Seasonal variation of melatonin secretion across various segments of the gastrointestinal tract in rats

Objective:To investigate whether melatonin(MT)secretion in different parts of the gastrointestinal tract(GIT)exhibits seasonal variations and its correlation with immune regulation.Methods: Sixty Sprague-Dawley rats were divided into control and model groups,and the pineal gland was removed in the model group.Stomach,jejunum,ileum,and colon tissues were obtained during the spring equinox,summer solstice,beginning of autumn,autumn equinox,and winter solstice.The levels of MT,MT receptors(MR),arylalkylamine N-acetyltransferase(AANAT),hydroxyindole-O-methyltransferase(HIOMT),interleukin-2(IL-2),and interleukin-10(IL-10)in the GIT were measured using enzyme-linked immunosorbent assay.Results: Except for the stomach,the jejunum,ileum,and the colon showed seasonal tendencies in MT secretion.In the control group,MT secretion in the jejunum and ileum was the highest in the long summer,and colonic MT secretion was the highest in winter.In the model group,MT levels in the colon were highest in the summer.The seasonal rhythms of the MR,AANAT,HIOMT,IL-2,and IL-10 in the colon were roughly similar to those of MT,and changed accordingly after pinealectomy.Conclusions: Gastrointestinal MT secretion is related to seasonal changes,and MT secretion in each intestinal segment is influenced by different seasons.The biological effects of MT in the gut are inextricably linked to the mediation of MR,and a hormone-receptor linkage exists between MT and MR.The effect of seasonal changes on the gastrointestinal immune system may be mediated through the regulation of seasonal secretion of MT.

Malignant melanoma:An important differential diagnosis for clear cell sarcoma of the gastrointestinal tract

A case report by Liu et al describes the characteristics of metastatic clear cell sarcoma(CCS)of the pancreas and provides valuable therapeutic insights for this rare malignancy.This case is interesting because of its rarity,suggesting that the pancreas may be a potential target organ for CCS,either primary or metastatic.At the same time,the authors also emphasize the importance of regular postoperative follow-up for timely detection of recurrent lesions,as CCS is characterized by a high degree of malignancy and a high rate of recurrent metastases.Considering that CCS of the gastrointestinal tract is easily confused with malignant melanoma(MM)of the gastrointestinal tract,here we compare the clinical features,histopathological and immunohistochemical characteristics,diagnosis,treatment,and prognosis of CCS and MM of the gastrointestinal tract,hoping to provide a reference for clinical work.

Endoscopic resection for calcifying fibrous tumors of the gastrointestinal tract

BACKGROUND Calcifying fibrous tumors(CFTs)are rare mesenchymal lesions that can occur in various sites throughout the body,including the tubular gastrointestinal(GI)tract.AIM To analyze the clinical findings of 36 patients with GI tract CFTs to provide guidance for diagnosis and treatment.METHODS This retrospective study included 36 patients diagnosed with CFTs of the GI tract.We collected demographic and clinical information and conducted regular follow-ups to assess for local recurrence.RESULTS The stomach was the most commonly involved site,accounting for 72.2%of the 36 CFTs.Endoscopic mucosal resection(n=1,2.8%),endoscopic submucosal dissection(n=14,38.9%),endoscopic full-thickness resection(n=16,44.4%),and submucosal tunneling endoscopic resection(n=5,13.9%)were used to resect calcifying fibrous tumors.Overall,34(94.4%)CFTs underwent complete endoscopic resections with a mean procedure time of 39.8±29.8 min.The average maximum diameter of the tumors was 10.6±4.3 cm.No complications,such as bleeding or perforation,occurred during an average hospital stay of 2.9±1.2 d.In addition,two patients developed new growth of CFTs near the primary tumor sites,and none of the patients developed distant metastases during the follow-up period.CONCLUSION GI tract CFTs are rare and typically benign tumors that can be effectively managed with endoscopic procedures.

