Differences of intensities regarding withdrawal signs in experimental methods For inducing morphine dependency

(Received 25 May, 2009 ; Accepted 10 August, 2009)AbstractBackground and purpose: In the present study, we compared the intensity of physical dependency, mortality rate and weight changes in some common methods for inducing morphine dependency.Materials and methods: Six common different methods for morphine dependency were chosen in wistar rats. In all methods, morphine dependency was induced by repeated morphine injection. Precipitation of morphine withdrawal signs were performed on the last day in each method, 4 hours after the last morphine injection for 20 minutes. The withdrawal signs included: vertical jumping, wet dog shakes, diarrhea, teeth chattering, ptosis, head shakes and rearing.Results: Our results demonstrated that all groups of treated rats showed withdrawal signs following naloxone challenge. However, the intensities of withdrawal signs (vertical jumping, wet dog shakes, diarrhea, teeth chattering, head shakes and rearing) were significantly different among these methods. Also, mortality rate and amount of weight loss were significantly different among the different methods.Conclusion: This study demonstrates that different experimental methods of morphine dependency can induce different intensities of withdrawal signs, mortality rate and weight loss. J Mazand Univ Med Sci 2009; 19(71): 20-26 (Persian

Short Communication Effect of trifluoperazine on carrageenan-induced acute inflammation in intact and adrenalectomized rats

Abstract: The aim of present study was to investigate the effect of trifluoperazine (TFP) on carrageenaninduced rat's paw edema in intact and adrenalectomized (ADX). TFP (0.2 and 8 mg/kg) were given intraperitoneally just before the intraplantar injection of 0.1 ml of 0.5% carrageenan solution. After four hours, paw edema was assessed by calculating the paw volume changes and extravasations of Evans blue dye as inflammatory indicators. In both ADX and control groups, administration of TFP reduced inflammatory parameters (paw volume and tissue content of Evans blue dye) in inflamed paw. Our findings suggest that TFP can effectively reduce carrageenan-induced paw edema in both ADX and control rats. Therefore, antiinflammatory effect of these drugs does not need the adrenal gland activity