Infliximab Inhibits Colitis Associated Cancer in Model Mice by Downregulating Genes Associated with Mast Cells and Decreasing Their Accumulation.

Inflammatory bowel diseases (IBDs), such as Crohn's disease or ulcerative colitis, can be treated with anti TNF-alpha (TNF-α) antibodies (Abs), but they also put patients with IBDs at risk of cancer. We aimed to determine whether the anti TNF-α Ab induces colon cancer development in vitro and in vivo, and to identify the genes involved in colitis-associated cancer. We found that TNF-α (50 ng/mL) inhibited the proliferation, migration, and invasion of HCT8 and COLO205 colon cancer cell lines and that anti TNF-α Ab neutralized TNF-α inhibition in vitro. The effects of anti TNF-α Ab, infliximab (10 mg/kg) were investigated in mouse models of colitis-associated cancer induced by intraperitoneally injected azoxymethane (AOM: 10 mg/kg)/orally administered dextran sodium sulfate (DSS: 2.5%) (AOM/DSS) in vivo. Infliximab significantly attenuated the development of colon cancer in these mice. Microarray analyses and RT-qPCR revealed that mast cell protease 1, mast cell protease 2, and chymase 1 were up-regulated in cancer tissue of AOM/DSS mice; however, those mast cell related genes were downregulated in cancer tissue of AOM/DSS mice with infliximab. These results suggested that mast cells play a pivotal role in the development of cancer associated with colitis in AOM/DSS mice.

Novel Potent ABCB1 Modulator, Phenethylisoquinoline Alkaloid, Reverses Multidrug Resistance in Cancer Cell.

ATP-binding cassette (ABC) transporters, which are concerned with the efflux of anticancer drugs from cancer cells, have a pivotal role in multidrug resistance (MDR). In particular, ABCB1 is a well-known ABC transporter that develops MDR in many cancer cells. Some ABCB1 modulators can reverse ABCB1-mediated MDR; however, no modulators with clinical efficacy have been approved. The aim of this study was to identify novel ABCB1 modulators by using high-throughput screening. Of the 5861 compounds stored at Tohoku University, 13 compounds were selected after the primary screening via a fluorescent plate reader-based calcein acetoxymethylester (AM) efflux assay. These 13 compounds were validated in a flow cytometry-based calcein AM efflux assay. Two isoquinoline derivatives were identified as novel ABCB1 inhibitors, one of which was a phenethylisoquinoline alkaloid, (±)-7-benzyloxy-1-(3-benzyloxy-4-methoxyphenethyl)-1,2,3,4-tetrahydro-6-methoxy-2-methylisoquinoline oxalate. The compound, a phenethylisoquinoline alkaloid, was subsequently evaluated in the cytotoxicity assay and shown to significantly enhance the reversal of ABCB1-mediated MDR. In addition, the compound activated the ABCB1-mediated ATP hydrolysis and inhibited the photolabeling of ABCB1 with [125I]-iodoarylazidoprazosin. Furthermore, the compound also reversed the resistance to paclitaxel without increasing the toxicity in the ABCB1-overexpressing KB-V1 cell xenograft model. Overall, we concluded that the newly identified phenethylisoquinoline alkaloid reversed ABCB1-mediated MDR through direct interaction with the substrate-binding site of ABCB1. These findings may contribute to the development of more potent and less toxic ABCB1 modulators, which could overcome ABCB1-mediated MDR.

Lymph nodes around the posterior gastric artery: their existence, frequency, and clinical implications.

PURPOSE: The lymphatic flow along the posterior gastric artery (PGA) is considered of possible clinical importance in terms of lymphatic metastasis; however, little is known about the lymph nodes (LNs) around this artery. The purpose of this study was to establish if LNs exist around the PGA and to evaluate their clinical implications. METHODS: We examined the tissues surrounding the PGA from 21 cadavers to search for LNs. We also investigated the patterns of lymphatic metastases in patients who underwent surgery for gastric neoplasms at our institute to detect their presence along the PGA. RESULTS: The PGA was identified in 11 cadavers, and LNs around the PGA were detected microscopically in 2 of these. Lymphatic metastasis directly to the LNs at the splenic artery without any metastases was regarded as skip metastasis along the PGA. Skip metastasis was found in two of ten patients who underwent surgery for remnant gastric cancer. CONCLUSIONS: The existence of LNs around the PGA was confirmed, and based on our findings, lymphatic metastasis through the PGA is possible in patients with remnant gastric cancer.

