Role of vasoactive intestinal peptide and nitric oxide in the modulation of electroacupucture on gastric motility in stressed rats

INTRODUCTION In recent years, along with the extensive research into enteric nerve system (ENS), increasing evidence shows that peptidergic neurotransmitters are the key factors regulating the gastric motility. Our previous research[1-3] showed that electroacupucture (EA) at acupoints of the Stomach Meridian of Foot-Yangmin may regulate gastric movement, increase blood flow in the microvessels in the gastric mucosa, and exert a protective effect on gastric mucosa. Nitric oxide (NO) an…     

Small intestinal bacteria overgrowth decreases small intestinal motility in the NASH rats

AIM： To explore the relationship between small intestinal motility and small intestinal bacteria overgrowth （SIBO） in Nonalcoholic steatohepatitis （NASH）, and to investigate the effect of SIBO on the pathogenesis of NASH in rats. The effect of cidomycin in alleviating severity of NASH is also studied.
METHODS： Forty eight rats were randomly divided into NASH group （n = 16）, cidomycin group （n = 16） and control group （n = 16）. Then each group were subdivided into small intestinal motility group （n = 8）, bacteria group （n = 8） respectively. A semi-solid colored marker was used for monitoring small intestinal transit. The proximal small intestine was harvested under sterile condition and processed for quantitation for aerobes （E. coli and anaerobes （Lactobacilli）. Liver pathologic score was calculated to qualify the severity of hepatitis. Serum ALT, AST levels were detected to evaluate the severity of hepatitis.
RESULTS： Small intestinal transit was inhibited in NASH group （P 〈 0.01）. Rats treated with cidomycin had higher small intestine transit rate than rats in NASH group （P 〈 0.01）. High fat diet resulted in quantitative alterations in the aerobes （E. coli） but not in the anoerobics （Lactobacill）. There was an increase in the number of E. coli in the proximal small intestinal flora in NASH group than in control group （1.70 ± 0.12 log10 （CFU/g） vs 1.28 ± 0.07 log10 （CFU/g）, P 〈 0.01）. TNF-α concentration was significantly higher in NASH group than in control group （1.13 ± 0.15 mmol/L vs 0.57 ± 0.09 mmol/L, P 〈 0.01）. TNF-α concentration was lower in cidomycin group than in NASH group （0.63 ± 0.09 mmol/L vs 1.13 ± 0.15 mmol/L, P 〈 0.01）. Treatment with cidomycin showed its effect by significantly lowering serum ALT, AST and TNF-α levels of NASH rats.
CONCLUSION： SIBO may decrease small intestinal movement in NASH rats. SIBO may be an important pathogenesis of Nash. And treatment with cidomycin by mouth can allevi     

Involvement of nitrergic neurons in colonic motility in a rat model of ulcerative colitis

BACKGROUNDThe mechanisms underlying gastrointestinal (GI) dysmotility with ulcerative colitis (UC) have not been fully elucidated. The enteric nervous system (ENS) plays an essential role in the GI motility. As a vital neurotransmitter in the ENS, the gas neurotransmitter nitric oxide (NO) may impact the colonic motility. In this study, dextran sulfate sodium (DSS)-induced UC rat model was used for investigating the effects of NO by examining the effects of rate-limiting enzyme nitric oxide synthase (NOS) changes on the colonic motility as well as the role of the ENS in the colonic motility during UC.AIMTo reveal the relationship between the effects of NOS expression changes in NOS-containing nitrergic neurons and the colonic motility in a rat UC model. METHODSMale rats (n = 8/each group) were randomly divided into a control (CG), a UC group (EG1), a UC + thrombin derived polypeptide 508 trifluoroacetic acid (TP508TFA; an NOS agonist) group (EG2), and a UC + NG-monomethyl-L-arginine monoacetate (L-NMMA; an NOS inhibitor) group (EG3). UC was induced by administering 5.5% DSS in drinking water without any other treatment (EG1), while the EG2 and EG3 were gavaged with TP508 TFA and L-NMMA, respectively. The disease activity index (DAI) and histological assessment were recorded for each group, whereas the changes in the proportion of colonic nitrergic neurons were counted using immunofluorescence histochemical staining, Western blot, and enzyme linked immunosorbent assay, respectively. In addition, the contractile tension changes in the circular and longitudinal muscles of the rat colon were investigated in vitro using an organ bath system. RESULTSThe proportion of NOS-positive neurons within the colonic myenteric plexus (MP), the relative expression of NOS, and the NOS concentration in serum and colonic tissues were significantly elevated in EG1, EG2, and EG3 compared with CG rats. In UC rats, stimulation with agonists and inhibitors led to variable degrees of increase or decrease for each indicator in the EG2 and EG3. When the rats in EGs developed UC, the mean contraction tension of the colonic smooth muscle detected in vitro was higher in the EG1, EG2, and EG3 than in the CG group. Compared with the EG1, the contraction amplitude and mean contraction tension of the circular and longitudinal muscles of the colon in the EG2 and EG3 were enhanced and attenuated, respectively. Thus, during UC, regulation of the expression of NOS within the MP improved the intestinal motility, thereby favoring the recovery of intestinal functions.CONCLUSIONIn UC rats, an increased number of nitrergic neurons in the colonic MP leads to the attenuation of colonic motor function. To intervene NOS activity might modulate the function of nitrergic neurons in the colonic MP and prevent colonic motor dysfunction. These results might provide clues for a novel approach to alleviate diarrhea symptoms of UC patients.     

