title: Lithium inhibits internalization and endosomal processing of both neuropeptide Y (NPY) Y1 and transferrin receptors.
abstract: Low concentrations of Li+ reduce the rate of internalization of neuropeptide Y (NPY) Y1 receptors [M.S. Parker, S.L. Parker, J.K. Kane, Internalization of neuropeptide Y Y1 and Y5 and of pancreatic polypeptide Y4 receptors is inhibited by lithium in preference to sodium and potassium ions, Regul. Pept., 118 (2004) 67-74]. This Li+-induced decrease in Y1 receptor internalization could be alleviated by Y1 receptor agonists. As shown by fractionation on Percoll gradients, lithium treatment induces a concentration-related decrease of intermediate and higher endosomal densities that contain the internalized Y1 ligand-receptor complex. This indicates an inhibition of endosome processing and maturation. Internalization of human transferrin shows [Li+] sensitivity similar to that of the Y1 receptor, and a similar Li+-induced decrease in endosomal processing. Lithium treatment thus decreases activity of the endosome system shared in the recycling endocytosis of the Y1 and transferrin receptors.
authors.affiliation: Department of Microbiology and Molecular Cell Sciences, University of Memphis, Memphis, TN 38163, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Parker
authors.forename: Renu
authors.initials: R
authors.lastname: Sah
authors.forename: Ambikaipakan
authors.initials: A
authors.lastname: Balasubramaniam
authors.forename: Steven L
authors.initials: SL
authors.lastname: Parker
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D004305:Dose-Response Relationship, Drug; D011992:Endosomes / Q000187:drug effects* / Q000378:metabolism*; D008094:Lithium / Q000494:pharmacology*; D017476:Receptors, Neuropeptide Y / Q000378:metabolism*; D011990:Receptors, Transferrin / Q000378:metabolism*
chemical_list: D017476:Receptors, Neuropeptide Y; D011990:Receptors, Transferrin; C097212:neuropeptide Y-Y1 receptor; D008094:Lithium