[Endoscopy-Assisted Partial Duodenal Resection for Duodenal Adenoma in a Patient with Familial Adenomatous Polyposis].

We here report a case of endoscopy-assisted partial duodenal resection for duodenal adenoma in a patient with familial adenomatous polyposis(FAP). A male underwent total proctocolectomy with ileal pouch anal anastomosis in 1997. Since 2004, duodenal adenomas occurred and the atypical grade of adenoma was gradually aggravated. Therefore, he underwent endoscopy-assisted partial duodenal resection in 2013. The pathological finding of the specimen showed well-differentiated tubular adenocarcinoma(pM, ly0, v0). No recurrence has been observed at 4 years after the operation. Endoscopy-assisted partial duodenal resection was minimum invasive surgery and considered to be useful for the patients with duodenal adenoma.

Frey's procedure for chronic pancreatitis improves the nutritional status of these patients.

PURPOSE: The aim of surgical intervention for chronic pancreatitis (CP) is to relieve symptoms and improve quality of life. However, the precise effect of surgery on the nutritional status of CP patients, which is often impaired by exocrine and endocrine pancreatic dysfunction, has not been elucidated. We conducted this study to evaluate whether Frey's procedure improves the nutritional status of CP patients. METHODS: The nutritional status of 35 patients who underwent Frey's procedure for CP at our institute between April 2005 and December 2014, was assessed by the controlling nutritional status (CONUT) scoring before and 1 year after the surgery, and compared with that of seven CP patients who underwent pancreatoduodenectomy. The occurrence of postoperative hepatic steatosis was also monitored. RESULTS: The nutritional status improved after Frey's procedure, but not after pancreatoduodenectomy. The median postoperative CONUT score after Frey's procedure was significantly lower than the preoperative score (1.0 ± 0.5 vs. 4.0 ± 2.5; p < 0.001). CONCLUSION: Frey's procedure is superior to pancreatoduodenectomy for improving the nutritional status of CP patients.

Synthetic Analogs of Curcumin Modulate the Function of Multidrug Resistance-Linked ATP-Binding Cassette Transporter ABCG2.

Multidrug resistance (MDR) caused by the overexpression of ATP-binding cassette (ABC) transporters in cancer cells is a major obstacle in cancer chemotherapy. Previous studies have shown that curcumin, a natural product and a dietary constituent of turmeric, inhibits the function of MDR-related ABC transporters, including ABCB1, ABCC1, and especially ABCG2. However, the limited bioavailability of curcumin prevents its use for modulation of the function of these transporters in the clinical setting. In this study, we investigated the effects of 24 synthetic curcumin analogs with increased bioavailability on the transport function of ABCG2. The screening of the 24 synthetic analogs by means of flow cytometry revealed that four of the curcumin analogs (GO-Y030, GO-Y078, GO-Y168, and GO-Y172) significantly inhibited the efflux of the ABCG2 substrates, mitoxantrone and pheophorbide A, from ABCG2-overexpressing K562/breast cancer resistance protein (BCRP) cells. Biochemical analyses showed that GO-Y030, GO-Y078, and GO-Y172 stimulated the ATPase activity of ABCG2 at nanomolar concentrations and inhibited the photolabeling of ABCG2 with iodoarylazidoprazosin, suggesting that these analogs interact with the substrate-binding sites of ABCG2. In addition, when used in cytotoxicity assays, GO-Y030 and GO-Y078 were found to improve the sensitivity of the anticancer drug, SN-38, in K562/BCRP cells. Taken together, these results suggest that nontoxic synthetic curcumin analogs with increased bioavailability, especially GO-Y030 and GO-Y078, inhibit the function of ABCG2 by directly interacting at the substrate-binding site. These synthetic curcumin analogs could therefore be developed as potent modulators to overcome ABCG2-mediated MDR in cancer cells.

