An important role in ensuring the functioning of respiratory chain belongs to cytochrome part, which includes complexes III (ubiquinol-cytochrome c oxidoreductase) and IV (cytochrome oxidase). The key components these enzymatic are heme-containing cytochromes, number depends on balance heme synthesis catabolism. δ-Aminolevulinate synthase catalyzes first step biosynthetic pathway, while oxygena...

Heme oxygenase-l is an essential enzyme in heme catabolism, and its human gene promoter contains a putative heat shock element (HHO-HSE). This study was designed to analyze the regulation of human heme oxygenase-l gene expression under thermal stress. The amounts of heme oxygenase-l protein were not increased by heat shock (incubation at 42°C) in human alveolar macrophages and in a human eryth...

The proinfammatory vasculotoxic effects of intravascular hemolysis are modulated by plasma hemoglobin and heme clearance via the haptoglobin/CD163 system and the hemopexin/CD91 system, respectively, and detoxification through the heme oxygenase/ferritin system. However, sudden or excessive hemolysis can overwhelm these protective systems leading to heme interacting with cells of the vasculature...

Chronic hypoxia increases the expression of a set of stress proteins (oxygen regulated proteins or ORPs) which is implicated in the development of drug resistance and radiation sensitivity in tumour cells. Five major ORPs have been documented, and two, ORP 80 and ORP 100, are considered to be identical to the glucose regulated stress proteins GRP78 and GRP94, respectively. We report here that O...

Carbon monoxide has been identified as an endogenous biological messenger in the brain. Heme oxygenase catalyzes the metabolism of heme to carbon monoxide and biliverdin. Previously, we have shown the involvement of carbon monoxide in central cardiovascular regulation, baroreflex modulation, and glutamatergic neurotransmission in the nucleus tractus solitarii of rats. We also showed that adenos...

Polychlorinated biphenyls (PCB) are potent inducers of hepatic microsomal CO-binding hemoprotein P-448 (P1-450) and of delta-aminolevulinate synthetase (ALAS) activity. Inorganic cobalt was able to block PCB induction of cytochrome P-448 and to modify the PCB effect on ALAS activity in a time-dependent manner. PCB were also found to decrease the activity of delta-aminolevulinic acid dehydratase...

Recent studies have identified and characterized the enzymatic mechanism by which hemoglobin-heme is converted to bilirubin. Under physiologic conditions the enzyme system, microsomal heme-oxygenase, is most active in the spleen followed by the liver and bone marrow, all of which are tissues that normally are involved in the sequestration and metabolism of red cells. Indirect evidence suggested...