Hemoglobin Inhibitors

Hemoglobin inhibitors predominantly function by impairing the protein's oxygen-carrying capacity. A significant portion of these inhibitors act through the formation of methemoglobin, a form of hemoglobin where the iron in the heme group is oxidized to the Fe^3+ state. In this state, hemoglobin cannot bind oxygen, and thus its transportation function is hindered. Agents like Nitrite, Sodium dithionite, Naphthalene, Aniline, Chloroform, Nitrobenzene, and Phenacetin either directly oxidize hemoglobin or introduce metabolites that produce this oxidized form.

Another mode of inhibition is the direct binding to the iron within the heme group of hemoglobin. Carbon monoxide exemplifies this mechanism. CO binds approximately 210 times more tightly to hemoglobin than oxygen, leading to a significant reduction in hemoglobin's ability to transport the latter. Similarly, compounds like Cyanide, Hydrogen sulfide, and Sodium azide interact directly with hemoglobin's heme group, preventing effective oxygen binding.