Changes in the content and intracellular distribution of coenzyme Q homologs in rabbit liver during growth.
In order to determine whether coenzyme Q (CoQ) homologs which coexist in mammals play the same or different roles, the concentrations of coenzyme Q9 (CoQ9) and coenzyme Q10 (CoQ10) were analyzed in Japanese White (JW) rabbit tissues during growth, together with the intracellular distribution of these two CoQ homologs. In liver %CoQ9 (total [CoQ9] X 100/total [CoQ9] + total [CoQ10]) was approx. 40% until 3 weeks after birth, and then gradually decreased to 20%. In kidney, %CoQ9 decreased from 8% (1 week) to 1% (7 weeks). In heart, %CoQ9 was 3%, and in the brain, 2%, and these values did not change with growth. Most CoQ9 was present in the cytosolic fraction, whereas most CoQ10 was in the mitochondrial fraction. There was but minor change in the intracellular distribution of CoQ9 and CoQ10 in rabbit liver between 2 weeks and 7 weeks of age. These results suggest that CoQ9 and CoQ10 may play different roles in their physiological actions as antioxidant or component of the mitochondrial respiratory chain.
Matsura
T
T
Department of Biochemistry, Hiroshima University School of Medicine, Japan.
Yamada
K
K
Kawasaki
T
T
D000818:Animals; D001921:Brain / Q000201:enzymology; D003600:Cytosol / Q000201:enzymology; D007668:Kidney / Q000201:enzymology; D008099:Liver / Q000201:enzymology* / Q000254:growth & development; D051379:Mice; D008813:Mice, Inbred ICR; D008861:Microsomes / Q000201:enzymology; D008928:Mitochondria / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains; D014451:Ubiquinone / Q000378:metabolism*
D014451:Ubiquinone; C025204:Ubiquinone Q2; C030571:ubiquinone 9