The effects of overnight fasting, feeding, or sucrose supplementation prior to necropsy in rats

This study was designed to investigate the acute effects on routine hematology, serum biochemistry, gastrointestinal contents and weight, and liver weight and morphology due to overnight sucrose feeding of rats prior to necropsy. Groups of rats (five males and five females/group) were fasted overnight, fed chow, or fed sucrose and were euthanized approximately 17 h later. At necropsy, blood was obtained for hematology and serum biochemistry profiling, and the livers and gastrointestinal tracts were weighed and examined. The livers also were evaluated microscopically. The blood glucose and urea nitrogen concentrations and liver weights of animals fed sucrose differed significantly from those of the other groups. Alterations were more striking in males than females. Marked histological changes were present in livers from animals fed sucrose prior to necropsy compared with fasted or chow-fed animals, and these changes were attributed to increased glycogen deposition in the sucrose-fed animals. Because of alterations in hepatic structure and function, we cannot recommend the practice of feeding sucrose to rats prior to necropsy for toxicology studies or any studies examining hepatic function.