| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1986: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1985: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Research Abstract |
Phenylhydrazine reacts with hemoglobin in erythrocytes to produce the precipitation of Heinz body which induces hemolysis. A significant amount of research effort has been devoted to understanding the process leading to Heinz body formation, which is associated with irreversible oxidative denaturation of hemoglobin. Heme modification has been demonstrated by the detection of N-phenylated protoporphyrin in the in vitro reaction of phenylhydrazine with oxyhemoglobin. In this paper, phenylhydrazine was given to rat, and the in vivo phenylation of heme of hemoglobin was examined with the isolation of the phenylated porphyrin from the treated animal. The blood and the spleen of the rat were treated with a solution of acidic methanol and zinc ion to isolate a green pigment. The pigment was resolved into the two, I and II, by thin layer chromatography. Pigment I was a mixture of two isomers of zinc complex of esterified N-phenylprotoporphyrin IX, in which vinyl-substituted pyrrole rings A and
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B were phenylated, and pigment II was a mixture of two isomers of the porphyrin complex with the N-phenyl group on propionic acid-substituted rings C and D.
Phenyl radical produced by the reaction of oxyhemoglobin with phenylhydrazine reacts at heme iron to form the phenyliron complex, and the pigments are formed by the migration of the phenyl group from the iron to the pyrrole nitrogen by aerobic treatment with acidic methanol used for the isolation of pigments. Thus, the blood of the phenylhydrazine-treated rat must contain hemoglobin with iron-phenyl heme.
The insertion of exogenous large ligand of phenyl group to the heme pocket of hemoglobin is expected to alter the contact to lead to destabilization of hemoglobin molecule. The molecule diminishes its resistance to oxidation by oxidants produced concomitantly with phenyl radical by the reaction of phenylhydrazine with oxyhemoglobin, and is led to denaturation to form Heinz bodies. The detection of the modified heme in the treated rat provides a phenomenon for the proposed mechanism for phenylhydrazine action to explain. Less
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