Aprotinin and growth of Walker 256 carcinosarcoma in the rat.

Growth of the Walker 256 carcinosarcoma implanted within various sites in Spraque-Dawley rats was investigated in animals receiving twice daily i.p. injections of the antiprotease aprotinin. Although administration of aprotinin partially attenuated the growth and lethality of i.p. tumour, no effect of aprotinin was found on intramuscular tumour development. Furthermore, we were unable to demonstrate unequivocal growth inhibition by aprotinin of lung tumour colonies from i.v. injection of tumour cells. Histological examination of intramuscular and pulmonary tumours revealed little evidence of host cellular immune response in either saline- or aprotinin-treated rats.