1. Plural of methemoglobin; forms of hemoglobin in which the iron in the heme group has been oxidized from the ferrous (Fe²⁺) to the ferric (Fe³⁺) state, reducing the protein's ability to bind and transport oxygen.
Usage: medical/biochemistry term; also spelled methaemoglobins in British English

Examples

• Elevated levels of methemoglobins in the blood can result from exposure to certain chemicals or medications.
• The patient's methemoglobins were measured to diagnose methemoglobinemia.
• Nitrite poisoning causes the formation of methemoglobins, which impairs oxygen delivery to tissues.
• Doctors use pulse oximetry and blood tests to detect abnormal methemoglobins.
• Reducing agents like ascorbic acid can help convert methemoglobins back to normal hemoglobin.