非溃疡性消化不良患者胃窦壁内NO能,VIP能神经与胃排空关系的研究

目的探讨非溃疡性消化不良（NUD）患者胃运动障碍的发生机制。方法应用酶组织化学及免疫细胞化学方法结合图像分析系统对31例NUD患者（19例胃液体排空正常的患者为NUD1组和12例胃液体排空延迟的患者为NUD2组）及4例“正常”人胃窦壁内一氧化氮合酶（NOS，一氧化氮定位标志酶）、血管活性肠肽（VIP）进行了定位、定量研究。结果NUD2组患者胃窦粘膜肌内NOS、VIP阳性神经纤维比NUD1组、“正常”组明显增多、增粗，染色增强，粘膜下层易见到NOS阳性神经节细胞和丛内突起，NUD1组与“正常”组类似；NUD2组NO-S、VIP阳性神经的面积、平均吸光度值与NUD1组、“正常”组之间差异有显著性（P＜0．01）；胃液体半排空时间（T1／2）与三组NOS、VIP阳性神经的面积、平均吸光度值之间均有良好的相关性。结论胃液体排空延迟的NUD患者胃窦壁内NOS、VIP阳性神经纤维和末梢明显增多、活性增强。提示胃窦壁内NO能、VIP能抑制性神经异常改变在NUD患者的胃运动障碍中具有一定的作用。     

Role of nitric oxide in the impairment of circular muscle contractility of distended, uninflamed mid-colon in TNBS-induced acute distal colitis in rats

AIM: To evaluate the role of nitric oxide (NO) in the motor disorders of the dilated uninflamed mid-colon (DUMC) from trinitrobenzene sulfonic acid (TNBS)-induced acute distal colitis in rats. METHODS: Colitis was induced in male Sprague-Dawley rats by a single intracolonic administration of TNBS. Control rats received an enema of 0.9% saline. The rats were killed 48 h after TNBS or saline administration. Macroscopic and histologic lesions of the colon were evaluated. Myeloperoxidase (MPO) and nitric oxide synthase (NOS) activity were measured on the colonic tissue. In TNBS rats, we evaluated spontaneous and evoked contractile activity in circular muscle strips derived from DUMC in comparison to the same colonic segment of control rats, both in the presence and in the absence of a non-selective NOS isoforms inhibitor N-nitro-L-arginine (L-NNA). Pharmacological characterization of electric field stimulation (EFS)-evoked contractile responses was also performed. RESULTS: In TNBS rats, the distal colon showed severe histological lesions and a high MPO activity, while the DUMC exhibited normal histology and MPO activity. Constitutive NOS activity was similar in TNBS and control rats, whereas inducible NOS activity was significantly increased only in the injured distal colon of TNBS rats. Isometrically recorded mechanical activity of circular muscle strips from DUMC of TNBS rats showed a marked reduction of the force and frequency of spontaneous contractions compared to controls, as well as of the contractile responses to a contracting stimulus. In the presence of L-NNA, the contractile activity and responses displayed a significantly greater enhancement compared to controls. The pharmacological characterization of EFS contractile responses showed that a cooperative-like interaction between cholinergic muscarinic and tachykinergic neurokinin 1 and 2 receptors mediated transmission in DUMC of TNBS rats vs a simple additive interaction in controls. CONCLUSION: The results of this study show that, during TNBS-induced acute distal colitis, circular muscle intrinsic contractile mechanisms and possible enteric neural excitatory activity are inhibited in the distended uninfiamed mid-colon. Suppression of NO synthesis markedly improves spontaneous and evokes muscle contractions, in spite of any evident change in local NO activity.     

