Association of 5-hydroxytryptamine (serotonin) receptor 4 (5-HTR4) gene polymorphisms with asthma

Background and objective: The neurotransmitter, 5‐hydroxytryptamine, acts as an immunomodulator by stimulating the release of inflammatory cytokines and regulating the function of dendritic cells and monocytes. The 5‐hydroxytryptamine receptor 4 (HTR4) gene is located in a region previously linked to an increased risk of asthma and atopy. The aim of this study was to investigate the association between HTR4 and asthma. Methods: Thirty‐two single nucleotide polymorphisms (SNP) in HTR4 were investigated by direct sequencing of 24 DNA samples from unrelated Korean subjects. Results: The 32 genetic variants comprised 22 intronic SNP, two SNP in the 3′‐untranslated region (exon 7) and eight SNP in the 3′‐downstream region. Logistic regression analysis showed that two intronic polymorphisms were significantly associated with the risk of asthma. Two minor HTR4 alleles, +142828G > A and +122769G > A, occurred at significantly higher frequencies in the asthmatic group than in the healthy control group (49.59% vs 42.29%, P = 0.003, and 47.99% vs 40.35%, P = 0.008, respectively), and these differences remained significant after correction for multiple testing (P = 0.05, dominant mode of inheritance; and P = 0.03, dominant mode, respectively). Haplotype analysis revealed three haplotype blocks. The frequency of haplotype 1 in block 2 was significantly higher in asthmatics (P = 0.003, dominant mode), whereas the frequency of haplotype 4 in block 3 was significantly lower in asthmatics (P = 0.0009, dominant mode). Conclusions: SNP and haplotypes of the HTR4 gene were associated with the asthma phenotype and genetic variation of HTR4 may affect susceptibility to the development of asthma.     

Elevated concentration of 5–hydroxytryptamine in ultrafiltrate of human liver vein plasma after infusion of amino acids

Intragastric infusion of amino acids causes the release from the liver of a factor with stimulatory effect on smooth muscle. The effect of liver vein plasma ultrafiltrate was tested on isolated preparations of rat fundus. The ultrafiltrates collected after amino acid infusion had a 3–5 times higher stimulatory effect on smooth muscle contraction than those collected from control plasma. The active principle was isolated, purified by different chromatographic procedures and identified as 5–hydroxytryptamine (serotonin). No other compound with contractile effect on smooth muscle was detected.     

肠易激综合征患者肠黏膜5-羟色胺的表达及意义

目的检测肠易激综合征（IBS）患者肠黏膜5-羟色胺（5-HT）表达的差异,探讨外周5-HT在IBS发病中的作用。方法选择IBS腹泻型（D—IBS）21例、便秘型（C—IBS）22例患者及正常对照组19例,利用免疫组化方法检测各组回肠、近端结肠、远端结肠黏膜5-HT阳性细胞,计数阳性细胞数量并进行分析。结果D—IBS组回肠、近端结肠、远端结肠5-HT阳性细胞数显著多于对照组（P〈0．05）,并且回肠黏膜阳性细胞数也多于C—IBS组（P〈0．05）,C—IBS组回肠、近端结肠、远端结肠阳性细胞显著多于对照组（P〈0．05）。结论肠道5-HT的增加与IBS发病相关,IBS不同亚型发病机制可能与5-HT不同受体在中枢神经系统和消化道表达分布有一定关系。     

内脏高敏感大鼠腹腔肥大细胞活性的改变及5-羟色胺对其的作用

目的：证实内脏高敏感大鼠腹腔中肥大细胞活性增加，探讨5－羟色胺（5－HT）影响肥大细胞脱颗粒的作用。方法：用腹腔注射鸡卵清白蛋白制备内脏高敏感大鼠，并随机分为A组和B组；空白对照鼠（腹腔注射生理盐水）随机分为C组和D组。提取内脏高敏感大鼠和对照组大鼠的腹腔肥大细胞，用抗原和抗血清孵育刺激肥大细胞脱颗粒，计数肥大细胞脱颗粒率，并用荧光法检测其组胺释放率。比较经不含5－HT孵育液组（A组和D组）和富含5－HT孵育液组（B组和C组）孵育的肥大细胞脱颗粒率和组胺释放率。结果：内脏致敏组大鼠（A组和B组）的组胺释放率明显高于D组大鼠（P＜0．01），A组和B组的脱颗粒率也显著高于D组（P＜0．01）；且A组的组胺释放率显著高于B组（P＜0．05），C组和D组间组胺释放率未见明显差异。结论：内脏致敏大鼠的肥大细胞活性增强，5－HT对致敏肥大细胞的脱颗粒功能有影响。     

大鼠损伤皮肤组织5-羟色胺含量测定

为寻找生前损伤早期诊断指标，采用免疫散射浊度分析法，对生前、死后不同时间形成的大鼠切创皮肤的５ＨＴ进行对比分析。结果显示：生前损伤５分钟，５ＨＴ含量明显升高，１５分钟达高峰，６０分钟开始下降。生前损伤各组５ＨＴ含量均较自身对照组明显升高（升高４０％以上，Ｐ＜００５）；而死后５分钟和１５分钟组皮肤中５ＨＴ含量均较自身对照组升高（Ｐ＜００５），但增加幅度均低于３６％。提示，如创缘皮肤５ＨＴ含量比自身对照升高４０％，可判断为生前伤     

