Abstract
It is quite difficult to determine the reference clinical chemistry values in non-clinical toxicity studies in the laboratory rat. There are 3 reasons for this: 1) the blood volume of rats is less than that of humans, and sampling induces considerable stress in rats, 2) the use of human reagents for clinical chemistry in rats sometimes fails to provide the necessary specificity, and 3) when statistically significant differences are evident in the clinical parameters evaluated in toxicity studies, the lack of correlation with histopathological evaluation makes the findings meaningless in many cases. Therefore, a clinical chemistry reference data in rats was established based on the values in untreated or negative control animals (approx. 5,000rats) in toxicity studies which have been conducted since 1994 at 9 member laboratories of the Committee on Animal Clinical Chemistry, Japan Society of Clinical Chemistry. Measurement conditions were confirmed and factors which may affect the determination of standard values were investigated. In this paper, the method of database preparation and the outline are presented, and technical factors including artifacts which may affect the determination of reference values are discussed based on the literature. Subsequently, the standard values of individual parameters are discussed by assigned authors. Also, the relationship between albumin and reagents is reported separately.
