奥曲肽对隐孢子虫感染后乳鼠空肠生长抑素受体4和5 mRNA表达的影响
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摘要
目的研究隐孢子虫感染乳鼠后,空肠生长抑素受体(somatostatin receptor,SSTR)4、SSTR5 mRNA表达的变化,及奥曲肽对感染后SSTR4、SSTR5 mRNA表达的影响。方法5日龄SD乳鼠灌胃给予隐孢子虫卵囊(10~9·L~(-1),每只0.1mL),在感染d 10~17腹腔注射奥曲肽(50μg·kg~(-1)·d~(-1)),对照组给予等量生理盐水。分别在感染后d 14、17、37、50取大鼠的空肠组织,免疫组化和real time-PCR法测定空肠SSTR4、SSTR5 mRNA水平。结果免疫组化结果显示,SSTR5主要表达在大鼠空肠黏膜下层,肠隐窝仅有少量表达,而SSTR4主要表达在肠隐窝,黏膜下层和吸收细胞少量表达。Real time-PCR结果显示,与未感染组相比,感染组SSTR4、SSTR5 mRNA表达均上调,奥曲肽使感染组SSTR4、SSTR5 mRNA表达降低。结论 SSTR4和SSTR5可能参与隐孢子虫感染后肠易激综合症的炎症反应,奥曲肽可能通过SSTR降低肠敏感性,缓解其症状。
Aim To investigate the effects of intestinal infection induced by Cryptosporidium parvum on the expression pattern of SSTR4 and SSTR5 subtype,and to examine the effect of octreotide on modulating shortterm and long-term SSTR4 and SSTR5 subtype expression in rat jejunum. Methods Five-day-old suckling Sprague-Dawley rats were orally gavaged with 105 Cryptosporidium oocysts to establish the model of post-infection irritable bowel syndrome( PI-IBS). Rats then received 50 μg·kg~(-1)·d~(-1) of octreotide by intraperitoneal injection from day 10 to day 17 post-infection.Animals were sacrificed on day 17,37 and 50 post-infection for immunohistochemical analysis and on day 14,35 and 50 for mRNA expression analysis of SSTR4 and SSTR5 subtypes. Results Immunohistological analysis of jejunum tissues demonstrated that SSTR5 was mainly expressed in submucosa while a little in crypt,while SSTR4 was mainly expressed in crypt while a little in submucosa and absorptive cells. Real-time PCR analysis indicated a significant increase of SSTR4 and SSTR5 expression in the inflamed jejunum. Octreotide treatment decreased the expression of SSTR4 and SSTR5 on day 50 post-infection. Conclusions SSTR4 and SSTR5 may be involved in the inflammatory reaction in PI-IBS rats induced by Cryptosporidium parvuman,which shows an increase in SSTR4 and SSTR5 mRNA expression in jejunum. Octreotide therapy inhibits the jejunum hypersensitivity and relieve PI-IBS symptoms,which may be related to the decrease of SSTR4 and SSTR5 expression.
Aim To investigate the effects of intestinal infection induced by Cryptosporidium parvum on the expression pattern of SSTR4 and SSTR5 subtype,and to examine the effect of octreotide on modulating shortterm and long-term SSTR4 and SSTR5 subtype expression in rat jejunum. Methods Five-day-old suckling Sprague-Dawley rats were orally gavaged with 105 Cryptosporidium oocysts to establish the model of post-infection irritable bowel syndrome( PI-IBS). Rats then received 50 μg·kg~(-1)·d~(-1) of octreotide by intraperitoneal injection from day 10 to day 17 post-infection.Animals were sacrificed on day 17,37 and 50 post-infection for immunohistochemical analysis and on day 14,35 and 50 for mRNA expression analysis of SSTR4 and SSTR5 subtypes. Results Immunohistological analysis of jejunum tissues demonstrated that SSTR5 was mainly expressed in submucosa while a little in crypt,while SSTR4 was mainly expressed in crypt while a little in submucosa and absorptive cells. Real-time PCR analysis indicated a significant increase of SSTR4 and SSTR5 expression in the inflamed jejunum. Octreotide treatment decreased the expression of SSTR4 and SSTR5 on day 50 post-infection. Conclusions SSTR4 and SSTR5 may be involved in the inflammatory reaction in PI-IBS rats induced by Cryptosporidium parvuman,which shows an increase in SSTR4 and SSTR5 mRNA expression in jejunum. Octreotide therapy inhibits the jejunum hypersensitivity and relieve PI-IBS symptoms,which may be related to the decrease of SSTR4 and SSTR5 expression.
