Heme oxygenase converts heme to carbon monoxide, biliverdin (subsequently converted to bilirubin), and free iron. Pharmacological induction of heme oxygenase 1 has an antihypertensive effect in the spontaneously hypertensive rat. The present study investigated whether upregulation of heme oxygenase 1 by hemin reduces endothelial dysfunction in this animal. Thirty-six-week-old rats were divided ...

The mechanism by which the terminal respiratory enzyme, cytochrome oxidase, reduces molecular oxygen is still a matter of speculation. Fundamental to an understanding of this chemical mechanism is a clarification of the structure of the prosthetic group of this enzyme. Extensive work by many investigators (l-5) has clearly established that this prosthetic group is an iron porphyrin compound. Th...

Increased susceptibility to bacterial and viral infections and dysfunctional erythropoiesis are characteristic of malaria and other hemolytic hemoglobinopathies. High concentrations of free heme are common in these conditions but little is known about the effect of heme on adaptive immunity and erythropoiesis. Herein, we investigated the impact of heme (hemin) administration on immune parameter...

Ferrous Hb contributes to cerebral vasospasm after subarachnoid hemorrhage, although the mechanisms involved are uncertain. The hypothesis that cytotoxic effects of ferrous Hb on smooth muscle cells contribute to vasospasm was assessed. Cultured rat basilar artery smooth muscle cells were exposed to pure Hb, dog erythrocyte hemolysate, or Hb breakdown products; and heme oxygenase (HO-1 and HO-2...

The mechanism by which the terminal respiratory enzyme, cytochrome oxidase, reduces molecular oxygen is still a matter of speculation. Fundamental to an understanding of this chemical mechanism is a clarification of the structure of the prosthetic group of this enzyme. Extensive work by many investigators (l-5) has clearly established that this prosthetic group is an iron porphyrin compound. Th...

A novel photoelectrochemical sensing strategy is designed for DNA detection on the basis of in situ generation of an electron acceptor via the catalytic reaction of hemin toward H2O2. The photoelectrochemical platform was established by sequential assembly of near-infrared CdTe quantum dots, capture DNA, and a hemin-labeled DNA probe to form a triple-helix molecular beacon (THMB) structure on a...

The inducible isoform of haem oxygenase (HO-1) has been proposed as an effective system to counteract oxidant-induced cell injury. In several circumstances, this cytoprotective effect has been attributed to increased generation of the antioxidant bilirubin during haem degradation by HO-1. However, a direct implication for HO-1-derived bilirubin in protection against oxidative stress remains to ...

The prevention and treatment of acute chest syndrome (ACS) is a major clinical concern in sickle cell disease (SCD). However, the mechanism underlying the pathogenesis of ACS remains elusive. We tested the hypothesis that the hemolysis byproduct hemin elicits events that induce ACS. Infusion of a low dose of hemin caused acute intravascular hemolysis and autoamplification of extracellular hemin...

BACKGROUND The aim of this study is to investigate the protective effects of hemin (the heme oxygenase-1 [OH-1] inducer) against nephrotoxic effects induced by cisplatin [cis-diamminedichloroplatinum II (CP)] in male rats. METHODS The evaluation was performed through monitoring renal redox parameters: lipid peroxidation (LPO), glutathione peroxidase (GPx), superoxide dismutase (SOD), glutathi...

The effect of pressure on the M6ssbauer resonance in hemin and in iron phthalocyanine has been measured. In these initial studies unenriched compounds were used. The hemin was material supplied by Dr. Lowell Hager of the Division of Biochemistry. The iron phthalocyanine was obtained from E. I. DuPont de Nemours Company and was resublimed in our laboratory. The high-pressure M6ssbauer techniques...