Dynorphin A(1-13) modulates apomorphine-induced behaviors using multidimensional behavioral analyses in the mouse.
The effects of intracerebroventricular injection of dynorphin A(1-13) on apomorphine-induced behavioral changes were investigated in the mouse using multidimensional behavioral analyses based upon a capacitance system. Although lower doses (0.1 or 0.3 mg/kg) of apomorphine were without marked effects on behaviors, a 0.56 mg/kg dose of the drug evoked a significant increase in rearing behaviors. Furthermore 1.0 and 3.0 mg/kg doses of apomorphine produced a marked increment in linear locomotion, circling and rearing. Dynorphin A(1-13) (3.0 or 10.0 microgram) itself had no effects on behaviors. The apomorphine (0.56 and 1.0 mg/kg)-induced increase in rearing behaviors was clearly inhibited by treatment with dynorphin A(1-13) (3.0 and 10.0 microgram). Simultaneously, the marked increases in linear locomotion and circling were displayed by apomorphine (1.0 mg/kg) plus dynorphin A(1-13) (10.0 microgram). The effects of dynorphin A(1-13) (10.0 microgram) on the apomorphine (1.0 mg/kg)-induced increase in rearing were entirely reversed by the opioid antagonist Mr2266. These results suggest that the antagonistic effects of dynorphin A(1-13) on the apomorphine (1.0 mg/kg)-induced increase in rearing are mediated via opioid receptors, possibly K-sites.
Ukai
M
M
Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Meijo University, Nagoya, Japan.
Toyoshi
T
T
Kameyama
T
T
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004399:Dynorphins / Q000494:pharmacology*; D007276:Injections, Intraventricular; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects*; D010446:Peptide Fragments / Q000494:pharmacology*
D010446:Peptide Fragments; C026843:dynorphin (1-13); D004399:Dynorphins; D001058:Apomorphine