Prognostic value of T cell immunoglobulin and mucin-domain containing-3 expression in upper gastrointestinal tract tumors:A meta-analysis

BACKGROUND There is a lack of robust prognostic markers for upper gastrointestinal(GI)tract cancers,including esophageal,gastric,and esophagogastric junction cancers.T cell immunoglobulin and mucin-domain containing-3(TIM3)plays a key immunomodulatory role and is linked to the prognosis of various cancers.However,the significance of TIM3 in upper GI tract tumors is still uncertain.AIM To investigate the prognostic value of TIM3 expression in upper GI tract tumors.METHODS A literature search was conducted on the PubMed,Embase,and Web of Science databases for relevant studies published until June 2023.After screening and quality assessment,studies that met the criteria were included in the metaanalysis.Statistical methods were used for the pooled analysis to assess the association of TIM3 expression in upper GI tract tumors with the prognosis and clinicopathological parameters.The results were reported with the hazard ratio(HR)and 95%confidence interval(CI).RESULTS Nine studies involving 2556 patients with upper GI tract cancer were included.High TIM3 expression was associated with a worse prognosis in upper GI tract cancer(HR:1.17,95%CI:1.01-1.36).Positive expression of TIM3 in gastric cancer was correlated with the T and N stage,but the difference was not statistically significant.However,TIM3 overexpression was significantly correlated with the TNM stage(odds ratio:1.21,95%CI:0.63-2.33;P<0.05).TIM3 expression showed no association with the other clinicopathological parameters.CONCLUSION High expression of TIM3 in the upper GI tract cancer is associated with a worse prognosis and advanced T or N stages,indicating its potential value as a prognostic biomarker.These findings may provide a basis for the personalized treatment of upper GI tract cancers.

Efficacy of a Kiwifruit Extract (PhenActivTM) on Gastrointestinal Tract Function: A Randomised Double-Blind Placebo-Controlled Study

Objective: Gastrointestinal (GI) discomfort is experienced by millions of people every day. This study aimed to evaluate the effect of PhenActivTM, a novel green kiwifruit extract, on gastrointestinal tract (GIT) function in otherwise healthy adults. Methods: 41 healthy adults with mild GI discomfort were enrolled in this double-blind, randomized, placebo-controlled study. Participants were randomized to either take 3.0 g/day of PhenActivTM or a placebo for 6 weeks. Interviews were conducted at baseline, week 3 and week 6, with participants completing questionnaires regarding GI symptoms. Frequency of bowel movements was self-recorded daily. Results: There were no differences in daily and weekly defecation frequency and stool characteristics in either group. The active and placebo groups significantly improve GSRS scores (p , only the active group had a significant improvement in the IBSSS and PAC-QOL scores (p < 0.05) from baseline. Neither group had changes in sleep quality, quality of life and fatigue, plasma zonulin concentrations or macular pigment optical density scores. The product was well tolerated with no GI disturbances or adverse events being reported. Conclusion: Supplementation of 3.0 g/day of PhenActivTM for 6 weeks did not improve defecation frequency or stool composition in healthy adults, but did improve perceived symptoms of GIT function, including symptoms of functional GIT disorders, IBS and constipation. The product was well tolerated and future trials investigating higher doses with more participants and/or a different population would be beneficial.

Association of plant-based diets with the risk of upper gastrointestinal tract cancers:A systematic review and meta-analysis

Background:Diets rich in red or processed meat have been linked to an increased risk of cancers within the digestive system.It has been suggested that a plant-based diet may have protective effects against digestive system cancers.This study aimed to determine the association between plant-based diets and upper gastrointestinal tract cancers(UGTC).Methods:We conducted a systematic review and meta-analysis of observational studies.We searched the PubMed,Medline,Embase,and Web of Science databases for articles published up to September 30,2023.We pooled the risk ratios(RR)with the corresponding 95%confi-dence intervals(CI)using fixed or random-effects models.Results:Our meta-analysis included 16 studies(30 results).The data revealed a strong inverse association between a high intake of plant-based diets and UGTC(RR=0.60,95%CI=0.49-0.72),specifically gastric cancer(GC,RR=0.53,95%CI=0.42-0.67)and esophageal can-cer(EC,RR=0.63,95%CI=0.42-0.96).This relationship was not significant for gastric cardia cancer(GCA)or esophagogastric junctional cancer(EGJC,RR=0.76,95%CI=0.47-1.22).A subgroup analysis showed the association was significant in studies from Asia and Europe,as well as in studies utilizing indices such as a vegetarian diet,Mediterranean diet,the plant-based diet index,and principal component analy-sis(PCA)dietary patterns.There was no indication of publication bias among the analyzed studies.Conclusions:This meta-analysis highlights the potential health benefits of plant-based diets in preventing UGTC,particularly regarding esophageal squamous cell carcinoma(ESCC)and GC.Nevertheless,additional research is required to validate these results and explore the un-derlying mechanisms.

