Copper status of red deer on the island of Rhum.

The mean (+/- sd) liver copper level of 186 red deer (Cervus elaphus) (87 stags and 99 hinds) on the island of Rhum was 51.26 +/- 44.1 ppm dry matter. The level found in the south-east part of the island was significantly higher than elsewhere in hinds, but not in stags. Levels below 20 ppm dry matter, comparable to those found in cases of enzootic ataxia in deer parks, occurred in 18 stags and 20 hinds. Since enzootic ataxia has never been observed on Rhum, it is deduced that low copper status is not of itself the causal factor in that disease. No significant correlation was found between liver copper levels and stocking rate, age, carcase weight, antler weight, antler specific gravity, hind fertility, natural mortality or transferrin phenotype. It is concluded that above a low but perhaps critical level, the copper status of red deer merely reflects the dietary intake of that element.

Toxicologic and carcinogenic evaluation of Fenvalerate in the B6C3F1 mouse.

Groups of 50 male and 50 female B6C3F1 mice were fed dietary concentrations of 10, 50, 250 or 1250 ppm Fenvalerate for 2 years. Two groups of control mice, 50 per sex per group, received basal diet only. Mortality was increased and body weight was significantly decreased in male and female mice in the 1250 ppm treatment group. Mean body weight of female mice in the 250 ppm group was also generally lower than controls after the 60th week of feeding. Decreased albumin and increased glutamic oxaloacetic transaminase levels in mice fed 1250 ppm Fenvalerate were the only effects observed in the hematology and serum chemistry parameters examined. The only treatment related non-neoplastic pathologic effect observed in the study was multifocal microgranulomata in lymph nodes, liver and spleen of 1250 ppm male mice and 250 and 1250 ppm female mice. Less severe microgranulomatous changes were present in mesenteric lymph nodes of 50 and 250 ppm male mice. No statistically significant differences were observed in either the number or type of neoplasms in mice fed Fenvalerate diets when compared to concurrent controls. Thus, Fenvalerate was found not to be carcinogenic in B6C3F1 mice under the conditions of the test.

Oncogenic evaluation of tetrachlorvinphos in the B6C3F1 mouse.

Groups of 80 male and 80 female B6C3F1 mice were fed diets containing 17.5, 64, 320, 1600, 8000, and 16000 ppm tetrachlorvinphos (TCVP) for up to 103 weeks. Another group of 80 male and 80 female mice were fed TCVP (16000 ppm) that was used in a previous bioassay. One hundred-sixty male and 160 female mice served as the control group. Ten treated and 20 control mice/sex/group were killed at 6, 12, and 18 months. It was estimated that the study maximum-tolerated dose was exceeded by three- and sixfold in the 8000- and 16000-ppm dose groups, respectively. Consequently, these exposures produced excessive cytotoxicity and regenerative changes in the liver and kidneys which were associated with sex-hormonal imbalance and metabolic overload in liver. A significant decrease (15-40%) in body weight was observed in mice fed 8000 and 16000 ppm TCVP. These treated mice did not gain weight during the study. Reduced food consumption and caloric intake throughout the study were probably responsible for the increased survival and the decreased incidence of spontaneous neoplasia in mice fed 8000 and 16000 ppm TCVP. Classification of pathologic lesions observed in these high-dose groups differed among study and consulting pathologists. The consultant and Shell pathologists concluded that the liver and kidney changes were causally related to excessive toxicity which was manifest primarily by hepatocellular hyperplasia and renal tubular adenoma. Study pathologist in accordance with his classification found statistically significant increases in hepatocellular carcinoma, hepatocellular adenoma or carcinoma, and renal tubular carcinoma in male mice fed 16000 ppm TCVP. The incidence of hepatic neoplasms as evaluated by the study pathologist in female mice fed 8000 and 16000 ppm TCVP although statistically significant was of questionable biologic significance when compared with historical female controls. The only statistically significant finding observed by the consulting pathologist was an increased incidence of renal tubular adenoma and renal tubular adenoma or carcinoma in male mice fed 16000 ppm TCVP. Use of results from these high-dose groups is contraindicated due to the many compromising factors affecting mice fed 8000 and 16000 ppm TCVP. TCVP was found not to be oncogenic in B6C3F1 mice at dose levels not exceeding the maximum tolerated dose.