The following abstract presents results of a study conducted by a contract laboratory for the National Toxicology Program. The findings have not been peer reviewed and were not evaluated in accordance with the levels of evidence criteria established by NTP in March 2009. The findings and conclusions for this study should not be construed to represent the views of the NTP or the U.S. Government.
Cyclosporin A is a potent immunosuppressive drug used to maintain organ transplants and in the treatment of autoimmune diseases. The National Toxicology Program requested that a dose range-finding study be performed in order to determine doses that could be used in a long term carcinogenesis study in a transgenic animal. These studies were conducted in female C57BL/6 mice. The animals were treated with Cyclosporine A for 6 alternating days over a 12-day period by oral gavage. CSA was prepared each dosing day in corn oil. The in-life phase of these studies was carried out between 18, September 1995 and 29, September 1995.
In this study, body weights were not decreased and the only organ weight to show a change was the liver which was increased by as much as 16%. Cyclosporine A produced a biphasic response in the antibody-forming cell response to the T-dependent antigen sheep erythrocytes. At a dose of 10 mg/kg there was a 60% enhanced response, while at the 100 mg/kg dose a 60% reduction in the immune response was seen.