title: Inhibition of dopamine and choline acetyltransferase concentrations in rat CNS neurons by rat alpha 1- and alpha 2-macroglobulins.
abstract: Previous studies have implicated human alpha-2-macroglobulin (alpha2M) as a potential regulator of neuronal development and function. Rat alpha-1-macroglobulin (alpha1M) and acute-phase alpha-2-macroglobulin (alpha2M) are murine homologues of human alpha2M. In this report, we tested the effect of intracranially infused serotonin-activated rat alpha1M (5HT-alpha1M) on the concentration of dopamine (DA) in the corpus striatum in vivo and the effect of 5HT-activated rat alpha1M and alpha2M on the choline acetyltransferase (ChAT) activity upon embryonic basal forebrain neurons in culture. The results show that direct infusion of 0.65 nmole rat 5HT-alpha1M into the adult rat corpus striatum produced a consistent attenuation upon striatal DA concentrations. This decrease was particularly prominent at 5-7 days post-infusion. In addition, rat 5HT-alpha1M and rat 5HT-alpha2M, like human 5HT-alpha2M, all significantly inhibited ChAT activity of embryonic rat cerebral cortex neurons. Although normal human alpha2M and rat alpha2M were either marginally or insignificantly inhibitory in this preparation, normal rat alpha1M dose-dependently inhibited ChAT activity. These results demonstrate that monoamine-activated alpha-macroglobulins from rat depress dopaminergic and cholinergic neurotransmitter systems in the CNS, and this suggests a potential regulatory role of these alpha-macroglobulins in neurotransmitter metabolism.
authors.affiliation: Department of Microbiology and Immunology, Northeastern Ohio Universities College of Medicine, Rootstown 44272, USA.
authors.forename: Y Q
authors.initials: YQ
authors.lastname: Hu
authors.forename: D J
authors.initials: DJ
authors.lastname: Liebl
authors.forename: D E
authors.initials: DE
authors.lastname: Dluzen
authors.forename: P H
authors.initials: PH
authors.lastname: Koo
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002795:Choline O-Acetyltransferase / Q000037:antagonists & inhibitors*; D003342:Corpus Striatum / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D004298:Dopamine / Q000032:analysis / Q000378:metabolism*; D018492:Dopamine Antagonists / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D007276:Injections, Intraventricular; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000494:pharmacology; D013238:Stereotaxic Techniques; D000511:alpha-Macroglobulins / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D018492:Dopamine Antagonists; D000511:alpha-Macroglobulins; D012701:Serotonin; D002795:Choline O-Acetyltransferase; D004298:Dopamine