J. Anim Sci.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Larson, B. T.
Right arrow Articles by Turner, J. T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Larson, B. T.
Right arrow Articles by Turner, J. T.

Journal of Animal Science, Vol 72, Issue 11 2905-2910, Copyright © 1994 by American Society of Animal Science

JOURNAL ARTICLE

D2 dopamine receptor response to endophyte-infected tall fescue and an antagonist in the rat

B. T. Larson, D. M. Sullivan, M. D. Samford, M. S. Kerley, J. A. Paterson and J. T. Turner
Department of Animal Sciences, University of Missouri, Columbia 65211.

Effects on rat brain D2 dopamine receptors by endophyte-infected tall fescue seed consumption and antagonist injection were characterized. Forty-eight male Wistar rats (225 g) in three separate trials were exposed to either 22 or 32 degrees C. Diets, to maintain similar concentrations of ergovaline, contained 10% (Trial 1) or 15% (Trials 2 and 3) endophyte-infected (E+; 325 average ppb of ergovaline) or uninfected (E-; 0 ppb of ergovaline) tall fescue seed. Rats were injected i.p. daily with either placebo (PL) or an experimental D2 dopamine antagonist (DA, .0375 mg/kg BW). No effects (P > .10) on diet DM intake by E+ ingestion or DA injection were detected at 22 degrees C. However, ingestion of E+ reduced (P < .01) and injection of DA improved (P < .05) DM intake of rats housed in 32 degrees C (11.1 vs 15.4 g of DM/d for E+ vs E-, respectively). Whole brain D2 dopamine receptor density (Bmax) and mRNA were reduced (P < .05) by E+ and increased (P < .05) by DA in Trial 1. No treatment effects (P > .10) on cerebral cortex alpha 1- and alpha 2-adrenergic or striatal D2 dopamine receptor Bmax were measured in Trials 2 and 3. In summary, dietary E+ reduced whole brain D2 dopamine mRNA and Bmax, whereas injection of DA increased D2 dopamine mRNA. Thus, long-term regulation of monoamine receptors seems to be affected by E+ ingestion or DA injection.




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1994 by the American Society of Animal Science.