BACKGROUND: Smoking during pregnancy is detrimental to the intrauterine growth of the child. As in pregnancy, its effects on lactation and breast-fed child is the sum of adverse infant development. AIM: To analyze the effects of nicotine on the proliferation of myofibroblasts and of blood vessels, on the abdominal scar of suckling rats born of mothers that received nicotine, during pregnancy and lactation. METHODS: Pregnant Wistar rats were randomly divided into two groups, the nicotine group (NG), in which nicotine was administered subcutaneous at a dose of 2 mg/kg/day, during pregnancy and lactation, and the control group (CG), that received subcutaneous isovolumetric saline solution at 0,9%, in the same period of time. Sixty baby rats, divided into two groups, were weaned at 21 days and a transverse laparotomy was performed. Each group was divided into two subgroups, each one containing 15 baby rats, in accordance with the date when the surgical scar was analyzed: on the 7th post-operative day, control subgroup C7 and nicotine subgroup N7, or on the 21st post-operative day, control subgroup C21 and nicotine subgroup N21. The surgical scar in the healing area was evaluated by immunohistochemistry study for identification of myofibroblasts and of blood vessels. The statistical analysis was based on the Anova model, at a significance level of 5%. RESULTS: The subgroup N7 presented lower number of myofibroblasts (9,93 ± 3,06 vs. 21,87 ± 9,07, p=0,007) and lower number of blood vessels (8,33 ± 4,43 vs. 13,4 ± 5,33, p=0,031) when compared to C7. The subgroup N21 presented no significant difference on the number of myofibroblasts (7,47 ± 3,96 vs. 12,00 ± 7,21, p=0,121) and on the number of blood vessels (9,47 ± 2,42 vs. 12,93 ± 4,35, p=0,090) when compared to C21. CONCLUSION: Adverse effect of nicotine, administrated in pregnancy and lactation period, was observed on the proliferation of myofibroblasts and of blood vessels on the abdominal wall wound healing of suckling rats.
Wound healing; Laparotomy; Nicotine; Immunohistochemistry
