The Factors Affecting the Reference Data of the Total Protein, Glucose, Cholesterol, and Urea Nitrogen in Rats

Abstract

We researched the factors affecting the historical data regarding total protein, glucose, cholesterol, and urea nitrogen from rats used as negative controls in non-clinical toxicity studies. The data were provided by nine laboratories, which covered a study population of approximately 5,000 rats. As for the difference in the food contents (crude protein, crude fat), it confirmed that it influenced total protein, cholesterol, and urea nitrogen in the blood. Furthermore, as for these influences, it was suggested that the influence increased by long-term breeding. Moreover, it was confirmed that glucose and urea nitrogen decreased by fasting before blood collection. There was a difference in the response of total protein between the standard material and rat specimens at the time of measurement, which influenced the measurement value. Therefore, data regarding the areas of total protein, glucose, cholesterol, and urea nitrogen should be collected with special attention being paid to both the animal's feed content and its fasting/feeding conditions. Furthermore, once the standard rat material is marketed, comprehensive gathering of total protein data is expected.