title: Acute and subchronic toxicology of LY-195115 in rats and dogs.
abstract: LY-195115 is a new (investigational) inotropic agent. When given orally to either young adult rats or mice, single doses of 2500 or 5000 mg/kg were tolerated with minimal lethality. Clinical signs included muscle weakness, hypoactivity, and evidence of hemorrhage. Dogs and monkeys survived a single oral dose of 10 and 5 mg/kg, respectively; however, there was sinus tachycardia for 6-8 h post dose in both species. Rats (20/sex/group) were fed diets containing LY-195115 in concentrations of 0, 0.005, 0.025, or 0.1% for 3 months. The average daily intake of the compound was approximately 0, 3.5, 17, or 70 mg/kg in both sexes. Deaths occurred only in the high-dose group. Body weight gain, food consumption, and efficiency of food utilization were significantly reduced in males in the 0.1% dose group and animals of both sexes in this group had changes in hematology, clinical chemistry, and urinalysis parameters indicative of renal damage. Crystals containing LY-195115 were present in the urine of animals from the 0.025% and 0.1% treatment groups. Secondary hydronephrosis due to kidney stone formation was observed on gross and microscopic pathologic evaluation in the males of the 0.025% group and animals of both sexes in the 0.1% group. In addition, periarteritis was present in the adventitia and muscularis of small and medium-sized arteries in the pancreas, lymph node, kidney, and stomach of some animals in all LY-195115 treatment groups. No overt signs of toxicity were produced in beagle dogs (4/sex/group) given daily oral doses of 0.03, 0.12, or 0.5 mg/kg of LY-195115 for 3 months. The only adverse effect was the occurrence of focal subendocardial fibroplasia in the heart in 2 high-dose male dogs. Thus, subchronic exposure of rats to doses of LY-195115 as high as 70 mg/kg produced minimal mortality, renal toxicity, and mild, limited vascular changes, while dogs tolerated doses up to 0.5 mg/kg with no evidence of any effect of treatment except minimal histological changes in the heart consequent to the expected cardiotonic action of the compound.
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001806:Blood Urea Nitrogen; D001835:Body Weight / Q000187:drug effects; D004285:Dogs; D005260:Female; D006321:Heart / Q000187:drug effects; D007211:Indoles / Q000097:blood / Q000633:toxicity*; D007668:Kidney / Q000187:drug effects; D008253:Macaca mulatta; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D000078183:Oxindoles; D011724:Pyridazines / Q000097:blood / Q000633:toxicity*; D051381:Rats; D011916:Rats, Inbred F344; D013045:Species Specificity
chemical_list: D007211:Indoles; D000078183:Oxindoles; D011724:Pyridazines; C050325:indolidan