Effect Of Oubining On The Change Of SP And NK₁-R Induced By Cisplatin

OBJECTIVE Delayed vomiting is one of the most distressing side-effects of chemotherapy. Recently it is believed that substance P (SP) and its receptor, neurokinin receptor 1 (NK₁-R), play important roles in delayed vomiting, but the detail is not clear. So it is significant to study the function of SP and NK₁-R in vomiting and the preventing action of oubining, a decoction of Chinese medicine, on delayed vomiting induced by chemotherapy. Therefore the objective of this study is to detect the mechanism of oubining concerning on SP and NK₁-R. METHODS Fifty four rats were randomly divided into three groups: control group, model group and Chinese herbal group, 18 rats per group. The control group and model group were given saline via intragastric administration (i. g.), Chinese herbal group were given oubining via. i. g. twice a day, lasting to the evening before the rats were executed. The sixth day after i. g., the control group were given cisplatin (DDP) and the others were given saline via intraperitoneal injection (i.p.). 48 hours later, medulla oblongata and gastric antrum (GA) were taken out of rats. SP levels were measured with radioimmunoassay, and NK₁-R expression was detected by immunohistochemistry technique.RESULTS SP concentration in the medulla oblongata and GA of the model group is more than those of the control group (P<0.01 ) and Chinese herbal group (P<0.01 ), and there is no significance of SP concentrations between the herbal group and the control group (P>0. 05). The expression of NK₁-R in medulla oblongata and the mucosa of GA of the model group is stronger than the control group (P<0. 01 ) and the herbal group (P<0. 01 ), and there is no significance of NK₁-R expressions between the Chinese herbal group and the control group (P>0. 05).CONCLUSION (1)DDP increases SP levels in medulla oblongata and GA muscosa. (2)DDP enhance the expression of NK₁-R in medulla oblongata and the mucosa of GA . (3) oubining decreases SP levels in the medulla oblongata and GA muscosa induced by DDP. (4) oubining inhibits the strong expression of NK₁-R in medulla oblongata and GA mucosa induced by DDP.