Induction by X-irradiation of adenosine triphosphatase-deficient islands in the rat liver and their characterization.
The potential of X-rays to induce preneoplastic lesions in the rat liver was studied in order to clarify the reason why X-rays are ineffective in inducing hepatocellular carcinoma in this animal. Male newborn rats at 8 or 22 days of age received whole body X-ray irradiation of 100 to 400 rads. After weaning they were fed either basal diet or a diet containing 0.05% phenobarbital as a promoter. X-rays induced numerous adenosine triphosphatase-deficient islands appearing in the liver by wk 22 of age. However, they were generally small, gamma-glutamyl transpeptidase-negative, and did not clearly respond to the promoting stimulus of phenobarbital. No hepatic tumors were observed by 22 mo after radiation, even in phenobarbital-treated animals. Thus the X-ray-induced enzyme-altered islands differ somewhat qualitatively from those induced by potent hepatic carcinogens and their preneoplastic potential if at all present may be very low. Similarities between these X-ray-induced lesions and some types of spontaneous enzyme-altered islands are pointed out.
Kitagawa
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T
Nomura
K
K
Sasaki
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S
D000251:Adenosine Triphosphatases / Q000172:deficiency*; D000818:Animals; D002273:Carcinogens / Q000494:pharmacology; D004307:Dose-Response Relationship, Radiation; D008099:Liver / Q000201:enzymology / Q000473:pathology / Q000528:radiation effects*; D008297:Male; D010634:Phenobarbital / Q000494:pharmacology; D051381:Rats; D014965:X-Rays
D002273:Carcinogens; D000251:Adenosine Triphosphatases; D010634:Phenobarbital