1. That which carries a message. 2. Having message-carrying properties.
- first m. a hormone that binds to a receptor on the surface cell and, in so doing, communicates with intracellular metabolic processes.
- second m. an intermediary molecule that is generated as a consequence of hormone-receptor interaction; e.g., see adenosine 3′,5′-cyclic monophosphate, guanosine 3′,5′-cyclic monophosphate, calcium, inositide.
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mes·sen·ger 'mes-ən-jər n
1) a substance (as a hormone) that mediates a biological effect see FIRST MESSENGER, SECOND MESSENGER
2) MESSENGER RNA
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mes·sen·ger (mesґən-jər) an information carrier such as a hormone or an electrical impulse.Medical dictionary. 2011.