Pain-suppressed consumption of highly palatable liquid in rats.
Behav Pharmacol
; 35(5): 263-268, 2024 Aug 01.
Article
de En
| MEDLINE
| ID: mdl-38847464
ABSTRACT
This study determined whether consumption of a highly palatable liquid is a reliable measure of inflammatory pain and antinociception in male and female rats. After a 10-day acquisition period, the impact of intraplantar oil vs. complete Freund adjuvant (CFA) on consumption of vanilla-flavored Ensure was assessed, with a sipper tube height 12 or 19â
cm above the floor. CFA significantly decreased Ensure consumption, which completely recovered within 4-7 days to levels in oil-treated controls; neither sex nor sipper tube height significantly influenced Ensure consumption. CFA also significantly suppressed Ensure consumption in rats not exposed to the 10-day acquisition period, but only in males. To test the predictive validity of Ensure consumption as a measure of pain, separate rats were pretreated with a vehicle, an opioid, a nonsteroidal anti-inflammatory drug, or a cannabinoid the day after CFA treatment. Morphine and ibuprofen significantly attenuated CFA-suppressed drinking in at least one sex, and tetrahydrocannabinol did not. Neither ibuprofen nor tetrahydrocannabinol significantly altered drinking in oil-injected, 'pain-free' controls, but morphine increased drinking. These results demonstrate that CFA decreases consumption of a highly palatable liquid regardless of previous exposure (training) to the consumption procedure, but only in males. Although standard analgesics attenuate CFA-suppressed drinking, nonspecific hyperphagic effects can confound the interpretation of results. Thus, consumption of a highly palatable liquid is not an optimal measure for candidate analgesic screening.
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Douleur
/
Adjuvant Freund
Limites:
Animals
Langue:
En
Journal:
Behav Pharmacol
Sujet du journal:
CIENCIAS DO COMPORTAMENTO
/
FARMACOLOGIA
Année:
2024
Type de document:
Article
Pays d'affiliation:
États-Unis d'Amérique
Pays de publication:
Royaume-Uni