Results

The purpose of this study was to determine, from a range of doses, which would evoke limiting pharmacologic response or lesions. This information must be known before starting a carcinogenicity study, in which untoward effects, incompatible with long term survival of the animals, must be avoided. Procedure Ten rats per sex group were injected daily in the thigh muscle with the following doses of gold sodium thiomalate: 192 (97), 96 (48.5), 48 (24.2). 24 (12.l), 12 (6.1), 6 (3). or 3 (1.5) mg/kg/day. In order to achieve the 3 highest doses, the drug was injected undiluted, i.e., as a 5 % solution. With the highest dose, a mature rat weighing 0.4 kg received about 1.5 ml at each injection. For the 4 lower dose groups the commercial material was diluted with water to make a 2.5 % solution. The control group was injected with sterile water. The local effects of injection and a detailed description of the renal lesions are reported separately from the systemic toxicity