Optical coherence tomography in detection of dysplasia and cancer of the gastrointestinal tract and bilio-pancreatic ductal system

Optical coherence tomography(OCT) is an optical imaging modality that performs high-resolution,cross-sectional,subsurface tomographic imaging of the microstructure of tissues.The physical principle of OCT is similar to that of B-mode ultrasound imaging,except that it uses infrared light waves rather than acoustic waves.The in vivo resolution is 10-25 times better(about 10 μm) than with high-frequency ultrasound imaging,but the depth of penetration is limited to 1-3 mm,depending upon tissue structure,depth of focus of the probe used,and pressure applied to the tissue surface.In the last decade,OCT technology has evolved from an experimental laboratory tool to a new diagnostic imaging modality with a wide spectrum of clinical applications in medical practice,including the gastrointestinal(GI) tract and pancreatic-biliary ductal system.OCT imaging from the GI tract can be done in humans by using narrow-diameter,catheter-based probes that can be inserted through the accessory channel of either a conventional front-view endoscope,for investigating the epithelial structure of the GI tract,or a side-view endoscope,inside a standard transparent ERCP catheter,for investigating the pancreatico-biliary ductal system.Esophagus and the esophago-gastric junction has been the most widely investigated organ so far;more recently,also duodenum,colon and pancreatico-biliary ductal system have been extensively investigated.OCT imaging of the gastro-intestinal wall structure is characterized by a multiple-layer architecture that permits an accurate evaluation of the mucosa,lamina propria,muscularis mucosae,andpart of the submucosa.The technique may be,therefore,used to identify pre-neoplastic conditions of the GI tract,such as Barrett's epithelium and dysplasia,and evaluate the depth of penetration of early-stage neoplastic lesions.OCT imaging of the pancreatic and biliary ductal system could improve the diagnostic accuracy for ductal epithelial changes and the differential diagnosis between neoplastic and non-neoplastic lesions.

Abdominal tuberculosis of the gastrointestinal tract: Revisited

Abdominal tuberculosis is an increasingly common disease that poses diagnostic challenge,as the nonspecific features of the disease which may lead to diagnostic delays and development of complications.This condition is regarded as a great mimicker of other abdominal pathology.A high index of suspicion is an important factor in early diagnosis.Abdominal involvement mayoccur in the gastrointestinal tract,peritoneum,lymphnodes or solid viscera.Various investigative methods have been used to aid in the diagnosis of abdominal tuberculosis.Early diagnosis and initiation of antituberculous therapy and surgical treatment are essential to prevent morbidity and mortality.Most of the patients respond very well to standard antitubercular therapy and surgery is required only in a minority of cases.Imaging plays an important role in diagnosis of abdominal tuberculosis because early recognition of this condition is important.We reviewed our experience with the findings on various imaging modalities for diagnosis of this potentially treatable disease.

Connection between inflammation and carcinogenesis in gastrointestinal tract: Focus on TGF-β signaling

Inflammation is a primary defense process against various extracellular stimuli,such as viruses,pathogens,foods,and environmental pollutants.When cells respond to stimuli for short periods of time,it results in acute or physiological inflammation.However,if the stimulation is sustained for longer time or a pathological state occurs,it is known as chronic or pathological inflammation.Several studies have shown that tumorigenesis in the gastrointestinal (GI) tract is closely associated with chronic inflammation,for which abnormal cellular alterations that accompany chronic inflammation such as oxidative stresses,gene mutations,epigenetic changes,and inflammatory cytokines,are shared with carcinogenic processes,which forms a critical cross-link between chronic inflammation and carcinogenesis.Transforming growth factor (TGF)-β is a multi-potent cytokine that plays an important role in regulation of cell growth,apoptosis and differentiation.Most importantly,TGF-β is a strong anti-inflammatory cytokine that regulates the development of effector cells.TGF-β has a suppressive effect on carcinogenesis under normal conditions by inhibiting abnormal cell growth,but on the other hand,many GI cancers originate from uncontrolled cell growth and differentiation by genetic loss of TGF-β signaling molecules or perturbation of TGF-β adaptors.Once a tumor has developed,TGF-β exerts a promoting effect on the tumor itself and stromal cells to enhance cell growth,alter the responsiveness of tumor cells to stimulate invasion and metastasis,and inhibited immune surveillance.Therefore,novel development of therapeutic agents to inhibit TGF-β-induced progression of tumor and to retain its growth inhibitory activities,in addition to anti-inflammatory actions,could be useful in oncology.In this review,we discuss the role of TGF-β in inflammation and carcinogenesis of the GI tract related to abnormal TGF-β signaling.

