The measurement of endogenous carbon monoxide production

2012 ◽  
Vol 112 (11) ◽  
pp. 1949-1955 ◽  
Author(s):  
Ronald F. Coburn

Recent findings that heme oxygenase-1 can be induced by oxidative stress and inflammation in many different cellular systems, and that carbon monoxide (CO) produced as a by-product of this enzyme is a signaling molecule, have generated a major research area with hundreds of studies published over the last few years. The measurement of expired CO concentration has been used in humans as a biomarker of induced heme oxygenase resulting from inflammation or oxidative stress, but a precise method of measuring endogenous CO production that can be easily used to study patients is needed. The present study describes such a method. The described method allows calculation of the rate of heme catabolism with a precision of ±2 μmol/h, ∼10% of the mean normal rate in subjects used in this investigation. This method, which is subject-patient friendly, precise, and inexpensive to perform, should be applicable to studies performed on humans with induced heme oxygenase and studies of effects of therapy for inflammatory and hemolytic diseases.

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Edyta Korbut ◽  
Tomasz Brzozowski ◽  
Marcin Magierowski

Oxidative stress reflects an imbalance between oxidants and antioxidants in favor of the oxidants capable of evoking tissue damage. Like hydrogen sulfide (H2S) and nitric oxide (NO), carbon monoxide (CO) is an endogenous gaseous mediator recently implicated in the physiology of the gastrointestinal (GI) tract. CO is produced in mammalian tissues as a byproduct of heme degradation catalyzed by the heme oxygenase (HO) enzymes. Among the three enzymatic isoforms, heme oxygenase-1 (HO-1) is induced under conditions of oxidative stress or tissue injury and plays a beneficial role in the mechanism of protection against inflammation, ischemia/reperfusion (I/R), and many other injuries. According to recently published data, increased endogenous CO production by inducible HO-1, its delivery by novel pharmacological CO-releasing agents, or even the direct inhalation of CO has been considered a promising alternative in future experimental and clinical therapies against various GI disorders. However, the exact mechanisms underlying behind these CO-mediated beneficial actions are not fully explained and experimental as well as clinical studies on the mechanism of CO-induced protection are awaited. For instance, in a variety of experimental models related to gastric mucosal damage, HO-1/CO pathway and CO-releasing agents seem to prevent gastric damage mainly by reduction of lipid peroxidation and/or increased level of enzymatic antioxidants, such as superoxide dismutase (SOD) or glutathione peroxidase (GPx). Many studies have also revealed that HO-1/CO can serve as a potential defensive pathway against oxidative stress observed in the liver and pancreas. Moreover, increased CO levels after treatment with CO donors have been reported to protect the gut against formation of acute GI lesions mainly by the regulation of reactive oxygen species (ROS) production and the antioxidative activity. In this review, we focused on the role of H2S and NO molecular sibling, CO/HO pathway, and therapeutic potential of CO-releasing pharmacological tools in the regulation of oxidative stress-induced damage within the GI tract with a special emphasis on the esophagus, stomach, and intestines and also two solid and important metabolic abdominal organs, the liver and pancreas.


2021 ◽  
Vol 22 (4) ◽  
pp. 1514 ◽  
Author(s):  
Akihiro Yachie

Since Yachie et al. reported the first description of human heme oxygenase (HO)-1 deficiency more than 20 years ago, few additional human cases have been reported in the literature. A detailed analysis of the first human case of HO-1 deficiency revealed that HO-1 is involved in the protection of multiple tissues and organs from oxidative stress and excessive inflammatory reactions, through the release of multiple molecules with anti-oxidative stress and anti-inflammatory functions. HO-1 production is induced in vivo within selected cell types, including renal tubular epithelium, hepatic Kupffer cells, vascular endothelium, and monocytes/macrophages, suggesting that HO-1 plays critical roles in these cells. In vivo and in vitro studies have indicated that impaired HO-1 production results in progressive monocyte dysfunction, unregulated macrophage activation and endothelial cell dysfunction, leading to catastrophic systemic inflammatory response syndrome. Data from reported human cases of HO-1 deficiency and numerous studies using animal models suggest that HO-1 plays critical roles in various clinical settings involving excessive oxidative stress and inflammation. In this regard, therapy to induce HO-1 production by pharmacological intervention represents a promising novel strategy to control inflammatory diseases.


2021 ◽  
Vol 22 (15) ◽  
pp. 8253
Author(s):  
Jung-Yeon Kim ◽  
Yongmin Choi ◽  
Jaechan Leem ◽  
Jeong Eun Song

Cholestatic liver diseases can progress to end-stage liver disease and reduce patients’ quality of life. Although their underlying mechanisms are still incompletely elucidated, oxidative stress is considered to be a key contributor to these diseases. Heme oxygenase-1 (HO-1) is a cytoprotective enzyme that displays antioxidant action. It has been found that this enzyme plays a protective role against various inflammatory diseases. However, the role of HO-1 in cholestatic liver diseases has not yet been investigated. Here, we examined whether pharmacological induction of HO-1 by cobalt protoporphyrin (CoPP) ameliorates cholestatic liver injury. To this end, a murine model of 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) diet feeding was used. Administration of CoPP ameliorated liver damage and cholestasis with HO-1 upregulation in DDC diet-fed mice. Induction of HO-1 by CoPP suppressed the DDC diet-induced oxidative stress and hepatocyte apoptosis. In addition, CoPP attenuated cytokine production and inflammatory cell infiltration. Furthermore, deposition of the extracellular matrix and expression of fibrosis-related genes after DDC feeding were also decreased by CoPP. HO-1 induction decreased the number of myofibroblasts and inhibited the transforming growth factor-β pathway. Altogether, these data suggest that the pharmacological induction of HO-1 ameliorates cholestatic liver disease by suppressing oxidative stress, hepatocyte apoptosis, and inflammation.


2003 ◽  
Vol 4 (1) ◽  
Author(s):  
Dirk-Jan Slebos ◽  
Stefan W Ryter ◽  
Augustine MK Choi

PLoS ONE ◽  
2013 ◽  
Vol 8 (5) ◽  
pp. e64372 ◽  
Author(s):  
André Quincozes-Santos ◽  
Larissa Daniele Bobermin ◽  
Alexandra Latini ◽  
Moacir Wajner ◽  
Diogo Onofre Souza ◽  
...  

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