Carbon monoxide

Carbon monoxide is a colorless, odorless, and tasteless gas used primarily as a marker of respiratory status in spirometry tests. It exerts its biological effects by binding strongly to heme-containing proteins such as hemoglobin and myoglobin. The affinity of carbon monoxide for hemoglobin is over 200 times greater than that of oxygen, leading to the formation of carboxyhemoglobin (COHb), which reduces the oxygen-carrying capacity of blood and impairs tissue oxygen delivery. Carbon monoxide also binds to other heme proteins involved in critical physiological processes including nitric oxide signaling (nitric oxide synthase, guanylyl cyclase), prostaglandin synthesis (cyclooxygenase), mitochondrial respiration (cytochrome c oxidase), steroid metabolism (cytochrome P450), redox balance (catalase, peroxidases), and regulation of circadian rhythm via transcription factors like NPAS2. While high levels are toxic and can cause hypoxic injury—especially in organs with high oxygen demand such as the brain and heart—recent research has explored therapeutic uses for controlled low-dose administration due to its anti-inflammatory and organ-protective properties[1][4][6].

Other names

COcarbonic oxideflue gasexhaust gas