The effects of intestinal ischemia on colonic motility in conscious rats

Background  The present study aimed to examine whether and how colonic motility is affected by mild ischemia-induced intestinal injury in conscious rats through in vivo monitoring of colonic contractions, specifically with regard to the interstitial cells of Cajal (ICC) and the effect of nitric oxide (NO). Methods  Using miniature strain-gauge transducers, colonic motility with or without ischemia was recorded in conscious rats on the 4th, 7th, and 14th days after surgery. Histological examination for c-kit-positive cells was performed. Results  In control nonischemic rats, the number and duration of contractions (NC and DC, respectively) decreased gradually, but the mean amplitude of contractions (MC) and motility index (MI) did not change. On the 7th day, the NC in the ischemic group increased significantly when compared with that in the control group (P = 0.037). The DC in the ischemic group was lower than that in the control group; the difference was significant on the 4th day (P = 0.008). The MIs in the ischemic group were lower than those in the control group. In both groups, administration of NGnitro-l-arginine methyl ester on the 7th day increased only the resting cecal motility. Pathological examinations revealed c-kit-positive cells in both groups. Conclusions  Changes such as increased NC with shortened DC accompanied with decreased MI must have occurred at the ischemic site and might have been induced by an ischemic event. However, there exists a possibility that ICC and NO do not play a role in mild ischemia-induced dysmotility.     

Effects of psychological stress on small intestinal motility and bacteria and mucosa in mice

AIM: To investigate the effects of psychological stress on small intestinal motility and bacteria and mucosa in mice, and to explore the relationship between small intestinal dysfunction and small intestinal motility and bacteria and mucosa under psychological stress. METHODS: Sixty mice were randomly divided into psychological stress group and control group. Each group were subdivided into small intestinal motility group (n= 10), bacteria group (n = 10), and D-xylose administered to stomach group (n= 10). An animal model with psychological stress was established housing the mice with a hungry cat in separate layers of a two-layer cage. A semi-solid colored marker (carbon-ink) was used for monitoring small intestinal transit. The proximal small intestine was harvested under sterile condition and processed for quantitation for aerobes (Escherichia coli) and anaerobes (Lactobacilli). The quantitation of bacteria was expressed as Iog10(colony forming units/g). D-xylose levels in plasma were measured for estimating trie damage of small intestinal mucosa. RESULTS: Small intestinal transit was inhibited (39.80±9.50% vs 58.79±11.47%,P<0.01) in mice after psychological stress, compared with the controls. Psychological stress resulted in quantitative alterations in the aerobes (E.coli). There was an increase in the number of E coli in the proximal small intestinal flora (1.78±0.30 log10(CFU/g) vs 1.37±0.21 log10(CFU/g), P<0.01), and there was decrease in relative proportion of Lactobacilli and E.coli of stressed mice (0.53±0.63 vs 1.14±1.07,P<0.05), while there was no significant difference in the anaerobes (Lactobacilli) between the two groups (2.31±0.70 log10 (CFU/g) vs 2.44±0.37 log10(CFU/g), P>0.05). D-xylose concentrations in plasma in psychological stress mice were significantly higher than those in the control group (2.90±0.89 mmol/L vs 0.97±0.33 mmol/L, P<0.01). CONCLUSION: Small intestinal dysfunction under psychological stress may be related to the small intestinal motility disorder and dysbacteriosis and the damage of mucosa probably caused by psychological stress.     

