Multi-dimensional analysis of behavior in mice treated with the delta opioid agonists DADL (D-Ala2-D-Leu5-enkephalin) and DPLPE (D-Pen2-L-Pen5-enkephalin).
The effects of intracerebroventricular injection of the delta-selective opioid peptides, DADL (D-Ala2-D-Leu5-enkephalin) and DPLPE (D-Pen2-L-Pen5-enkephalin), on spontaneous locomotor activity were investigated in mice using multi-dimensional behavioral analysis, based upon a capacitance system. The analysers classified the movements into 9 sizes (1/1, 1/2, 1/4, 1/8, 1/16, 1/32, 1/64, 1/128 and 1/256). Specific patterns of behavior were each registered on these sizes of movement. At 1.0 and 3.0 micrograms, DADL produced a significant increase in circling (1/4 size of movements) within 15 min after the start of measurements, while it produced a marked increase in linear locomotion (1/2 size), circling (1/4 size), rearing (1/16 size) and grooming (1/32, 1/64 and 1/128 sizes) within 15-30 min after the start. At 10.0 micrograms, DPLPE decreased linear locomotion (1/1 size) and conversely increased circling behavior (1/4 size) within 15 min after the start, whilst this peptide at 3.0 or 10.0 micrograms, produced a marked increase in linear locomotion (1/2 size), circling (1/4 size) and grooming (1/128 size) within 15-30 min after the start. The behavioral effects induced by DADL (3.0 micrograms) and DPLPE (10.0 micrograms) were completely reversed by naloxone (1.0 and 2.0 mg/kg). These results obtained with DPLPE, a delta-selective peptide and DADL, a less delta-selective peptide, indicate a common pattern of activity which was presumably delta receptor-mediated. However, one component (linear locomotion, at times immediately after administration of the peptide) did clearly differ between these two peptide analogues.(ABSTRACT TRUNCATED AT 250 WORDS)
Ukai
M
M
Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Meijo University, Nagoya, Japan.
Toyoshi
T
T
Kameyama
T
T
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D020881:Enkephalin, D-Penicillamine (2,5)-; D004743:Enkephalin, Leucine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D016308:Enkephalin, Leucine-2-Alanine; D004745:Enkephalins / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009043:Motor Activity / Q000187:drug effects; D009270:Naloxone / Q000494:pharmacology; D011957:Receptors, Opioid / Q000187:drug effects / Q000502:physiology*; D017465:Receptors, Opioid, delta
D004745:Enkephalins; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D009270:Naloxone; D004743:Enkephalin, Leucine; D016308:Enkephalin, Leucine-2-Alanine; D020881:Enkephalin, D-Penicillamine (2,5)-