Rev. Col. Bras. Cir. 2016; 43(2):
INTRODUCTION
With the growing concern and the global debate on the harmful effects of tobacco on the human body, much attention has been directed to the adverse consequences of smoking. The direct and indirect costs related to diseases linked to smoking consume considerable resources for health in our country. Neoplasms, cardiovascular and respiratory diseases associated with smoking are well documented. However, less attention has been paid to surgical complications related to smoking [1][2][3][4] . Although tobacco products are consumed for hundreds of years, only in the twentieth century there was a sharp increase in consumption, the cigarette being the most important form of use. Its toxic smoke has more than 5,000 elements, of which nicotine is the primary vasoactive component, considered to cause the smoker's addiction, as it strengthens and enhances the desire to smoke 3,5,6 . The so-called granulation tissue, essential for a healthy scar development, comes at the beginning of the second stage of healing, called proliferative, being mainly composed of newly formed blood vessels (angiogenesis) and modified fibroblasts, called myofibroblasts4. While angiogenesis provides the blood supply suitable for the high level of metabolic activity that the healing process requires, myofibroblasts, through their contractile force, approach the damaged tissue edges 7 . In 1977, Mosely and Finseth 8 drew attention in a pioneering way to the undesirable effects of nicotine on tissue healing. Since then, several clinical and experimental studies have tried to explain these effects, demonstrating that this substance causes deficiencies in several factors involved in the healing process, in areas as diverse as Plastic Surgery and Orthopedics 9 .
A B S T R A C TObjective: to know the effect of nicotine on angiogenesis and myofibroblast formation in anastomoses of the small bowel of rats. Methods: we randomly divided 60 Wistar rats into the groups Nicotine (N) and control (C), according to the proposed treatment. Each group was subdivided into three subgroups according to the time interval used for the evaluation (7, 14 or 28 days). The N group with 30 animals received nicotine subcutaneously at a dose of 2mg/kg body weight, diluted in 0.3ml of 0.9% saline, twice daily for 28 days prior to the operation, and for more 7, 14 or 28 days, depending on the subgroup. The C group (also 30 animals) received only saline on the same conditions and time intervals. After 28 days we carried out an end-to-end anastomosis 10cm distal to the duodenojejunal flexure in each rat. After 7, 14 or 28 days after surgery, we euthanized ten animals of each group, sent specimens of the anastomosis areas, 1cm proximal to 1cm distal, to counting of blood vessels and myofibroblasts through immunohistochemical staining by the application of monoclonal anti-factor VIII antibodies and anti-smooth muscle alpha-actin. Results: the administration of nicotine led to the decrease in the number of blood vessels measured on the 28...