Role of neuronal nitric oxide synthase and inducible nitric oxide synthase in intestinal injury in neonatal rats

AIM: To investigate the dynamic change and role of neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) in neonatal rat with intestinal injury and to define whether necrotizing enterocolitis (NEC) is associated with the levels of nitric oxide synthase (NOS) in the mucosa of the affected intestine tissue. METHODS: Wistar rats less than 24 h in age received an intraperitoneal injection with 5 mg/kg lipopolysaccharide (IPS). Ileum tissues were collected at 1, 3, 6, 12 and 24 h following LPS challenge for histological evaluation of NEC and for measurements of nNOS and iNOS. The correlation between the degree of intestinal injury and levels of NOS was determined. RESULTS: The LPS-injected pups showed a significant increase in injury scores versus the control. The expression of nNOS protein and mRNA was diminished after LPS injection. There was a negative significant correlation between the nNOS protein and the grade of median intestinal injury within 24 h. The expression of iNOS protein and mRNA was significantly increased in the peak of intestinal injury. CONCLUSION: nNOS and iNOS play different roles in LPS-induced intestinal injury. Caution should be exerted concerning potential therapeutic uses of NOS inhibitors in NEC.     

Effect of Helicobacter pylori infection on gastric mucosal pathologic change and level of nitric oxide and nitric oxide synthase

AIM: To investigate the level of nitric oxide (NO) and nitrous oxide synthase (NOS) enzyme and its effect on gastric mucosal pathologic change in patients infected with Helicobacter pylori(Hpylori), and to study the pathogenic mechanism of H pylori. METHODS: The mucosal tissues of gastric antrum were taken by endoscopy, then their pathology, H pylori and anti-CagA-IgG were determined. Fifty H pylori positive cases and 35 H pylori negative cases were randomly chosen. Serum level of NO and NOS was detected. RESULTS: One hundred and seven cases (71.33%) were anti-CagA-IgG positive in 150 H pylori positive cases. The positive rate was higher especially in those with pre-neoplastic diseases, such as atrophy, intestinal metaplasia and dysplasia. The level of NO and NOS in positive group was higher than that in negative group, and apparently lower in active gastritis than in pre-neoplastic diseases such as atrophy, intestinal metaplasia and dysplasia. CONCLUSION: H pylori is closely related with chronic gastric diseases, and type Ⅰ Hpylorimay be the real factor for H pylori-related gastric diseases. Infection with H pylori can induce elevation of NOS, which produces NO.     

内皮型一氧化氮合酶在早期糖尿病大鼠肾组织中表达的定量研究

目的探讨早期糖尿病大鼠肾组织内N0含量变化与一氧化氮合酶（eNOS）表达之间的关系。方法健康雄性SD大鼠60只随机分成糖尿病模型（DM）组和正常对照（NC）组,每组30只。检测两组大鼠的生化指标,检测肾皮质内NO的含量用亚硝酸还原酶法,肾皮质eNOS的含量用Western blot法。结果与同期NC组比较,（1）第1、2、4周DM组大鼠血糖显著升高（P〈0．01）;（2）DM组肾组织内NO含量在第1周时下降（3．52±0．45VS4．23±0．38）,P〈0．01;第2、4周时显著升高（P〈0．01）,第4周时升高最为明显（9．82±0．54VS4．02±0．32）,P〈0．01;（3）Western blot分析显示eNOS含量在第1周时下降,第2～4周时逐渐升高。结论早期糖尿病大鼠肾组织内NO含量逐渐升高,eNOS逐渐增多,提示在糖尿病早期肾组织内N0含量升高主要由eNOS增加引起。     

一氧化氮合酶和微血管生成与胃癌发展的关系

目的　研究诱导型一氧化氮合酶 (iNOS)在人胃癌组织中的表达及其与胃癌微血管形成、淋巴结转移及临床分期的关系。方法　采用免疫组化S P法检测 50例原发性胃癌组织、癌周组织及 2 0例正常胃黏膜组织中iNOS的表达 ,同时检测微血管密度 (MVD) ,以抗CD3 4标记血管内皮细胞 ,并分析其与肿瘤行为之间的关系。结果　 50例胃癌组织中iNOS阳性表达率为 70 .0 % ,MVD均值为 2 2 .0± 9 .8,显著高于癌周组织 (16.2 % ,6.1± 3 .4)和正常胃组织 (15.0 % ,5.5± 2 .6;P <0 .0 1)。按TNM分期 ,Ⅳ期胃癌组织iNOS阳性表达率为 93 .8% ,MVD为 42 .3± 3 .7,两者显著高于Ⅰ、Ⅱ、Ⅲ期 ,差异有显著性 (P <0 .0 1)。有淋巴结转移组iNOS的阳性表达率为 84.6% ,MVD均值为 2 7.4± 6.5;无淋巴结转移组iNOS阳性表达率为 54.2 % ,MVD均值为 15.3± 4.7,两组差异有显著性 (P <0 .0 5)。iNOS阳性表达组及高MVD值 (≥ 2 2 .0 )组的 3年生存率均显著低于iNOS阴性表达组及低MVD值 (<2 2 .0 )组 ,差异有显著性 (P <0 .0 5)。结论　胃癌组织中iNOS高阳性表达 ,随着iNOS阳性表达的增强 ,MVD值也增加 ,两者呈正相关。iNOS的表达及MVD与胃癌TNM分期、淋巴结转移及预后有密切关系。iNOS的表达及MVD值可作为判断胃癌预后的重要指标     

