Central administration of dipeptides, beta-alanyl-BCAAs, induces hyperactivity in chicks.
BACKGROUND
Carnosine (beta-alanyl-L-histidine) is a putative neurotransmitter and has a possible role in neuron-glia cell interactions. Previously, we reported that carnosine induced hyperactivity in chicks when intracerebroventricularly (i.c.v.) administered. In the present study, we focused on other beta-alanyl dipeptides to determine if they have novel functions.


RESULTS
In Experiment 1, i.c.v. injection of beta-alanyl-L-leucine, but not beta-alanyl-glycine, induced hyperactivity behavior as observed with carnosine. Both carnosine and beta-alanyl-L-leucine stimulated corticosterone release. Thus, dipeptides of beta-alanyl-branched chain amino acids were compared in Experiment 2. The i.c.v. injection of beta-alanyl-L-isoleucine caused a similar response as beta-alanyl-L-leucine, but beta-alanyl-L-valine was somewhat less effective than the other two dipeptides. beta-Alanyl-L-leucine strongly stimulated, and the other two dipeptides tended to stimulate, corticosterone release.


CONCLUSIONS
These results suggest that central beta-alanyl-branched chain amino acid stimulates activity in chicks through the hypothalamus-pituitary-adrenal axis. We named beta-alanyl-L-leucine, beta-alanyl-L-isoleucine and beta-alanyl-L-valine as Excitin-1, Excitin-2 and Excitin-3, respectively.
Tsuneyoshi
Yousuke
Y
Laboratory of Advanced Animal and Marine Bioresources, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan. be206112@s.kyushu-u.ac.jp <be206112@s.kyushu-u.ac.jp>
Tomonaga
Shozo
S
Asechi
Mari
M
Morishita
Koji
K
Denbow
D Michael
DM
Furuse
Mitsuhiro
M
D000818:Animals; D000831:Animals, Newborn; D002336:Carnosine / Q000008:administration & dosage*; D002645:Chickens; D004151:Dipeptides / Q000008:administration & dosage*; D006948:Hyperkinesis / Q000139:chemically induced* / Q000503:physiopathology*; D007276:Injections, Intraventricular; D008297:Male; D014828:Vocalization, Animal / Q000187:drug effects*
D004151:Dipeptides; C028872:alanylglycine; D002336:Carnosine