| 11557597 |
Fu XW, Wang D, Pan J, Farragher SM, Wong V, Cutz E: Neuroepithelial bodies in mammalian lung express functional serotonin type 3 receptor. Am J Physiol Lung Cell Mol Physiol. 2001 Oct;281(4):L931-40.
Serotonin (5-HT) type 3 receptor (5-HT (3)-R) is a ligand-gated ion channel found primarily in the central and peripheral nervous system. We report expression and functional characterization of 5-HT (3)-R in pulmonary neuroepithelial body (NEB) cells. Using nonisotopic in situ hybridization, we demonstrate expression of 5-HT (3)-R mRNA in NEB cells in the lungs of different mammals (hamster, rabbit, mouse, and human). Dual immunocytochemistry (for 5-HT and 5-HT (3)-R) and confocal microscopy localized 5-HT (3)-R on NEB cell plasma membrane from rabbit. The electrophysiological characteristics of 5-HT (3)-R in NEB cells were studied in fresh slices of neonatal hamster lung using the whole cell patch-clamp technique. Application of the 5-HT (5-150 microM) and 5-HT (3)-R agonist 2-methyl-5-HT (5-150 microM) induced inward currents in a concentration-dependent manner. The 5-HT-induced current was blocked (76.5 +/- 5.9%) by the specific 5-HT (3)-R antagonist ICS-205-930 (50 microM), whereas katanserin and p-4-iodo-N-(2-[4-(methoxyphenyl)-1-piperazinyl] ethyl)-N-2-pyridinylbenzami de had minimal effects. Forskolin had no effect on desensitization and amplitude of the 5-HT-induced current. The reduction of Ca (2+) and Mg (2+) in the extracellular solution enhanced the amplitude of the 5-HT-induced current because of slower desensitization. Our studies suggest that 5-HT (3)-R in NEB cells may function as an autoreceptor and may potentially be involved in modulation of hypoxia signaling. |
1(0,0,0,1) |