Long term toxicological studies on the progestin STS 557

Experimental and Clinical Endocrinology
H HoffmannF Robiller

Abstract

The toxicity of 17 alpha-cyanomethyl-17 beta-hydroxy-estra-4, 9-dien-3-one (STS 557) was studied by its oral administration of 0.1, 1.0 or 10.0 mg/kg/day to Wistar rats for six months, and of 0.01, 0.1 or 1.0 mg/kg/day to beagle dogs for six months, respectively. Levonorgestrel at a dose of 1.0 mg/kg/day was used as the standard in the dog study. With respect to the progestational activity of the compound the main target organs were the hypophysis, the reproductive organs and the adrenals. Mammary hyperplasia was observed in dogs treated with STS 557 or levonorgestrel at the dose of 1.0 mg/kg/day, but in no case mammary nodules could be detected. At the dose of 1.0 mg/kg/day STS 557 and levonorgestrel were found to increase the plasma insulin response to i.v. glucose in bitches, but neither the mean blood glucose levels nor the glucose utilization were affected. Moreover, during administration of both steroids to dogs temporary changes in serum concentrations of triglycerides and total cholesterol were noted. The results obtained in rats and dogs from functional and morphological investigations did not reveal any toxic side effects of STS 557 on the liver, the kidneys, the bone marrow or on blood coagulation. The effects on the...Continue Reading

Related Concepts

Related Feeds

Blood Clotting Disorders

Thrombophilia includes conditions with increased tendency for excessive blood clotting. Blood clotting occurs when the body has insufficient amounts of specialized proteins that make blood clot and stop bleeding. Here is the latest research on blood clotting disorders.