应激对大鼠结肠神经系统nNOS表达的影响

目的:探讨应激对大鼠结肠神经系统nNOS表达的影响. 方法:SD大鼠30只随机分为对照组,应激组和L-NAME 组,采用水浸-束缚应激(WRS)动物模型,用免疫组织化学ABC法检测nNOS在大鼠结肠黏膜下神经丛和肌间神经丛的表达,应用计算机图像分析系统对其表达进行定量分析．结果:与对照组比较,应激组黏膜下神经丛和肌间神经丛的nNOS阳性神经元的灰度值明显减少(P=0．02或P =0．005),阳性神经元细胞数的平均密度增加(P=0．04 或P=0．01),表达增强,且在黏膜上皮细胞、固有层淋巴细胞也有nNOS表达．L-NAME组黏膜下神经丛和肌间神经丛的nNOS阳性神经元的灰度值较应激组增加 (P=0．04),平均密度下降(P=0．04或P=0．03),表达减弱,而与对照组比较均无明显差异(P>0．05)．结论:应激可引起大鼠结肠神经系统nNOS表达增强, 提示一氧化氮(NO)在应激所致的结肠功能失调中可能起重要作用．     

老年大鼠大脑组织一氧化氮、一氧化氮合酶的变化及神经细胞凋亡研究

目的研究一氧化氮(NO)、一氧化氮合酶(NOS)在老年大鼠大脑中的变化及其与神经细胞凋亡的关系. 方法选用5月龄大鼠和30月龄大鼠,利用Griess反应和高压液相技术间接测量大脑NO水平和NOS活性;免疫组化和原位杂交技术分别检测神经元NOS(nNOS)蛋白质水平和nNOS、bcl-2基因水平;末端转移酶标记法原位检测大脑神经细胞凋亡状况. 结果老年大鼠大脑组织NO水平和nNOS活性分别是(2.61±0.10)μmol*L-1和(398.22±21.62)fmol*mg-1*min-1,显著高于青年大鼠的(1.54±0.15)μmol*L-1和(234.38±16.24)fmol*mg-1*min-1.老年大鼠大脑nNOS的基因水平和蛋白表达水平均升高,抗凋亡基因bcl-2水平降低.在老年大鼠大脑质皮检测到散在的凋亡细胞. 结论老年大鼠大脑组织NO水平升高是由于nNOS活性升高所致.nNOS活性的增高部分是由其基因和蛋白水平来决定的.老年大鼠大脑组织NO异常升高可能是导致神经组织损伤进而凋亡的原因之一.     

一氧化氮及其合酶在哮喘发病机制中的作用

探讨一氧化氮及其合酶在哮喘发病机制中的作用。方法 采用哮喘豚鼠模型，将豚鼠分为４组；１．哮喘组，用１０％卵白蛋白腹腔注射１ｍｌ致敏，２周后用１％卵白蛋白超声雾化吸入致其哮喘发作．２；肾上腺皮质激素预防组；诱喘同哮喘组，在每次诱喘前腹腔滴注地塞米松０．５ｍｇ／ｋｇ。３．硝基精氨酸甲酯预防组；诱喘同哮喘组，每次诱喘产腹腔注射ＬＮＮＡ０．４ｍｇ／ｋｇ。４．正常对照组；用生理盐水代替诱喘剂。每组分别测定其     