引文
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[9]刘丽娜,周梁,田超,等.金荞麦总黄酮下调NR2B表达改善IBS大鼠痛觉过敏[J].中国药理学通报,2012,28(9):1289-93.[9]Liu L N,Zhou L,Tian C,et al.Improvement of IBS rats hyperalgesia by total flavones of Fagopyrum cymosum via down-regulation of NR2B expression[J].Chin Pharmacol Bull,2012,28(9):1289-93.
[10]刘雁冰,孙燕,刘菲.辣椒素受体TRPV1在大鼠内脏高敏感性发病机制中的作用[J].临床和实验医学杂志,2016,15(10):936-9.[10]Liu Y B,Sun Y,Liu F.The role of vanilloid receptor TRPV1 in visceral hypersensitivity in rat[J].J Clin Exp Med,2016,15(10):936-9.
[11]Szolcsányi J,Pintér E,Helyes Z,Petho G.Inhibition of the function of TRPV1-expressing nociceptive sensory neurons by somatostatin 4 receptor agonism:mechanism and therapeutical implications[J].Curr Top Med Chem,2011,11(17):2253-63.
[2]Hunter P R,Nichols G.Epidemiology and clinical features of Cryptosporidium infection in immunocompromised patients[J].Clin Microbiol Rev,2002,15:145-54.
[3]Khaldi S,Garqaia G,Le Goff L,et al.Cryptosporidium parvum isolate-dependent postinfectious jejunal hypersensitivity and mast cell accumulation in an immunocompetent rat model[J].Infect Immun,2009,77(11):5163-9.
[4]Bai J,Khaldi S,Garqaia G,et al.Effects of octreotide on jejunal hypersensitivity triggered by Cryptosporidium parvum intestinal infection in an immunocompetent suckling rat model[J].Neurogastroenterol Motil,2011,23(11):1043-50.
[5]马腾飞,王业秋,张宁,等.菝葜治疗便秘型肠易激综合征作用机制的实验研究[J].中国药理学通报,2012,28(1):109-14.[5]Ma T F,Wang Y Q,Zhang N,et al.An experimental study of Smilax treatment of constipation predominant irritable bowel syndrome and its mechanism[J].Chin Pharmacol Bull,2012,28(1):109-14.
[6]Rai U,Thrimawithana T R,Valery C,Young S A.Therapeutic uses of somatostatin and its analogues:current view and potential applications[J].Pharmacol Ther,2015,152(8):98-110.
[7]Krempels K,Hunyady B,O’Carroll A M,Mezey E.Distribution of somatostatin receptor messenger RNAs in the rat gastrointestinal tract[J].Gastroenterology,1997,112(6):1948-60.
[8]唐洪梅,房财富,廖小红,等.神经肽Y和5-羟色胺在腹泻型肠易激综合征模型大鼠中表达的研究[J].中国药理学通报,2012,28(7):916-20.[8]Tang H M,Fang C F,Liao X H,et al.Expression of NPY and 5-HT in rat model of diarrhea-predominant irritable bowel syndrome[J].Chin Pharmacol Bull,2012,28(7):916-20.
[9]刘丽娜,周梁,田超,等.金荞麦总黄酮下调NR2B表达改善IBS大鼠痛觉过敏[J].中国药理学通报,2012,28(9):1289-93.[9]Liu L N,Zhou L,Tian C,et al.Improvement of IBS rats hyperalgesia by total flavones of Fagopyrum cymosum via down-regulation of NR2B expression[J].Chin Pharmacol Bull,2012,28(9):1289-93.
[10]刘雁冰,孙燕,刘菲.辣椒素受体TRPV1在大鼠内脏高敏感性发病机制中的作用[J].临床和实验医学杂志,2016,15(10):936-9.[10]Liu Y B,Sun Y,Liu F.The role of vanilloid receptor TRPV1 in visceral hypersensitivity in rat[J].J Clin Exp Med,2016,15(10):936-9.
[11]Szolcsányi J,Pintér E,Helyes Z,Petho G.Inhibition of the function of TRPV1-expressing nociceptive sensory neurons by somatostatin 4 receptor agonism:mechanism and therapeutical implications[J].Curr Top Med Chem,2011,11(17):2253-63.