The Effect Of The Compound Of Morphine And Lowdose Naloxone On Motilin In The Rat's Gastrointestinal Tract

ObjectiveMorphine is the commonly used analgesic. But it has some ill effects, such as; nausea, vomiting. Our departments investigations shown that the compound of morphine and low - dose naloxone would not decrease morphine s analgesia effect, and the compound could relieve the incidence of vomiting and nausea.Motilin is a major substance which cause gastrointestinal tracts contraction movement. Many drugs adjust the gastrointestinal tracts function by change the content of motilin. Is naloxone ameliorate the gastrointestinal tracts ill effects by change motilin?This study was designed to determine the effect of the compound of morphine and low - dose naloxone on motilin in the gastrointestinal tract and the analgesic effect of morphine.Methods51 Wistar rats suitability breeding 1 week, fasting 24h, prohibit water 12h before experiment. 5 rats had injury of nerve, 1 rats tube shedding remove from experiment.Intraperitoneal injection 0. 3ml/100g 10% chloral hydrate. Freeing the L1-2 interspace, exposuring the ligamenta flava, setting the tube and making the anterior extremity of tube at the level of L5₆. The volume of tube is 15μl. Anti-inflammation by intraperitoneal injection penicillin.30 male Wistar rats were allocated to six groups. The compound of mor-phine with different dose naloxne; morphine (1 group) , 5 μg/kg morphine with 0. 17ng/kg naloxone (2 group) , 5μg/kg morphine with 0. 8ng/kg naloxone (3 group) , 5μg/kg morphine with 1. 7ng/kg naloxone (4 group) , 5μg/kg morphine with 3.3ng/kg naloxone (5 group) was administered intraperitoneal. As-sesse the rats pain threshold before and 30 mins after medication. Determinate the suitable dose of naloxne in the compound.Another 15 male rats were allocated to 3 groups. 5 μg/kg morphine ( M group) , 5μg/kg morphine with 0. 17ng/kg naloxne ( M + N group) or saline (S group) were administered intraperitoneal. 2.5% formaldehyde solution was injected at the sole of left foot 30mins after medication. Motilin of plasm and gastrointestinal tract was measured 1 hours after drug injection.The data are expressed as mean values with standard deviation. Data were analyzed using one - way analysis of variance among groups, using T test within group. A P value < 0. 05 was considered statistically significant. Commercial software SPSS 11.0 (SPSS Inc. , Chicago, IL) for Windows was used for data processing.ResultThe pain threshold of 1 5 groups were identical ( P > 0. 05). The pain threshold of 1 3 groups after medication were longer than it before medication (P <0. 01) , the pain threshold of 4, 5 groups before medication were same as the pain threshold after medication ( P >0.05). And the pain threshold of 1, 2 groups after medication were longer than that of 3, 4, 5 groups ( P < 0. 01). The threshold of 3 group was longer than 4, 5 groups, shorter than 1, 2 groups(P<0.01)The suitable dose of naloxne in the compound was: morphine (5μg/kg) + naloxone (0. 17ng/kg).The content of motilin in plasm and colon were identical among three groups (P > 0.05). The content of motilin in body of stomach of M, M + N group was fewer than that of S groups (P<0.01; P<0.05). The content of motilin in antrum of stomach of M group was fewer than that of S and M + N groups ( P <...