Opposite effects of lanthanum on different types of nicotinic acetylcholine receptors.
The effects of lanthanum (La3+) were studied on muscle and neuronal nicotinic acetylcholine receptors (AChRs) expressed in Xenopus oocytes. La3+ exerts a dose-dependent positive modulation on alpha1 beta1 gamma8 muscle AChRs, whereas it modulates negatively either alpha2 beta2, alpha2 beta4 or alpha3 beta4 neuronal AChRs. Moreover, La3+ appears to accelerate the desensitization of neuronal receptors. In both muscle and neuronal AChRs, the respective potentiating or inhibiting effects of La3+ on the ACh-currents are voltage-independent, suggesting that La3+ is acting at a site located in the external domain of the receptor.
García-Colunga
J
J
Department of Psychobiology, University of California, Irvine 92697-4550, USA.
Miledi
R
R
D000818:Animals; D004594:Electrophysiology; D007811:Lanthanum / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009865:Oocytes; D011978:Receptors, Nicotinic / Q000187:drug effects*; D014981:Xenopus
D011978:Receptors, Nicotinic; D007811:Lanthanum