The Sound of Evolution
Pentazocine
Mechanism of action:
Pentazocine is an opioid. Pentazocine mainly activates the κ-opioid receptor. Through Gi/o protein coupling, it inhibits adenylyl cyclase, lowers cAMP levels, suppresses presynaptic calcium influx, and reduces the release of pain-related neurotransmitters such as glutamate and substance P, thereby decreasing pain signal transmission. It also activates postsynaptic potassium channels, causing neuronal membrane hyperpolarization. Pentazocine has relatively weak activity at the μ-opioid receptor.
Reference(s):
1. Chien CC et al. (1995). (-)-Pentazocine analgesia in mice: interactions with a sigma receptor system. Eur J Pharmacol.
2. Colabufo NA et al. (2009). In vitro and ex vivo characterization of sigma-1 and sigma-2 receptors: agonists and antagonists in biological assays. Cent Nerv Syst Agents Med Chem.
3. Dun Y et al. (2007). Prevention of excitotoxicity in primary retinal ganglion cells by (+)-pentazocine, a sigma receptor-1 specific ligand. Invest Ophthalmol Vis Sci.