Carbon monoxide generation from tin- and zinc-protoporphyrin by tissue homogenates.
Both heme and tin-protoporphyrin (TP), but not zinc-protoporphyrin (ZP), supported significant NADPH-stimulated, concentration-dependent CO production in all tissues. These rates, for 400 microM substrate, ranged: for heme 0.52 (intestine) to 4.18 (spleen); for TP 0.08 (kidney) to 0.71 (liver); and for ZP 0.01 (liver) to 0.25 (kidney) nmoles CO/hr/mg protein. All three metalloporphyrins (400 microM) supported concentration-dependent CO production in the absence of NADPH. The rates ranged: for heme 0.31 (kidney) to 0.80 (spleen); for TP 0.41 (kidney) to 1.04 (intestine); and for ZP 0.12 (kidney) to 0.51 (spleen) nmoles/hr/mg protein. We conclude that both TP and ZP are subject to in vitro degradation by 13,000 x g supernatants of adult rat organs via CO-producing reactions.
Vreman
H J
HJ
Department of Pediatrics, Stanford University School of Medicine, CA 94305.
Stevenson
D K
DK
D000818:Animals; D002248:Carbon Monoxide / Q000378:metabolism*; D005260:Female; D006418:Heme / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D008665:Metalloporphyrins; D009928:Organ Specificity; D011166:Porphyrins / Q000378:metabolism*; D011524:Protoporphyrins / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000378:metabolism
D008665:Metalloporphyrins; D011166:Porphyrins; D011524:Protoporphyrins; C017803:zinc protoporphyrin; D006418:Heme; D002248:Carbon Monoxide; C032628:tin protoporphyrin IX