Isolation of an N-alkylprotoporphyrin IX from chick embryo livers following the administration of 3,5-diethoxycarbonyl-1,4-dihydro-4-ethyl-2,6-dimethylpyridine.
The ferrochelatase-lowering activity of 3,5-diethoxycarbonyl-1,4-dihydro-2,4,6-trimethylpyridine (DDC) analogues in chick embryo hepatocyte culture has been assumed to be due to the formation of an N-alkylprotoporphyrin IX. This assumption required confirmation. For this reason the 4-ethyl analogue of DDC was administered to phenobarbital-pretreated 19-day-old chick embryos. This resulted in hepatic accumulation of a green pigment with ferrochelatase-inhibitory activity. The green pigment was identified as an N-alkylprotoporphyrin IX by comparison of the electronic absorption spectra of its dimethyl ester and Zn complex with the corresponding spectra obtained from synthetic N-ethylprotoporphyrin IX.
McCluskey
S A
SA
Department of Pharmacology and Toxicology, Queen's University, Kingston, Ont., Canada.
Sutherland
E P
EP
Racz
W J
WJ
Marks
G S
GS
D000818:Animals; D002478:Cells, Cultured; D002642:Chick Embryo; D003997:Dicarbethoxydihydrocollidine / Q000031:analogs & derivatives / Q000494:pharmacology*; D004095:Dihydropyridines / Q000494:pharmacology*; D005294:Ferrochelatase / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008190:Lyases / Q000378:metabolism*; D010634:Phenobarbital / Q000494:pharmacology; D011166:Porphyrins / Q000302:isolation & purification*; D011524:Protoporphyrins / Q000302:isolation & purification* / Q000378:metabolism; D013053:Spectrophotometry
D004095:Dihydropyridines; D011166:Porphyrins; D011524:Protoporphyrins; C030826:3,5-dicarbethoxy-2,6-dimethyl-4-ethyl-1,4-dihydropyridine; D003997:Dicarbethoxydihydrocollidine; D008190:Lyases; D005294:Ferrochelatase; D010634:Phenobarbital