PURPOSE: To study the collagen density and the population of fibroblasts in cutaneous injuries in rats under the influence of nicotine. METHODS: The scars of abdominal wounds in rats were analyzed. 2 mg/kg/d of nicotine was administered to the animals in the experiment group and the solution used as a vehicle for the animals in the control group. Treatment was begun seven days prior to surgery and maintained for seven or fourteen days following surgery. The removed scars were prepared for histopathological study. Histological cuts were stained by Sirius Supra red F3BA for collagen analysis and submitted to the examination using the immunohistochemical technique, which enabled us to recognize the population of fibroblasts. RESULTS: No significant difference was found in type I collagen density after seven days (p=0.912), nor after fourteen days (p=0.211). The control group had more type III collagen after seven days (p=0.004), but after fourteen days there was no significant difference (p=0,720). The total quantification of collagen, although higher in the control group, was not significantly so at any time during the study (p=0.103 after seven days and p=0.549 after fourteen days). The average of fibroblasts per field was lower after seven days (p=0.0001) and after fourteen days (p=0.0000). CONCLUSION: Under the conditions of this experiment, nicotine reduced the fibroblast population without modifying collagen density significantly.
Wound Healing; Collagen; Fibroblasts; Nicotine; Tobacco; Rats