In Vitro Pharmacology of Mitragynine at α-Adrenoceptors.

ABSTRACT: Mitragynine is a psychoactive alkaloid in Mitragyna speciosa with unique polypharmacology at G protein-coupled receptors. In addition to its well-known partial agonist activity at opioid receptors, mitragynine is an antagonist at human α_2A-adrenoceptors (α_2ARs), as measured in an in vitro GTPγS G protein assay. Mitragynine's in vitro α_2AR antagonist pharmacology contrasts with rat behavioral pharmacology studies that suggest mitragynine behaves as an in vivo agonist at rat α₂Rs. This study investigates this apparent discrepancy using recombinant α-adrenoceptors and a range of orthogonal signal transducers. We evaluated whether mitragynine activates any of seven Gα_i/o proteins coupled to α_2A, α_2B, and α

SUBMITTER: Chen Y 

PROVIDER: S-EPMC12679550 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature