RESUMEN
In the present study we propose a standardization of the method for the induction of fibrosis of the liver in rats by weekly administration of CCl4 by the intragastric route. The present method is a variation of that described by Proctor and Chatamra. The initial CCl4 dose is 0.04 ml (X dose) but the subsequent doses are calibrated using a 5% variation in animal weight as a reference point. For a weight gain of 5% or more, the successive doses are progressively increased by 50 to 150% (1.5X, 2X, 2.5X). When there is no variation in weight or loss in less than 5%, the previous dose is maintained. For a weight loss of more than 5%, the CCl4 dose is decreased by 50%. Consistent fibrosis if obtained as early as during the 8th week. Collagen content increases progressively from the 8th to the 12th week, reaching on average a level eight-fold higher than that observed in the control.