[Surgical Training Utilizing Swine Under General Anesthesia and Animal Ethics].

A cross-sectional study is conducted with primary residents attended wet labs at Tohoku University Hospital Advanced Medical Training Center in order to investigate the efficacy of the training, especially focused on the animal ethics. The 41 participants answered questionnaires in regard to non-technical skills, technical skills and ethics before and after the practice. To identify differences in each ethical question between 2 time points, Wilcoxon signed ranks test was used because the data was not normally distributed. As the result of it, all animal ethical questions showed significant differences(0.0016≤p≤0.0380, α=0.05 level of significance). Beside them, only 1 out of 5 general ethical questions showed it (p=0.0137). This outcome verified that the lecture of animal ethics and the observation of animal care in this center fixed in the training curriculum clearly induced participants' psychological movements.

Genotyping Analysis of Bitter-Taste Receptor Genes TAS2R38 and TAS2R46 in Japanese Patients with Gastrointestinal Cancers.

Type-2 bitter-taste receptors (TAS2Rs) are important for the evaluation of food quality and the nutritional control in animals. Mutations in some TAS2Rs including TAS2R38 are known to increase susceptibility to various diseases. However, the involvement of TAS2Rs in cancers has not been well understood. We conducted a pilot study by genotyping two TAS2R genes, TAS2R38 and TAS2R46, in Japanese cancer patients diagnosed with the following types of cancer: biliary tract cancer, hepatocellular carcinoma, pancreatic cancer, colorectal cancer and gastric cancer. We selected the two TAS2Rs because they carry virtually non-functional alleles in human populations. We found that cancer risk is not associated with any TAS2R46 genotypes since there were no significant differences in genotype frequencies between cancer patients and controls. On the other hand, we confirmed that phenylthiocarbamide (PTC) non-tasters homozygous (AVI/AVI) for TAS2R38 were more frequent among Japanese cancer patients than those among controls as suggested in a previous study. The AVI/AVI genotype was therefore considered to increases cancer risk. In contrast, we also found that homozygous (PAV/PAV) PTC tasters are less frequent among cancer patients, suggesting that the PAV/PAV is a cancer resistant genotype that decreases cancer risk. Genotype frequencies for heterozygous AVI/PAV genotype were not significantly different between the two groups. It is suggested that the risk and resistance of cancers is antagonistically controlled by the two TAS2R38 alleles, PAV and AVI, rather than by the AVI allele alone.

Oral rehydration solution normalizes plasma renin and aldosterone levels in patients with ulcerative colitis after proctocolectomy.

OBJECTIVES: The possible effects and benefits of oral rehydration solution (ORS) on chronic dehydration after total proctocolectomy. METHODS: To evaluate the effect of ORS on the renin-angiotensin system after remnant proctocolectomy in patients with ulcerative colitis (UC), we selected 20 patients after remnant proctocolectomy, ileal J pouch-anal anastomosis, and construction of a diverting ileostomy for UC. Patients were randomly divided into two groups, A (n=9) or B (n=11), 2 weeks after the surgery. In group A, ORS (1000 mL/day) was given for the first 7 days and mineral water (1000 mL/day) for the next 7 days. In group B, mineral water (1000 mL/day) was given for the first 7 days and ORS (1000 mL/day) for next 7 days. Plasma levels of renin, aldosterone and excretion of sodium in urine were evaluated at days 0, 7, and 14. We defined day 0 as the day of beginning this study. RESULTS: Mean plasma renin levels on day 0 were six to eight times greater than the upper normal limit. In group A, ORS lowered plasma renin levels. In group B, plasma levels of renin and aldosterone after ORS were lower than those at days 0 and 7. CONCLUSIONS: ORS corrected increased plasma levels of renin and aldosterone to within the normal range in patients after proctocolectomy.

[Multidisciplinary Treatment for Squamous Cell Carcinoma of the Anal Canal].

