Abstract
The ability of the selective cholecystokinin-B (CCK-B) receptor antagonist Cl 988 to reverse tolerance to morphine's antinociceptive effect was investigated with the hot-plate test in Sprague-Dawley rats. Tolerance was induced by subcutaneous (s.c.) injection of 10 mg kg-1 morphine twice daily for four days. On the fifth day rats were administered CI 988 (10 mg kg-1) or saline plus 5 mg kg-1 morphine s.c. Significant antinociception was observed in the group that received the CCK-B antagonist plus morphine, whereas the saline plus morphine group exhibited total tolerance. These results suggest that upregulation of the endogenous CCK system during repeated morphine administration may have an important role in the development of opiate tolerance.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
