Induction of heme oxygenase mRNA by cobalt protoporphyrin in rat liver.
The effect of cobaltic(III)-protoporphyrin on heme oxygenase activity and mRNA content was examined in vivo in the adult male rat liver. The activity of heme oxygenase, the rate-limiting enzyme in the degradation of heme, was enhanced, as expected, by cobalt protoporphyrin (25 mumol/kg body weight) in a time-dependent manner. Levels of enzyme activity were increased 2-fold by 8-16 h following treatment and were 6-fold higher than baseline values by 48 h. Administration of cobalt protoporphyrin resulted in a marked increase in heme oxygenase mRNA in the liver. Within 2 h of treatment, mRNA levels had increased 7.9-fold. The induction of heme oxygenase mRNA was maximal at 8 h when the levels were 58.5-fold above baseline. At every time point tested, the increase in heme oxygenase mRNA was several fold greater than that of enzyme activity.
Smith
T J
TJ
Department of Medicine, State University of New York, Buffalo.
Haque
S
S
Drummond
G S
GS
D000818:Animals; D015152:Blotting, Northern; D003035:Cobalt; D004790:Enzyme Induction / Q000187:drug effects; D006419:Heme Oxygenase (Decyclizing) / Q000235:genetics*; D008099:Liver / Q000201:enzymology*; D011524:Protoporphyrins / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D011524:Protoporphyrins; D012333:RNA, Messenger; D003035:Cobalt; D006419:Heme Oxygenase (Decyclizing)