硝酸甘油治疗大鼠骨质疏松症血清NO、NOS的变化

目的初步探讨用硝酸甘油治疗骨质疏松症(OP)及其与一氧化氮(NO)、一氧化氮合酶(NOS)的关系。方法将40只6月龄雌性大鼠随机分成假手术组(15只)和OP模型组(25只),其中OP模型组去卵巢造成骨质疏松模型,从其中随机选5只大鼠测定血清NO、NOS的变化,并与5只假手术组大鼠比较。剩余OP模型组大鼠随机分为OP对照组(10只)与硝酸甘油治疗组(10只),硝酸甘油治疗组经硝酸甘油治疗骨密度升高后,测其血清NO、NOS的变化,并与OP对照组及假手术组比较。结果OP模型组血清NO、NOS低于假手术组(P<0.01,P<0.05)。硝酸甘油治疗组大鼠骨密度升高后,其血清NO、NOS高于OP对照组(P<0.01,P<0.05),而与假手术组差异无显著意义(P>0.05)。结论NO、NOS参与了骨质疏松症的病理生理过程,硝酸甘油治疗骨质疏松症可能与NO、NOS有关。     

不同年龄大鼠组织NO含量和NOS活性的变化与衰老之间的关系

目的探讨组织一氧化氮（ＮＯ）含量与一氧化氮合酶（ＮＯＳ）活性的变化规律,揭示其与衰老的关系。方法采用铜离子活化镉还原法、硫代巴比妥酸染色法和血红蛋白氧化测定组织ＮＯ、丙二醛（ＭＤＡ）含量和ＮＯＳ的活性。结果与青年鼠组（４－５月龄相比,老年鼠组（２０－２２月龄）心脑肾组织ＮＯ降低差异显著性（Ｐ〈０．０１）,而中年鼠组（９－１０月龄）仅肾组织ＮＯ含量降低有显著性差异（Ｐ〈０．０５）。中年鼠组比较,老年     

Association of gastric and intestinal phenotypic marker expression of gastric carcinomas with tumor thymidylate synthase expression and response to postoperative chemotherapy with 5-fluorouracil

Purpose It is well known that both gastric and intestinal phenotypic markers are expressed in gastric carcinomas, irrespective of their histological type. In the present study, the associations among phenotypic marker expression of gastric carcinomas, tumor thymidylate synthase (TS) expression, and the chemotherapeutic response to 5-fluorouracil (5-FU) were examined.Methods The gastric and intestinal phenotypic marker expression of the tumor was determined by the combination of the expression of human gastric mucin (HGM), MUC6, MUC2, and CD10, and was evaluated in comparison with tumor TS expression in 137 advanced gastric carcinomas in 137 patients (75 with postoperative chemotherapy with 5-FU and 62 without postoperative chemotherapy). Tumors were classified into the gastric- (G-), gastric and intestinal mixed- (GI-), intestinal- (I-), or unclassified- (UC-) phenotype according to the immunopositivity of HGM, MUC6, MUC2, and CD10 stainings. The associations among the gastric and intestinal phenotypic marker expression of the tumor, tumor TS expression, effect of postoperative chemotherapy with 5-FU, and the patients prognosis were examined.Results Of the 137 gastric carcinomas, 48 (35.0%), 58 (42.3%), 23 (16.8%), and 8 (5.8%)were classified as the G-, GI-, I- and UC-phenotype, respectively. The high TS expression of more than 25% tumor cell positivity was found in 25 (52.1%) of the 48 G-phenotype tumors, 39 (67.2%) of the 58 GI-phenotype tumors, 18 (78.3%) of the 23 I-phenotype tumors, and 4 (50.0%) of the 8 UC-phenotype tumors. The I-phenotype tumors were significantly correlated with the higher rate of the high TS expression as compared with the G-phenotype tumors (P<0.05). Among 48 patients with the G-phenotype tumor, the 5-year survival rate in patients with and without postoperative chemotherapy was 39.7 and 27.8%, respectively. The patients with postoperative chemotherapy had a significantly better prognosis than those without postoperative chemotherapy (P<0.05). Conversely, there were no significant correlations between the presence of postoperative chemotherapy and the patients prognosis among patients with GI-, I-, and UC-phenotype tumors.Conclusions These results indicate that postoperative chemotherapy with 5-FU could be effective for patients with the G-phenotype tumor, since the incidence of intratumoral expression of TS, the target enzyme of 5-FU, is significantly low in G-phenotype tumors.