RESUMO
Similar distortion of hypertensive response to epinephrine occurred in sarcoma-45-bearing rats, Walker carcinosarcoma-bearing rats, and hepatectomized rats. The response in the last-named was distorted on the 3rd postoperative day. The hypertensive response to epinephrine was restored after the regenerative processes in the liver were completed (7th-10th postoperative day). Distortion of the response in carcinosarcoma-bearing rats was detected beginning from the 4th day after transplantation in some of the animals and on the 14th day in the others; in all sarcoma 45-bearing rats distortion occurred by the 20th day. The pressor response was distorted usually under conditions of pharmacological block of the alpha-adrenergic receptors. It is assumed that in extensive proliferation of normal and neoplastic cells, substances exerting a selective blocking effect on the alpha-adrenoceptors of the blood vessels penetrate into circulation.