Toxicology and Carcinogenesis Studies of Furosemide (CAS No. 54-31-9) in F344/N Rats and B6C3F1 Mice (Feed Studies).
- 1 May 1989
- journal article
- Vol. 356, 1-190
Abstract
Furosemide is a diuretic used in human and veterinary medicine. Toxicology and carcinogenesis studies were conducted by feeding diets containing furosemide (99% pure, USP grade) to groups of F344/N rats and B6C3F1 mice of each sex for 14 days, 13 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, mouse L5178Y lymphoma cells, and Chinese hamster ovary (CHO) cells. Fourteen-Day and Thirteen-Week Studies: Dietary concentrations of furosemide used in the 14-day studies for rats and mice ranged up to 46,000 ppm. Two of five male and 3/5 female rats that received 46,000 ppm furosemide died before the end of the studies. Rats that received 15,300 or 46,000 ppm lost weight over the course of the studies. The final mean body weights of rats that received 1,700 or 5,100 ppm were 12% or 23% lower than that of controls for males and 8% or 16% lower for females. Nephrosis was dose related in rats. All five male and 1/5 female mice that received 46,000 ppm furosemide died before the end of the 14-day studies. Male mice that received 15,300 ppm and female mice that received 46,000 ppm lost weight. The final mean body weights of male mice that received 1,700 or 5,100 ppm were 16% or 14% lower than that of controls. The final mean body weight of females that received 15,300 ppm was 13% lower than that of controls. Slight dilatation of the renal cortical tubules and/or nephrosis were dose related in mice. Dietary concentrations of furosemide used in the 13-week studies were 0 and 625-10,000 ppm for male rats and 0 and 938-15,000 ppm for female rats and male mice. Concentrations for female mice were 0 and 1,250-20,000 ppm. None of the rats died before the end of the studies. The final mean body weights of male rats that received 2,500, 5,000, or 10,000 ppm furosemide were 11%, 22%, or 44% lower than that of controls. The final mean body weights of female rats that received 3,750, 7,500, or 15,000 ppm were 18%, 26%, or 35% lower than that of controls. Minimal-to-mild nephrosis occurred in the two highest dose groups of male and female rats. Mineralization of minimal to mild severity was observed at the renal corticomedullary junction in dosed male rats receiving 625 ppm or more; the severity and incidence of the mineralization increased with increased dose. No compound-related deaths occurred in mice. The final mean body weights of male mice that received 3,750, 7,500, or 15,000 were 12%, 22%, or 17% lower than that of controls. Final mean body weights of dosed and control female mice were comparable. Compound-related lesions in mice induced minimal-to-mild nephrosis. Because of the lower body weights and the kidney lesions in the 13-week studies, doses selected for the 2-year studies were 0, 350, or 700 ppm furosemide in the diet for groups of 50 F344/N rats of each sex. Groups of 50 B6C3F1 mice of each sex were fed diets containing 0, 700, or 1,400 ppm furosemide for 104 weeks. Body Weight and Survival in the Two-Year Studies: Mean body weights of dosed and control rats were comparable throughout the studies. No significant differences in survival were observed between any groups of rats of either sex (final survival--male: control, 17/50; low dose, 17/50; high dose, 20/50; female: 35/50; 31/50; 34/50). The final survival of all groups of male rats was low, reflecting the large number of moribund animals killed after week 91. Survival at week 90 was 35/50, 28/50, and 34/50. Mean body weights of high dose male mice were up to 17% lower than those of controls, and mean body weights of low dose male mice were about 5%-10% lower than those of controls after week 31. Mean body weights of high dose female mice were up to 22% lower than those of controls. Mean body weights of low dose female mice were 5%-13% lower than those of controls after week 82. The survival of the high dose group of female mice was significantly lower than that of controls after week 99 (final survival--male: 31/50; 24/50; 26/50; female: 36/50; 29/50; 18/50). Feed consumption by dosed rats was similar to that by controls. The estimateer week 99 (final survival--male: 31/50; 24/50; 26/50; female: 36/50; 29/50; 18/50). Feed consumption by dosed rats was similar to that by controls. The estimated average amount of furosemide consumed per day was approximately 14-16 or 29-31 mg/kg for low dose or high dose rats. Feed consumption by dosed mice was approximately 5%-7% greater than that by controls. The average amount of furosemide consumed per day was approximately 91-99 or 191-214 mg/kg for low dose or high dose mice. Nonneoplastic and Neoplastic Effects in the Two-Year Studies: Nephropathy occurred at similar incidences in all groups of rats, but the severity was greater in dosed male rats. Tubular cell hyperplasia was observed in 4/50 control, 2/50 low dose, and 4/50 high dose male rats. Tubular cell adenomas of the kidney occurred in 1/50 control, 3/50 low dose, and 1/50 high dose male rats. Tubular cell adenocarcinomas were seen in a fourth low dose male rat and in a second high dose male rat (adenomas or adenocarcinomas, combined: control, 1/50; low dose, 4/50; high dose, 2/50). The historical incidence of renal tubular cell adenomas or adenocarcinomas (combined) in untreated male F344/N rats is 9/1,928 (0.5%), and the highest incidence observed in controls is 3/50. Malignant meningiomas of the brain occurred in 3/50 low dose male rats; none was observed in other groups. The historical incidence of meningiomas in untreated male F344/N rats is 2/1,928 (0.1%). C-Cell adenomas of the thyroid gland in female rats occurred with a positive trend; the incidence in the high dose group was not statistically greater than that in the controls (4/50; 6/50; 11/50). A C-cell carcinoma occurred in another low dose female rat. The incidence of adenomas of the anterior pituitary gland in low dose male rats was marginally greater than that in controls (4/50; 11/50; 8/50). Neither of...This publication has 0 references indexed in Scilit: