Effects of naloxone infusion upon spontaneous and amphetamine-induced activity.
Naloxone-filled (1.0 mg/kg per h) or sham pumps were implanted subcutaneously (s.c.) in rats on day 0 and removed on day 7. Spontaneous locomotor activity was lower in naloxone-infused rats on day 3 only. Cumulative dose-response curves to D-amphetamine were constructed in separate groups on day 6 or day 8 (0.0-6.4 mg/kg s.c.). On day 6, naloxone infusion attenuated the gross movement response to D-amphetamine, but not the fine movement response. There were no differences in the response of naloxone- or sham-infused rats to D-amphetamine on day 8. Therefore, withdrawal from continuous naloxone infusion had no influence upon spontaneous or D-amphetamine-stimulated activity.
Jones
D N
DN
Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322.
Holtzman
S G
SG
D000818:Animals; D003913:Dextroamphetamine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D009270:Naloxone / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017450:Receptors, Opioid, mu / Q000187:drug effects
D017450:Receptors, Opioid, mu; D009270:Naloxone; D003913:Dextroamphetamine