Effects of taurine on tolerance to [D-Ala2, Met5]enkephalinamide in rats.
Effects of taurine on tolerance to [D-Ala2, Met5]enkephalinamide (DAME) were investigated in rats. Tolerance was produced by five intraventricular administrations of DAME (50 microgram) during 3 consecutive days. The magnitude of developed tolerance to DAME was not uniform for each behavioral parameter; tolerance to analgesia effects developed more intensively and rapidly from the repeated injections of the peptide than that to akinesia effects. Pretreatment with taurine (9.5 X 10(-2) M) which was injected in a volume of 10 microliter intraventricularly 10 min prior to every administration of DAME suppressed the development of tolerance to both analgesia and akinesia effects of this peptide, whereas pretreatment with L-leucine at the same concentration did not. Spontaneous locomotor activity was measured for 1 h after the 90-min behavioral observation period was completed. That activity increased with the number of the peptide injections. Taurine pretreatment inhibited the induction of 'hyper'-locomotor activity. These results support the view that taurine may possess an ability to inhibit development of tolerance to morphine-like peptides in rats.
D000698:Analgesia; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D004361:Drug Tolerance; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D013654:Taurine / Q000494:pharmacology*; D013997:Time Factors
D013654:Taurine; D004744:Enkephalin, Methionine; C022118:enkephalinamide-Met, Ala(2)-