Depression of pregabalin against acute tolerance of morphine in rats with chronic inflammatory pain / 中国临床药理学与治疗学

ABSTRACT

AIM: To investigate if pregabalin could depress the acute tolerance induced by morphine when curing the chronic inflammatory pain of rats.METHODS: 24 adult male Sprague-Dawley rats weighing 180-200 g were randomly divided into three groups(8 in each group).Freund's adjuvant was injected subcutaneously in left hind-paw of the rat to establish the chronic inflammatory pain model.3 days later,rats received 3 daily intragastrical(p.o.) morphine 8 mg/kg(M group),pregabalin 3 mg/kg(P group) or morphine 8 mg/kg+pregabalin 3 mg/kg(MP group) administrations respectively.The rats' pressure-withdrawal threshold(PWT) and paw withdrawal thermal latency(PWTL) were determined with Von-Frey hair test and rat hot-plate test respectively.The results of PWT and PWTL before and 15,30,60,120 min after medication were recorded.RESULTS: PWT and PWTL of the rats in M group increased after medication on all the time points of the first day and 15 min of the second day(P