RESUMEN
It was previously demonstrated that it is possible to increase the size of the intact liver of rats, contray to the biological determination that ties liver size to animal size bay intraperitoneal (portal) administration of exogenous hepatotrophic factors (a solution containing glucose, amino acids, insulin, glucagon, vitamins, and electrolytes) which qualitatively mimie substances and hormones normally present in splanchnic blood (PARRA et al.). In the present investigation, we studied the possible action of fat (LipofundinR), human milk growth factors, co-factors (folic acid, vitamin B12 and zinc), and thyroid hormone (T3 on the regenerative stimulus when added to the above solution. T3 was found to be an important factor which increased liver mass when compared to the basic solution (67.54 por cento) versus 36.07 por cento). Although these values were not compared statistically due to the small number of surviving animals, they are important as guidelines for future research about new compositions of hepatotrophic solutions that will maintain or improve the level of stimulation obtained thus far, with a possible reduction in animal mortality