Billie P. Wagner

Some aspects of the development, biology and biochemistry of rat hepatomas of different growth rate

Summary The results of studies on TP induction, catalase activities, growth studies, and ethionine injections confirm the accumulated evidence from many laboratories that individual transplantable hepatomas, even of the “minimal deviation” type, show wide variation in their enzyme activities, even when the original tumors are induced by the same chemical and under as similar experimental conditions as can be provided. Transplantable hepatomas of widely differing biological and biochemical characteristics have also been produced in different lobes of the same liver of the primary host. The induction of transplantable hepatomas of the “minimal deviation” type has been accomplished by several chemical carcinogens. In case of N-2-fluorenylphthalmic acid, tumors have been induced in rats of both sexes in two entirely separate experiments. Therefore, it is concluded that the first “minimal deviation” hepatoma observed, 5123, is not unique.

Thyroxine depression of mouse thyroid iodide trap activity.

Summary Chronic treatment with thyroxine was no more effective than hypophysectomy in depressing the thyroid iodide trap. TSH had some stimulating effect on the activity of the thyroid iodide trap. The combination of TSH and PTU caused a greater response, but insufficient to serve as an assay technic for thyrotropin.