OBJECTIVE: To explore the molecular mechanisms involved in the increased collagen synthesis by platelet-derived wound healing factors (PDWHF) during wound healing in alloxan-induced diabetic rats. METHODS: Thirty-three male SD rats were divided into two groups, the normal (n = 9) (group A) and the diabetic group (n = 24). Two pieces of full-thickness skin with diameter of 1.8 cm were removed from the dorsal site of diabetic rats. PDWHF (100 micrograms/wound) was topically applied to one side of the diabetic wounds (group B) on the operation day and then once a day in the next successive 6 days. Meanwhile, bovine serum albumin (100 micrograms/wound) was applied to the other side of diabetic wound as control group (group C) in the same way. Levels of transforming growth factor-beta 1 (TGF-beta 1) and procollagen I mRNA in wound tissue were inspected by dot blotting. RESULTS: TGF-beta 1 mRNA levels in group B were 4 folds and 5.6 folds compared with those in group C after 5 and 7 days (P lt; 0.01), however, still significantly lower than those of group A (P lt; 0.05). There was no significance difference among three groups on the 10th day after wounding. The levels for procollagen I mRNA in group B amounted to 2.1, 1.8 and 2.3 folds of those in group C after 5, 7, and 10 days (P lt; 0.01), respectively. Compared with those in the group A, procollagen I mRNA levels in the group B were significantly lower after 5 and 7 days (P lt; 0.05), and no significant difference was observed between group B and A after 10 days. CONCLUSION: One important way for PDWHF to enhance the collagen synthesis in diabetic wound healing is to increase the gene expression of endogenous TGF-beta 1.
OBJECTIVE The effect of platelet-derived wound healing factor (PDWHF) on wound healing in diabetic rats was studied. METHODS Forty-four male SD rats were randomly divided into 2 groups. Thirty-two rats of experimental group accepted intraperitoneal injection of alloxan (1.5 mg/10 g body weight). Within one or two days after injection, while the blood sugar of the rats was higher than 180 mg/dl, the animal model of diabetic rat should have been established. Then a dorsal incision was given to every rat. After the addition of PDWHF (the experimental group) or bovine albumin (the control group), the incision was sutured up. Seven, ten and fourteen days after operation, the breaking strength of the wound was measured. On another hand, specimen from the wound was taken for the culture of fibroblasts. When the cultured fibroblasts have been incubated with 10% PDWHF for 4, 8 and 12 hours, the procollagen I (alpha 1) mRNA levels were examined respectively, and compared with those of control. RESULTS Significant difference in wound breaking strength had been observed between PDWHF-treated incisions and the control on 7, 10 and 14 days after wounding (P lt; 0.01). Experiment in vitro demonstrated that the procollagen I (alpha 1) mRNA levels in wound fibroblasts incubated with 10% PDWHF for 4, 8 and 12 hours were 0.9, 3.7 and 2.2 folds higher than those in fibroblasts in control. CONCLUSION It was suggested that direct stimulation of procollagen I (alpha 1) gene expression was one of the ways that PDWHF played its role in accelerating wound healing.
OBJECTIVE To investigate clinical effects and possible mechanisms of various growth factors on impaired healing ulcers of patients with diabetic disease. METHODS Seventy-eight patients were divided into three groups; saline control, epidermal growth factor(EGF) experimental group, and platelet-derived wound healing factor (PDWHF) experimental group. General healing conditions, wound closing index, healing rates and histological changes of the patient’s ulcer wound were observed during 1-8 weeks after treatment. RESULTS The wound closing index and healing rate of ulcers were significantly increased in the EGF and PDWHF experimental groups compared with the control group, while the angiogenesis, fibroblast hyperplasia, and collagen deposit were more obvious in EGF and PDWHF experimental groups than that of control group. The promoting effects on wound healing in PDWHF experimental group were better than in EGF group. CONCLUSION It suggests that local application of certain growth factor alone or various growth factors together is an effective method to improve the condition of impaired healing of diabetic ulcers.