Dissociation of tolerance to the analgesic and hypothermic effects of morphine by using thyrotropin releasing hormone |
| |
Authors: | H N Bhargava |
| |
Institution: | Department of Pharmacognosy and Pharmacology College of Pharmacy University of Illinois at the Medical Center Chicago, Illinois 60612, USA |
| |
Abstract: | The effects of thyrotropin releasing hormone (TRH) on tolerance to the analgesic and hypothermic effects of morphine were determined in male Swiss Webster mice. The tolerance to morphine was induced by SC implantation of a morphine pellet containing 75 mg morphine free base for 3 days. Subcutaneous injections of TRH (4 mg/kg) twice a day inhibited tolerance to the analgesic effect of morphine, as evidenced by a greater degree of analgesia in TRH treated mice as compared with similarly treated vehicle injected controls. The same treatment, however, failed to modify tolerance to the hypothermic effect of morphine. These effects were produced with alterations in brain or plasma levels of morphine. It is concluded that tolerance to the two pharmacological effects of morphine may involve separate mechanism. |
| |
Keywords: | |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|