CD74 in antigen presentation,inflammation,and cancers of the gastrointestinal tract

CD74 is a protein whose initial role in antigen presentation was recognized two decades ago. Recent studies have revealed that it has additional functions as a receptor for macrophage migration inhibitory factor and as a receptor for an important human pathogen, Helicobacter pylori （H pylon）. The role of CD74 as a receptor is important because after binding of migration inhibitory factor or H pylori, NF-κB and Erkl/2 activation occurs, along with the induction of proinflammatory cytokine secretion. This review provides an up-to-date account of the functions of CD74 and how it might be involved in inflammation and cancer within the gastrointestinal tract.

Multiple primary malignant tumors of upper gastrointestinal tract:A novel role of ^(18)F-FDG PET/CT

AIM: To evaluate the capacity of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for detecting multiple primary cancer of upper gastrointestinal (UGI) tract. METHODS: Fifteen patients (12 without cancer histories and 3 with histories of upper GI tract cancer) were investigated due to the suspicion of primary cancer of UGI tract on X-ray barium meal and CT scan. Subsequent whole body 18F-FDG PET/CT scan was carried out for initial staging or restaging. All the patients were fi nally confi rmed by endoscopic biopsy or surgery. The detection rate of multiple primary malignant cancers was calculated based on 18F-FDG PET/CT and endoscopic examinations.RESULTS: 18F-FDG PET/CT scan was positive in 32 suspicious lesions, 30/32 were true positive primary lesions, and 2/32 were false positive. In 15 suspicious lesions with negative 18F-FDG PET/CT scan, 12/15 were true negative and 3/15 were false negative. Among the 15 patients, 12 patients had 29 primary synchronous tumors confirmed by pathology, including 8 cases of esophageal cancers accompanied with gastric cancer and 4 of hypopharynx cancers with esophageal cancer. The other 3 patients had 4 new primary metachronous tumors, which were multiple primary esophageal cancers. PET/CT imaging detected local lymph node metastases in 11 patients. Both local lymph node metastases and distant metastases were detected in 4 patients. On a per-primary lesion basis, the sensitivity, specificity, accuracy, negative predictive value and positive predictive value of 18F-FDG PET/CT for detecting multiple primary cancer of UGI tract were 90.9%, 85.7%, 89.4%, 80% and 93.7%, respectively. CONCLUSION: The whole body 18F-FDG PET/CT may play an important role in evaluating the multiple primary malignant tumors of UGI tract cancer.

Mucosal lesions of the upper gastrointestinal tract in patients with ulcerative colitis:A review

Ulcerative colitis(UC)is a chronic,nonspecific,relapsing inflammatory bowel disease.The colorectum is considered the chief target organ of UC,whereas upper gastrointestinal(UGI)tract manifestations are infrequent.Recently,emerging evidence has suggested that UC presents complications in esophageal,stomachic,and duodenal mucosal injuries.However,UC-related UGI tract manifestations are varied and frequently silenced or concealed.Moreover,the endoscopic and microscopic characteristics of UGI tract complicated with UC are nonspecific.Therefore,UGI involvement may be ignored by many clinicians.In addition,no standard criteria have been established for patients with UC who should undergo fibrogastroduodenoscopy.Furthermore,specific treatment recommendations may be needed for patients with UC-associated UGI lesions.Herein,we review the esophageal,gastric,and duodenal mucosal lesions of the UC-associated UGI tract,as well as the potential pathogenesis and therapy.

