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Orexin-A和阿瑞匹坦对顺铂诱发大鼠异食癖和摄食的影响研究
【作者】 张颖；
【导师】 徐珞；
【作者基本信息】 青岛大学 ， 病理学与病理生理学， 2016， 硕士
【摘要】 目的:观察食欲素(Orexin)和阿瑞匹坦对顺铂诱发大鼠异食癖的影响,并进一步探讨其可能的机制。方法:雄性Wistar大鼠随机分为对照组和顺铂处理组,顺铂处理组的大鼠,腹腔注射顺铂(3或6 mg/kg),对照组给予等量生理盐水。观察顺铂大鼠摄食高岭土量和食物摄入量的改变;免疫组化法观察顺铂对大鼠下丘脑弓状核(Arcuate nucleus,ARC)Orexin表达的影响;Real-time PCR法观察顺铂对大鼠下丘脑Orexin和延髓中P物质(Substance P,SP)前体-前速激肽原A(PPT-A)m RNA表达的影响;分别和联合应用SP受体(NK1受体)拮抗剂阿瑞匹坦和Orexin-A,观察其对顺铂大鼠异食癖和摄食量的影响。结果:腹腔注射3 mg/kg(低剂量组)顺铂,大鼠高岭土摄入量和摄食量与对照组相比无明显差异(P>0.05),而注射6 mg/kg(高剂量组)顺铂后,大鼠高岭土摄入量与对照组和低剂量组相比显著增加(P<0.05);高剂量顺铂组大鼠下丘脑ARC中Orexin表达显著减少(P>0.05);注射高剂量顺铂12 h时,大鼠延髓内PPT-A m RNA表达有轻微增加,但与对照组比较无统计学意义(P>0.05);但注射高剂量顺铂24 h后,延髓内PPT-A m RNA表达量显著增加(P<0.05)。在此后持续观察的5天中,顺铂可持续使延髓中PPT-A m RNA表达显著增高(P<0.05),在第5天时PPT-A m RNA仍维持在较高表达水平(P<0.05)。腹腔注射高剂量顺铂可显著抑制大鼠下丘脑Orexin m RNA表达,注射24 h时Orexin降低幅度最明显,为对照组的34.81±7.22%(P<0.05)。注射后的5天中,Orexin浓度均低于对照组(P<0.05);尾静脉注射阿瑞匹坦,大鼠高岭土摄入量显著减少(P<0.05),但摄食量无显著改变(P>0.05);侧脑室微量注射Orexin-A,大鼠高岭土摄入量明显减少(P<0.05),且摄食量显著增加(P<0.05);阿瑞匹坦和Orexin-A联合应用,可使顺铂大鼠异食癖和摄食量减少效应均显著减轻(P<0.05),且明显优于单纯阿瑞匹坦或Orexin-A应用(P<0.05)。提示,P物质和Orexin信号通路可能对顺铂化疗大鼠的异食癖和摄食量调控具有协同作用。结论:阿瑞匹坦和Orexin可减少顺铂化疗后大鼠的高岭土摄入量,而增加食物摄入量,该效应可能与P物质和Orexin信号通路激活有关。
【Abstract】 Objective:To observe the effect of substance SP and orexin on cisplatin induced pica in rat.Methods: Male Wistar rats were randomly divided into control group and cisplatin treatment group.The rats in the treatment group were treated with intraperitoneal injection of cisplatin(3 or 6 mg/kg),and the control group was given equal volume of normal saline.To observe the effect of rat kaolin consumptions and food intake changes;the expression of orexin in hypothalamus ARC by immunofluorescence histochemistry;Realtime PCR assay of cisplatin on orexin in hypothalamus and medulla of rats in SP precursor-preprotachykinin A(PPT-A)m RNA expression respectively;and combined application of SP receptor(NK1 receptor)antagonist aprepitant and orexin-A,observe its effect on cisplatin induced pica in rats and food intake.Results:Intraperitoneal injection of 3 mg/kg(low dose group)CIS PA,kaolin intake and food intake of rats compared with the control group had no significant difference(P > 0.05),and the injection of 6 mg/kg(high dose group)after cisplatin in rats,the kaolin intake compared with control group and low dose group increased significantly(P < 0.05);injection of high dose cisplatin 12 h,PPT-A m RNA expression in medulla of rats was increased slightly,but compared with the control group had no statistical significance(P > 0.05);but the injection of high dose cisplatin 24 h,PPT-A in medulla of m RNA expression was significantly increased(P < 0.05).During the 5 days of continuous observation,m RNA PPT-A expression was significantly higher(P < 0.05),and m RNA PPT-A remained at a relatively high level in fifth days(P < 0.05).Intraperitoneal injection of high dose of cisplatin significantly inhibited the expression of m RNA Orexin in hypothalamus of rats,the most significant reduction of Orexin in 24 h injection was 34.81 + 7.22%(P < 0.05)in control group.5 day after the injection,the concentration of Orexin was lower than the control group(P < 0.05);intraperitoneal injection of aprepitant in rats,kaolin intake significantly reduced(P < 0.05),but no significant change in food intake(P > 0.05);microinjection of Orexin-A into the lateral ventricle of rats significantly decreased(P kaolin intake < 0.05),and food intake increased significantly(P < 0.05);combined application of aprepitant and Orexin-A to cisplatin pica in rats and the effect of reduced food intake was significantly lower(P < 0.05),significantly better than pure aprepitant or Orexin-A(P < 0.05).Suggests that the P and Orexin signaling pathway may have synergistic effects on the regulation of the different eating habit and food intake in rats with cisplatin chemotherapy.Conclusions: Aprepitant and orexin can reduce kaolin intake and increase food intake in rats induced by cisplatin chemotherapy,the effect may be related to the activation of P and Orexin signaling pathway.