The reproducibility within the laboratory of findings in a three month toxicity study in the rat

Abstract

A three month rat toxicity study was conducted twice with the same compound in the same laboratory. The studies were conducted according to internationally recognized guidelines for subchronic toxicity studies and followed essentially identical protocols (a control group and three dose groups, 10 rats/sex/ group). The compound was administered subcutaneously once daily for three months. Body weight and food and water intake were measured once weekly. Blood samples for hematology and blood chemistry were taken during the week before termination of dosing. Body weight gain and food and water intake were increased in both studies. For great many hematological and blood chemical parameters there was a dosedependent statistically significant increase or decrease in one or both sexes. Some changes attained only the level of significance in one study whereas there was a tendency of a similar change in the other study. Only a few deviations (no or opposit change in one study) were seen between the two studies. Altogether there seemed to be a good correspondance between the findings in the two studies and the variations seen would probably not influence the safety evaluation made from any of the studies.