Abstract

Sarcoma 180 grew for only 10–14 days when implanted in bilaterally adrenalectomized male Swiss mice. The tumors completely regressed within 30 days. Untreated adrenalectomized mice never had tumors larger than 15 mm. in diameter. Adrenalectomy of mice after the tumor was established also resulted in regression of Sarcoma 180. Daily injections of cortisol acetate or corticosterone at dosages from 0.3 to 13.3 mg/kg did not prevent the tumor regression in adrenalectomized mice. Daily injections of deoxycorticosterone acetate at dosages from 1.7 to 13.3 mg/kg or aldosterone at 0.5 mg/kg reduced the number of regressions and allowed the tumors to grow larger than 15 mm. in diameter before the host died. Growth of Sarcoma 180 was dependent on mineralocorticoid activity. A relationship between sodium and potassium metabolism and the growth of the tumor was suggested.