Chemoradiotherapy(CRT)has been recognized as a standard treatment for locoregional squamous cell carcinoma of the anal canal in Western countries. However, surgery had historically been considered as a standard treatment and there are only a few reports on CRT for anal canal cancer in Japan. In this study, we analyzed medical records of 5 anal canal cancer patients treated with CRT in our hospital between 2005 and 2015. Patients' characteristics were as follows: median age, 70 years (range 42-80 years); male/female, 1/4; and clinical Stage I / III a/ III b, 3/1/1. The regimens of chemotherapy were MMC plus 5-FU in 4 patients and CDDP in 1 patient. The median follow-up period was 30 months(range, 6 to 100 months). After CRT, 4 patients achieved complete response. The other patient with partial response underwent salvage surgery. All patients were alive without recurrence. In conclusion, our retrospective study showed that CRT is considered to be a standard treat- ment for anal canal cancer.

[A Case of Undifferentiated Carcinoma of the Sigmoid Colon That Responded to Paclitaxel and Carboplatin Chemotherapy].

We report a case of a 72-year-old woman who was initially diagnosed with ovarian cancer with peritoneal carcinomatosis. Systemic chemotherapy consisting of paclitaxel and carboplatin(TC)was administered. Although a partial response(PR)was achieved after the 4 courses of TC, this regimen was discontinued due to severe adverse events. Ten months after discontinuation of TC, because abdominal CT and colonoscopy showed an intra-tumoral abscess caused by invasion of the tumor to the sigmoid colon, abdominal total hysterectomy, bilateral salpingo-oophorectomy, and a Hartmann's operation were performed to control the disease symptoms. Pathological examination revealed that the tumor was an undifferentiated carcinoma of the sigmoid colon. This case report suggests that the TC regimen may be effective for treating undifferentiated carcinoma of the colon.

Gastrointestinal toxicities of 5-fluorouracil increase the proportion of regulatory T cells in intestinal tract: advantages of alternate-day S-1 administration.

BACKGROUND: 5-Fluorouracil (5-FU), a core anticancer agent for malignancies, induces gastrointestinal (GI) toxicities. Despite recent advances in tumor immunology, it still remains unknown how GI toxicities affect antitumor immunity. S-1 is a tegafur-based oral 5-FU prodrug which has been widely introduced in Japan and other countries. The alternate-day S-1 administration has been proposed to minimize its GI and other toxicities without reducing its anticancer efficacy. METHODS: In this study, two S-1 administration regimens were compared in mice to evaluate their impact of GI toxicities on immunity. In the daily group as a standard administration model, S-1 was administered for 14 days on and 14 days off, and in the alternate-day group as a non-GI toxicity model, S-1 was administered every other day for 28 days. As well as physical findings, regulatory T cells, Th1 cells and other cells in murine lymphoid tissues were analyzed with flow cytometry. RESULTS: Only the daily group exhibited body weight loss and GI toxicities. In the daily group, a proportion of regulatory T cells in the intestinal lymphoid tissue were demonstrated to be six-fold higher than in the control without S-1, and the proportion of Th1 cells showed a decreasing trend. However, the alternate-day group exhibited almost no change in T-cell subsets. CONCLUSION: GI toxicities of 5-FU may have a negative influence on antitumor immunity due to increased proportions of regulatory T cells and decreased proportions of Th1 cells. The alternate-day S-1 administration may be a useful regimen with its minimal influence on T-cell subsets.

[Total Pelvic Exenteration for Local Recurrence of Rectal Cancer Appearing 12 Years after Curative Operation--A Case Report].

A 49-year-old man had undergone Hartmann's operation for rectal cancer in August 2002. The disease stage (TNM 7th) was T3, N1, M0, Stage ⅢB. He was treated with UFT and Krestin for a year as adjuvant chemotherapy. No recurrence had been detected after the surgery. In July 2014, he presented with symptoms of acute renal failure. A CT scan showed bilateral hydronephrosis and a pelvic tumor between the urinary bladder and rectum. The pathological diagnosis based on biopsy specimens was adenocarcinoma. Because immunostaining studies of the tumor biopsy specimen revealed that CK20, CEA, CA19-9, and p53 were positive and CK7 and PSA were negative, this pelvic tumor was diagnosed as a local recurrence of rectal cancer. Total pelvic exenteration and ileal conduit urinary diversion were carried out for the recurrent tumor with curative intent. The reported recurrence rate of Stage Ⅲ colorectal cancer 5 years after the initial curative operation is 0.67%. Local recurrence of rectal cancer 12 years after the initial operation is quite rare. Immunostaining is helpful to discriminate between rectal cancer and a tumor of the urinary organs. It is important to consider that recurrence of rectal cancer might still occur a long time after the initial operation.