Calcifying fibrous tumor of the gastrointestinal tract: A clinicopathologic review and update

Calcifying fibrous tumor(CFT)is a rare mesenchymal lesion that has been documented throughout the gastrointestinal tract.Gastrointestinal CFTs may occur at virtually any age,with a predilection for adults and for females.They occur most commonly in the stomach and the small and large intestines.CFTs are most often found incidentally,cured by local resection,and have a low risk of recurrence.Histology shows three characteristic features:Spindle cell proliferations within a densely hyalinized stroma,scattered calcifications,and lymphoplasmacytic inflammation.CFTs are immunoreactive for CD34,vimentin and factor XIIIa,helping to distinguish them from other benign mesenchymal neoplasms.The differential diagnosis of CFTs includes sclerosing gastrointestinal stromal tumor,leiomyoma,schwannoma,solitary fibrous tumor,inflammatory myofibroblastic tumor,plexiform fibromyxoma,fibromatosis,sclerosing mesenteritis,and reactive nodular fibrous pseudotumor.The pathogenesis of CFTs remains unclear,but some have hypothesized that they may be linked to IgG4-related disease,inflammatory myofibroblastic lesions,hyaline vascular type Castleman disease,sclerosing angiomatoid nodular transformation of the spleen,or trauma.

FoxO4 is the main forkhead transcriptional factor localized in the gastrointestinal tracts of pigs

Forkhead box （Fox） proteins play critical roles in the regulation of differentiation, proliferation, immunity and aging of cells. Most studies on Fox proteins are limited to cultured cells and rodent. The aim of the current study is to detect by immunohistrochemistry whether FoxO1, FoxO3a and FoxO4 proteins are localized in the stomach and intestine of the pig. The results showed that FoxO4 exists in the mucosa in all parts of the stomach and intestine; FoxO3a exists mainly in the lamina propria and muscularis of some parts. However, FoxOl is not detectable in all parts of the stomach and intestine. Collectively, the results of the present study indicate that there exists a distinct expression pattern of Fox proteins, and that FoxO4 is a primary forkhead transcriptional factor localized in the gastrointestinal tracts of the pig.

Optical coherence tomography and Doppler optical coherence tomography in the gastrointestinal tract

Optical coherence tomography(OCT) is a noninvasive,high-resolution,high-potential imaging method that has recently been introduced into medical investigations.A growing number of studies have used this technique in the field of gastroenterology in order to assist classical analyses.Lately,3D-imaging and Doppler capabilities have been developed in different configurations,which make this type of investigation more attractive.This paper reviews the principles and characteristics of OCT and Doppler-OCT in connection with analyses of the detection of normal and pathological structures,and with the possibility to investigate angiogenesis in the gastrointestinal tract.

Gastrointestinal tract distribution of Salmonella enteritidis in orally in fected mice with a species-specific fluorescent quantitative polymerase chain reaction

AIM: To identify and understand the regular distribution pattern and primary penetration site for Salmonella enteritidis (S. enteritidis) in the gastrointestinal tract. METHODS: Based on the species-specific DNA sequence of S. enteritidis from GenBank, a species-specific real- time, fluorescence-based quantitative polymerase chain reaction (FQ-PCR) was developed for the detection of S. enteritidis. We used this assay to detect genomic DNA of S. enteritidis in the gastrointestinal tract, including duodenum, jejunum, ileum, cecum, colon, rectum, esophagus and stomach, from mice after oral infection. RESULTS: S. enteritidis was consistently detected in all segments of the gastrointestinal tract. The jejunum and ileum were positive at 8 h post inoculation, and the final organ to show a positive result was the stomach at 18 h post inoculation. The copy number of S. enteritidis DNA in each tissue reached a peak at 24-36 h post inoculation, with the jejunum, ileum and cecum containing high concentrations of S. enteritidis, whereas the duodenum, colon, rectum, stomach and esophagus had low concentrations. S. enteritidis began to decrease and vanished at 2 d post inoculation, but it was still present up to 5 d post inoculation in the jejunum, ileum andcecum, without causing apparent symptoms. By 5 d post inoculation, the cecum had significantly higher numbers of S. enteritidis than any of the other areas (P < 0.01), and this appeared to reflect its function as a repository for S. enteritidis. CONCLUSION: The results provided significant data for clarifying the pathogenic mechanism of S. enteritidis in the gastrointestinal tract, and showed that the jejunum, ileum and cecum are the primary sites of invasion in normal mice after oral infection. This study will help to further understanding of the mechanisms of action of S. enteritidis.

