Correlation between size and external temperature of the ISIS 130 tumour after treatment with cytostatic agents.

The reduction in size of the experimental ISIS 130 tumour has been investigated in LOU rats under the influence of increasing doses of cytostatic agents belonging to different classes. External temperatures of tumours as well as rectal temperatures have been measured at the same time, twice daily, during the whole experiment. The greater the decrease in the tumour size after drug administration, the larger was the decrease in external temperature of tumour.

Effect of chemotherapy on tumor temperature in rats.

Two transplanted rat immunocytomas with different degrees of sensitivity to single injection of cyclophosphamide (CY) were used to assess the reliability of recording of the tumoral and rectal temperatures may be useful to evaluate the efficacy of cytostatic drugs against experimental rat tumors. With the highly sensitive tumor (ISIS 130), 25 mg/m2 of CY resulted in a pronounced tumor inhibition (Treated/Control tumors = 28%); with the less sensitive (ISIS 208), a CY dose of 320 mg/m2 was necessary to inhibit tumor growth to the same extent. The more important the decrease in tumor size was, after the administration of the drug, the larger the decrease was in tumoral temperature.

Increase in nuclease activity as a possible means for detecting tumor cell sensitivity to anticancer agents.

Histochemical activity of nucleases was investigated in sensitive and resistant rat tumors at several periods after a single dose of cyclophosphamide and was compared with that in a control group of untreated tumors. Intense increase of nuclease activity(mainly that of acid DNAse) appeared only in the cells of the sensitive tumors at 12 hours, reaching its maximum three days after drug administration. Untreated malignant tumors usually have variable amounts of spontaneous necrosis with high nuclease activity.

A transplantable immunocytoma of the rat as a model for the study of immunoglobulin secretion.

An immunoglobulin secreting tumor appeared spontaneouldy in the LOU/Dec rat strain in an incidence of about 3--5% at age 8-20 months. Attempts to increase the incidence using such things as genetic selection, carcinogens, immunosuppressants, adjuvants, cell-free fumor material, and antigenic stimulation were unsuccessful. The tumor was found to be easily transplanted.