SUMMARY: A total of 24 female rats, aged 4 months and weighing approximately 250 g and they given a solution of 40 % alcohol dissolved in water, leading to alcoholic multivesicular steatosis and 12 of rats was given and infrared laser with dose of 8 J/cm2 during 15 d. The rats were then killed and samples of steatosis and stimulated and were taken and processed for examination by transmission electron microscope. Transmission electron microscope microphotographs steatotic hepatocytes and stimulated steatotic were obtained with final magnification of 9,500 X. They were subjected to morphometric studies to determine the number of nuclear pores and volumetric fractions and areas the following components: cellular and nuclear area, volumetric fractions of nucleus, nucleolus, eu and heterochromatin, nucleocytoplamic ratio of each cell type was determined. Analysis of the results between alcoholic hepatocytes and stimulate alcoholic shows that noticeable differences exist in all the cell components quantified. It is concluded that the effects of the stimuli of laser infrared provoke in the hepatocytes, a drastic transformation of their ultrastructure and morphology. This finally leads to functional variations, representing the effects produced by this stimulate in the hepatocytes.

KEY WORDS: Steatosis; Laser; Morphometry; Hepatocytes.