Abstract
We investigated whether 3-methylcholanthrene (3MC) or phenobarbital (PB) which inhibit hepatocarcinogenesis of 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) block the decrease in intra- and extracellular pH (pHi and pHe) in the livers of rats on a diet containing 0.06% 3'-Me-DAB. In rats treated with 3MC or PB alone, pHe and pHi levels remained within normal limits. In rats on the 3'-Me-DAB diet, pretreatment with 3MC or PB prevented a pH decrease in the 1st and 5th weeks after inception of the 3'-Me-DAB diet. In partially hepatectomized rats on a basal diet, no pHe or pHi decrease in the regenerating liver was noted at 24 and 48 hr after hepatectomy. However, in partially hepatectomized rats on the 3'-Me-DAB diet, a significant pHi decrease in the regenerating liver was observed. In rats administered with 50 ppm diethylnitrosamine in place of drinking water, liver nodules developed. However, pHe and pHi dropped only slightly. The administration of CCl4 or bromobenzene effected no significant decrease in pHe or pHi, however, a dose-response correlation was found to exist for CCl4.
