Circadian variation of mitochondrial succinic dehydrogenase and microsomal cytochrome P-450 dependent monooxygenase activity in the liver of sexually immature and mature rats.
The experiments were carried out on 60-day and 6-month old male Wistar rats within 48 h in one season of the year (autumn). Material was collected every four hours, beginning from 10:00 a.m. The present results indicate that the fluctuations of cytochrome P-450 content in liver microsomes in both age groups occurred in a 12 h rhythm with peaks at 10:00 and 22:00. Similarly, the activity fluctuations of NADPH-cytochrome c reductase showed the 12 h rhythm, with maximal values at 10:00 and 22:00, too. The cytochrome b5 content in a younger group of rats oscillated apparently in the 12 h rhythm with the maximal values at 06:00 and 18:00. The activity course of cytochrome b5 in 6-month-old rats revealed a 24 h rhythm and two maxima of the activity were found: the first one at 14:00 and the second one at 02:00. NADH-cytochrome b5 reductase in both age groups showed a 24 h rhythm, also the activity fluctuations of succinic dehydrogenase showed a tendency to 24-h rhythmicity, and the differences between minimal and maximal values were statistically insignificant. The results of our experiment have shown some correlations between the activity of microsomal system of mixed-function oxidases and mitochondrial respiratory enzyme.
Department of Histology and Embryology, Silesian School of Medicine, Katowice-Ligota, Poland.
E
E
Wielgus-Serafińska
A
A
Plewka
M
M
Kamiński
D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D015786:Cytochromes b5 / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D008930:Mitochondria, Liver / Q000201:enzymology*; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012741:Sexual Maturation / Q000502:physiology*; D013385:Succinate Dehydrogenase / Q000378:metabolism*
D015786:Cytochromes b5; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D013385:Succinate Dehydrogenase; D009251:NADPH-Ferrihemoprotein Reductase