Effects of oral nicotine on rat liver stereology/Efectos de la nicotina oral en la estereologia del higado de rata

Nicotine is the more abundant component in cigarette smoke. Because nicotine is first metabolized in the liver, our aim was to investigate the effects of nicotine on this organ by biochemical and stereological methods. Male Wistar rats were treated with oral nicotine (ON) diluted in drinking water during 32 days. The control group was treated with drinking water in the same period. Rats were sacrificed 24 hours after last day, the blood was collected and the liver was removed. Lipidogram was performed by enzymatic method and collagen fibers, fat globules and hepatocytes were count in the liver by stereological methods. We observed in control group preserved hepatocytes, with no presence of inflammatory cells. However in the ON group was possible to observe varied size of hepatocytes with cloudy cellular limits and histoarchitecture loss. Capillaries were fully of red blood cells. We observed also an increase of fat globules with small size. We observed in leucogram a reduction of leukocytes number (lymphocytes, neutrophils and monocytes) in the ON group in comparison to control group. The lipidogram showed an increase of triglycerides and total cholesterol for ON group when compared to control group. Moreover, a reduction of HDL- cholesterol was observed in ON group when compared to control group. Numerical density of hepatocytes was lesser in ON group when compared to control group. We suggest harmful effects of oral nicotine in liver induced by toxic mechanism with reduction of hepatocytes number and disturbance in lipid metabolism. KEY WORDS: Nicotine; Rat; Liver; Stereology. La nicotina es el componente mas abundante en el humo del cigarrillo. Primero porque la nicotina es metabolizada en el higado, nuestro objetivo fue investigar los efectos de la nicotina sobre este organo por metodos bioquimicos y estereologicos. Hombre rata Wistar fueron tratados con la nicotina oral (NO) diluida en el agua potable durante 32 dias. El grupo control fue tratado con agua potable en el mismo periodo. Las ratas se sacrificaron 24 horas despues del ultimo dia, se recogio la sangre y el higado fue retirado. Lipidogram se realizo por el metodo enzimatico y fibras de colageno, grasa y hepatocitos se cuentan en el higado mediante metodos estereologicos. Hemos observado en el grupo control hepatocitos conservados, sin presencia de celulas inflamatorias. Sin embargo en el grupo ON fue posible observar variado tamano de hepatocitos con nubes y claros limites celulares y histoa