Progastrin-releasing peptide and gastrin-releasing peptide receptor mRNA expression in non-tumor tissues of the human gastrointestinal tract

AIM： To investigate the expression of gastrin-releasing peptide （GRP） and GRP-receptor mRNA in non-tumor tissues of the human esophagus, gastrointestinal tract, pancreas and gallbladder using molecular biology techniques. METHODS： Poly A^＋ mRNA was isolated from total RNA extracts using an automated nucleic acid extractor and, subsequently, converted into single-stranded cDNA （sscDNA）. PCR amplifications were carried out using genespecific GRP and GRP-receptor primers. The specificity of the PCR amplicons was further confirmed by Southern blot analyses using gene-specific GRP and GRP-receptor hybridization probes. RESULTS： Expression of GRP and GRP-receptor mRNA was detected at various levels in nearly all segments of the non-tumor specimens analysed, except the gallbladder. In most of the biopsy specimens, coexpression of both GRP and GRP-receptor mRNA appeared to take place. However, expression of GRP mRNA was more prominent than was GRP-receptor mRNA. CONCLUSION： GRP and GRP-receptor mRNAs are expressed throughout the gastrointestinal tract and provides information for the future mapping and determination of its physiological importance in normal and tumor cells.

COVID-19 pandemic:Pathophysiology and manifestations from the gastrointestinal tract

The pandemic of coronavirus disease 2019(COVID-19),caused by a newly identifiedβ-coronavirus(SARS-CoV-2)has emerged as a dire health problem,causing a massive crisis for global health.Primary method of transmission was firstly thought to be animal to human transmission.However,it has been observed that the virus is transmitted from human to human via respiratory droplets.Interestingly,SARS-CoV-2 ribonucleic acid(RNA)has been isolated from patient stools,suggesting a possible gastrointestinal(GI)involvement.Most commonly reported clinical manifestations are fever,fatigue and dry cough.Interestingly,a small percentage of patients experience GI symptoms with the most common being anorexia,diarrhea,nausea and vomiting.The presence of viral RNA in stools is also common and fecal tests can be positive even after negative respiratory samples.The exact incidence of digestive symptoms is a matter of debate.The distribution of Angiotensin converting enzyme type 2 receptors in multiple organs in the body provides a possible explanation for the digestive symptoms’mechanism.Cases with solely GI symptoms have been reported in both adults and children.Viral RNA has also been detected in stool and blood samples,indicating the possibility of liver damage,which has been reported in COVID-19 patients.The presence of chronic liver disease appears to be a risk factor for severe complications and a poorer prognosis,however data from these cases is lacking.The aim of this review is firstly,to briefly update what is known about the origin and the transmission of SARS-CoV-2,but mainly to focus on the manifestations of the GI tract and their pathophysiological background,so that physicians on the one hand,not to underestimate or disregard digestive symptoms due to the small number of patients exhibiting exclusively this symptomatology and on the other,to have SARS-CoV-2 on their mind when the“gastroenteritis”type symptoms predominate.

Subcutaneous cervical emphysema and pneumomediastinum due to a lower gastrointestinal tract perforation

This case report describes a 69-year-old man presen-ting with an extensive subcutaneous emphysema in his neck and generalized peritonitis caused by a lower gastrointestinal tract perforation. This case emphasizes that subcutaneous emphysema patients with negative thoracic findings should be scrutinized for signs of retroperitoneal hollow viscus perforation.

Immunohistochemical study on distribution of endocrine cells in gastrointestinal tract of flower fish (Pseudophoxinus antalyae)

AIM： To detect distribution and relative frequency of endocrine cells in gastrointestinal tract of flower fish （Pseudophoxinus antalyae）. METHODS： The intestinal tract of flower fish was divided into four portions from proximal to distal; the enlarged area after oesophagus and anterior, middle and posterior intestine. Immunohistochemical method using the peroxidase anti-peroxidase complex was employed. All antisera between four portions of flower fish were compared using ANOVA. RESULTS： Eleven types of gut endocrine cells were determined; they were immunoreactive for calcitonin gene related peptide, substance P, vasoactive intestinal peptide, bombesin, somatostatin-14, secretin, TrkA, TrkB, TrkC, neurotensin, neuropeptide Y, which were found in almost all portions of the gastrointestinal tract. CONCLUSION： The regional frequency of immunoreactive distribution and relative cells in the flower fish, Pseudophoxinus antalyae, are essentially similar to those of other fish.