Usefulness of alternate-day administration of S-1 and leucovorin in a xenograft mouse model of colorectal cancer: a shorter drug-free interval leads to more efficient antitumor effects.

BACKGROUND: A clinical trial of S-1 with leucovorin (S-1/LV) in metastatic colorectal cancer (CRC) patients demonstrated promising efficacy; however, the gastrointestinal toxicities were so severe that it has not been applied in the clinical setting. On the other hand, alternate-day administration of S-1 has been proposed to attenuate the adverse events without reducing its anticancer activity. Our present study was conducted to confirm the feasibility of alternate-day administration of S-1/LV in in vivo xenograft tumor models. METHODS: Mice were treated with S-1/LV in a daily group (2 weeks of administration followed by 2 weeks of withdrawal) or an alternate-day group (administration on alternate days for 4 weeks), then the mice were killed and the xenograft tumors were resected. We compared body weight changes, condition of feces, mucosal injury and myelosuppression and assessed adverse reactions, tumor volume, tumor growth inhibition (TGI) and expression of Ki67, TUNEL, cIAP2 and XIAP to evaluate the antitumor activity and tumor apoptosis. RESULTS: Severe weight loss, diarrhea, mucosal injury and myelosuppression were observed only in the daily group; however, some myelosuppression was also observed in the alternate-day group. The TGI in the alternate-day group was better than in the daily group, possibly resulting from apoptosis due to the suppression of cIAP2 but not XIAP. CONCLUSION: Our findings suggest that alternate-day administration of S-1/LV for CRC treatment can achieve high antitumor activity without severe adverse reactions, and we propose that clinical trials with this regimen should be conducted in CRC patients.

The best surgical approach for perforated gastric cancer: one-stage vs. two-stage gastrectomy.

BACKGROUND: Surgery for perforated gastric cancer has a dual purpose: treating life-threatening peritonitis and curing gastric cancer. An emergent one-stage gastrectomy may place an undue burden on patients with a poor general status and could impair long-term survival even if the gastric malignancy is curable. A two-stage gastrectomy, in which the initial treatment of peritonitis is followed by elective gastrectomy, can accomplish both desired purposes. METHODS: We retrospectively analyzed 514 Japanese cases of perforated gastric cancer. 376 patients underwent a one-stage gastrectomy and 54 patients underwent a two-stage gastrectomy. We evaluated patient characteristics, surgical outcomes, postoperative complications, and survival rates in both groups. RESULTS: The two-stage gastrectomy group saw a 78.4% rate of curative R0 resection and 1.9% hospital mortality rate, while corresponding rates in the one-stage gastrectomy group were 50 and 11.4%, respectively. Among cases in which curative R0 resection was performed, there was no significant difference in overall survival between 136 one-stage gastrostomies and 40 two-stage gastrostomies. In a multivariate analysis, curative R0 resection [hazard ratio (HR) 2.937, p = 0.001] and depth of tumor invasion (HR 1.179, p = 0.016) were identified as independent prognostic factors. CONCLUSIONS: Regardless of whether patients underwent a one-stage or two-stage gastrectomy, curative R0 resection improved survival in patients with perforated gastric cancer. When curative R0 resection cannot be performed in the initial treatment phase due to diffuse peritonitis, non-curative and palliative gastrectomy should be avoided, and a two-stage gastrectomy should be planned following peritonitis recovery and detailed examinations.

[A case of pathological complete response to lt. Lateral lymph node metastasis from lower rectal cancer by S-1 combined neoadjuvant chemoradiotherapy].

A 54-year-old man presented with an enlarged left (lt) lateral lymph node (LLN), which was detected by magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET-CT). