The effects of feeding an elemental chemical diet to mature rats: toxicologic and pathologic studies

An 8-week study was conducted in mature Sprague-Dawley rats to determine the effect of feeding a liquid elemental chemical diet as the sole source of nutrition. Periodic studies showed that blood and urine were normal except for a slight decrease in urine specific gravity, blood urea nitrogen, and hemoglobin-hematocrit values in some of the animals. Prolonged prothrombin times and bleeding, observed in some animals, were ascribed to a questionable deficiency of vitamin K. Histopathologic examinations of the tissues showed no abnormalities except for the indication, in some animals, that fatty metamorphic changes had occurred in the liver. Apparently these changes resulted from a lipotropic factor deficiency that was reversed by the addition of choline to the diet. In all other respects the diet appeared to be well tolerated.