Different effects of lobeline on neuronal and muscle nicotinic receptors

Lobeline is a plant alkaloid known to interact with cholinergic system. The effect of lobeline on neuronal alpha 3 beta 4 receptors expressed in COS cells and muscle embryonic alpha beta gamma delta receptors naturally expressed in TE671 cells was studied using a patch clamp technique. Our results show that lobeline inhibited responses to acetylcholine in human embryonic muscle nicotinic receptor in a pseudo noncompetitive manner. The responses of rat neuronal alpha 3 beta 4 receptors to a low concentration of acetylcholine were potentiated by a mixed occupation mechanism that corresponds to competitive potentiation. This potentiation turned into voltage dependent inhibition for alpha 3 beta 4 receptors was activated by a high concentration of acetylcholine. (C) 2014 Elsevier B.V. All rights reserved.