5—羟色胺对胃溃疡愈合的影响机理探讨

目的：探讨５－羟色胺及５－羟色胺受体阻断剂麦角新碱对大鼠实验性胃溃疡愈合的影响。方法；采用Ｏｋａｋａｒｓ改良法建立Ｗｉｓｔａｒ大鼠胃溃疡模型，分组腹膜腔注射５－羟色胺，麦角新碱，于给药后第１４天时间病理检查。结果：５－羟色胺组溃疡区炎症反应较重，毛细血管及成纤维细胞较少，麦角新碱组毛细血管床密度降低。两实验组溃疡面积、容积均大于盐水对照组。结论：外源性５－羟色胺及麦角新碱都不利于溃疡的愈合。     

5—羟色胺对大鼠新鲜分离背根神经节神经元膜电流的影响

应用全细胞膜片钳技术，观察５－羟色胺在大鼠新鲜分离背根神经节膜电流的影响，结果发现，在部分细胞（２４／４０），５－羟色胺（１０＾－４～１０＾－７ｍｏｌ／Ｌ）可引起浓度依赖性的同向电流，部分细胞（１２／４０），未检测到膜电流以的变化，部分细胞（４／４０）可引起微弱的外向电流，并就其可能机制进行了讨论。     

航天特定环境下抑郁症模型大鼠血清、海马及延髓中单胺神经递质含量变化

目的 研究航天特定环境下抑郁症模型大鼠血清、海马及延髓中单胺神经递质的变化.方法 选择旷场实验行为学评分相近的30只大鼠,按完全随机法分为对照组和模型组,每组15只.模型组采用经典抑郁症模型,结合航天特定环境,建立大鼠抑郁症模型,对照组不做任何处理.观察航天特定环境下抑郁症模型大鼠行为学变化,测定血清、海马、延髓组织中5-羟色胺(5-HT)、多巴胺(DA)及去甲肾上腺素(NE)含量的变化.结果 与对照组比较,造模后模型组大鼠旷场实验中的穿行格数和直立次数减少,理毛次数、中央格停留时间增加(均P＜0.05);模型组大鼠血清中5-HT、DA及NE含量均高于对照组[(334.23±110.45)μg/L比(248.76±51.83)μg/L,(109.19±26.86)μg/L比(88.42±12.63)μg/L,(102.46±39.31)μg/L比(74.88±12.04)μg/L,均P＜0.05)],而海马组织中NE含量低于对照组[(9.99±8.02)μg/L比(25.41±5.68)μg/L,P＜0.05].结论 航天抑郁症的产生可能与血清中5-HT、DA降低无关,而与海马组织中的NE降低有关.     

5‐HT2C receptor antagonists: Potential in schizophrenia

The therapeutic success of clozapine and other so‐called atypical antipsychotics has focused attention on the serotonin (5‐hydroxytryptamine; 5‐HT) system and its interaction with the dopaminergic system as a treatment for psychotic illnesses. Clozapine has been shown to display high affinity for the 5‐HT₂ receptor family and it has been suggested that this, together with evidence that dopamine D₂ receptor blockade following clozapine treatment is lower than typical antipsychotics, contributes to the therapeutic profile of clozapine and, in particular, its efficacy in treating the negative symptoms of schizophrenia. Much attention has concentrated on the interaction of clozapine and atypical antipsychotics with the 5‐HT_2A receptor. In this review, we focus on the role of the 5‐HT_2C receptor in both the therapeutic profile of atypical antipsychotics and in the regulation of the dopaminergic system. We further suggest that 5‐HT_2C receptor antagonists may have therapeutic utility in the treatment of psychotic illnesses. Drug Dev. Res. 54:88–94, 2001. © 2001 Wiley‐Liss, Inc.     

补肾活血方对血管性认知障碍模型大鼠神经递质及其受体的影响

目的观察补肾活血方对血管性认知障碍模型大鼠海马组织神经递质及其受体表达的影响。方法3月龄Wistar大鼠40只,采用双侧颈总动脉永久结扎法（2-VO）制作认知障碍模型大鼠,分别给予补肾活血方和银杏叶片15d。运用高效液相色谱法检测大鼠海马组织内乙酰胆碱（ACh）、5-羟色胺（5-HT）、多巴胺（DA）、谷氨酸（Glu）、甘氨酸（Gly）、γ-氨基丁酸（GABA）含量,免疫组化法检测其相应受体表达情况。结果与模型组相比,补肾活血方组中大鼠海马组织内ACh、5-HT、DA、GABA的含量及神经元中相应受体的表达均增高（P〈0．05或P〈0．01）,Glu、Gly的含量及神经元中相应受体的表达均降低（P〈0．05或P〈0．01）。结论补肾活血方可减轻神经元损伤导致的脑内ACh、5-HT、DA含量的减少,保护大脑学习记忆能力;其机制可能与其调节血管性认知障碍模型大鼠脑内兴奋性氨基酸（EAA）／抑制性氨基酸（IAA）平衡有关。