Heme regulation in mouse mammary carcinoma and liver of tumor bearing mice--I. Effect of allyl-isopropylacetamide and veronal on delta-aminolevulinate synthetase, cytochrome P-450 and cytochrome oxidase.
1. Basal levels and allyl-isopropylacetamide (AIA) or veronal induced levels of delta-aminolevulinate synthetase (ALA-S), cytochrome P-450 (cyt P-450) and cytochrome oxidase were determined in tumor (T) and liver of both normal mice (NM) and T bearing mice (TBM). 2. Basal levels of ALA-S were nearly the same in either source. The amount of cyt P-450 was lower in TBM liver than in NM liver, and no detectable in T. While the basal activity of cytochrome oxidase in TBM liver and T were higher than those of NM liver. 3. In AIA intoxicated animals there was a lower induction of ALA-S in liver of TBM than in NM liver. There was no induction in T ALA-S. The loss of cyt P-450 was less in TBM liver when compared with NM liver. 4. The induction level of cyt P-450 after veronal administration was nearly the same in liver of both TBM and NM. 5. We conclude that lower induction of liver ALA-S activity in TBM liver is due to correspondingly lower drug metabolism ability of TBM liver. Otherwise our results suggest that the control mechanism operating in T and probably in its original tissue are different from those described for normal liver.
Navone
N M
NM
Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP) (CONICET, FCEN, UBA), Ciudad Universitaria, Buenos Aires, Republica Argentina.
Polo
C F
CF
Dinger
R M
RM
Batlle
A M
AM
D000624:5-Aminolevulinate Synthetase / Q000378:metabolism*; D000502:Allylisopropylacetamide / Q000494:pharmacology*; D000818:Animals; D001462:Barbital / Q000494:pharmacology*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D003576:Electron Transport Complex IV / Q000378:metabolism*; D004790:Enzyme Induction / Q000187:drug effects; D006418:Heme / Q000096:biosynthesis*; D008099:Liver / Q000201:enzymology*; D008297:Male; D008325:Mammary Neoplasms, Experimental / Q000201:enzymology*; D051379:Mice; D008807:Mice, Inbred BALB C
D000502:Allylisopropylacetamide; D006418:Heme; D001462:Barbital; D003577:Cytochrome P-450 Enzyme System; D003576:Electron Transport Complex IV; D000624:5-Aminolevulinate Synthetase