Journal article
Agonist/antagonist properties of nalbuphine, butorphanol and (-)-pentazocine in male vs. female rats
Pharmacology, biochemistry and behavior, Vol.75(1), pp.235-245
04/2003
Handle:
https://hdl.handle.net/2376/108861
PMID: 12759132
Abstract
To determine whether sex differences in the effects of mixed-action opioids could be due to differential activity at mu or kappa receptors, agonist/antagonist properties of nalbuphine, butorphanol and (-)-pentazocine were compared in male vs. female rats using a diuresis test. In water-loaded rats (2-h test), nalbuphine and (-)-pentazocine dose-dependently increased urination similarly in both sexes, whereas butorphanol increased urination more in females than in males on a ml/kg basis. The diuretic effects of all three opioids were at least partially blocked by the kappa receptor-selective antagonist nor-binaltorphimine (nor-BNI, 5 mg/kg) in both sexes. Kappa receptor-mediated antagonism of diuresis induced by U69,593 (0.56 mg/kg) was only observed with butorphanol in males. In water-loaded rats (1-h test), nalbuphine did not suppress, and butorphanol and (-)-pentazocine significantly suppressed urination in males only; all three mixed-action opioids dose-dependently blocked the antidiuretic effect of the selective mu agonist fentanyl (0.056 mg/kg) in both sexes. The ability of nalbuphine and (-)-pentazocine to block fentanyl-induced antidiuresis was not affected by pretreatment with nor-BNI in either sex. In contrast, the ability of butorphanol to block fentanyl-induced antidiuresis was attenuated by pretreatment with nor-BNI in males but not in females. These results suggest that sex differences in the effects of these mixed-action opioids are primarily due to their greater relative efficacy at the mu receptor in male than in female rats; butorphanol also may have greater efficacy at kappa receptors in females than in males.
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Details
- Title
- Agonist/antagonist properties of nalbuphine, butorphanol and (-)-pentazocine in male vs. female rats
- Creators
- R M Craft - Department of Psychology, Washington State University, CB 644820, Pullman, WA 99164-4820, USA. craft@wsu.eduD M McNiel
- Publication Details
- Pharmacology, biochemistry and behavior, Vol.75(1), pp.235-245
- Academic Unit
- Psychology, Department of
- Publisher
- United States
- Grant note
- DA 10284 / NIDA NIH HHS
- Identifiers
- 99900547156701842
- Language
- English
- Resource Type
- Journal article