 75 SPF male Wistar rats, weighing 200-220 g, were selected randomly and divided into nomal control (group A, n = 15), the rats with diabetic control (group B, n = 15), insulin treatment (group C, n = 15), NGF treatment (group D, n = 15), NGF and insulin treatment (group E, n = 15) groups. In groups B, C, D, and E, streptozotocin was given by intraperitoneal injection at dose of 10 mg/kg on the 1st day and 50 mg/kg on the 3rd day to prepare the diabetic rat models. In group A, citric acid buffer at the same dose was given. After 1 month of diabetic models, second degree scald was made on the back of the rats, and then wounds were treated with 3-layer normal saline gauze in groups A and B, with 3-layer gauze containing 5 U Novolin 30R and subcutaneous injection of Novolin 30R (4-6 U/kg) everyday in group C, with 3-layer gauze containing 5 mL NGF (25 U/mL) in group D, and with a combination of groups C and D in group E. At 7, 11, 15, and 21 days, the wound healing rate was calculated; at 3, 7, 11, 15, and 21 days, the expressions of Bcl-2, Bax, and CD34 were determined and the microvascular density was measured by immunohistochemistry staining.
  
  
  RESULTS
  All rats survived till experiment was finished. The area of wounds became smaller gradually with time. Group E was better than other groups in the wound healing rate (P < 0.05), the skin keratosis, the hair growth, and the granulation tissue and collagen fibers growth. With time, the expressions of CD34 and Bcl-2 increased gradually, reached the peak at 15 days and decreased at 21 days; the expression was stronger in group E than in other groups (P < 0.05). At 3 days, Bax did not express; at 7 days, Bax began to express in new vascular endothelial cells and the expression increased gradually with time; the expression was weaker in group E than in other groups (P < 0.05).
  
  
  CONCLUSIONS
  A combination of NGF and insulin local application can enhance the angiogenesis of the burn wound in diabetic rats and accelerate wound healing by increasing the expression of Bcl-2 and decreasing the expression of Bax and restraining apoptosis of the wounds vascular endothelial cells of diabetic rats.
authors.affiliation: Department of Burns and Plastic Surgery, Gansu Provincial People's Hospital, the First Clinical Medical College of Lanzhou University, Lanzhou, Gansu, 730000, P.R.China.
authors.forename: Jibei
authors.initials: J
authors.lastname: Zhang
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Xue
authors.forename: Peilin
authors.initials: P
authors.lastname: Xie
authors.forename: Fei
authors.initials: F
authors.lastname: Chang
mesh_terms: D000818:Animals; D002056:Burns / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental; D042783:Endothelial Cells / Q000378:metabolism; D007328:Insulin / Q000627:therapeutic use*; D008297:Male; D018919:Neovascularization, Physiologic / Q000187:drug effects; D020932:Nerve Growth Factor / Q000627:therapeutic use*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014945:Wound Healing; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
chemical_list: C494828:Bax protein, rat; D007328:Insulin; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D020932:Nerve Growth Factor