Modification of lung tumor growth by hyperoxia.
The effects of hyperoxia on lung tumor development were examined in mice and rats. In mice, exposure to 70% O2 prevented the development of urethan- or 3-methylcholanthrene-induced lung tumors. Dietary antioxidants [butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA)] were unable to prevent the inhibition of tumor development by oxygen, although BHT retained its capability to enhance tumor development in mouse lung. In visible-size tumors, oxygen did not depress DNA synthesis. Oxygen also reduced the number of pulmonary metastatic nodules after i.v. injection of mammary gland-derived carcinoma cells, but failed to inhibit growth of murine lung carcinoma or murine melanoma-derived cell lines. Rats treated with one single intratracheal instillation of 3-methylcholanthrene developed multiple lung lesions; their growth could be prevented by exposure of the animals to 40 or 70% O2. It is concluded that hyperoxia prevents development of transformed cells in vivo in the lung and may affect adversely the growth of selected cell lines metastatic to the lung.
D000818:Animals; D002083:Butylated Hydroxyanisole / Q000494:pharmacology; D002084:Butylated Hydroxytoluene / Q000494:pharmacology; D002455:Cell Division; D004247:DNA / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D008175:Lung Neoplasms / Q000473:pathology / Q000517:prevention & control* / Q000556:secondary; D008297:Male; D008748:Methylcholanthrene; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010100:Oxygen / Q000494:pharmacology*; D051381:Rats; D011916:Rats, Inbred F344
D002084:Butylated Hydroxytoluene; D002083:Butylated Hydroxyanisole; D008748:Methylcholanthrene; D004247:DNA; D010100:Oxygen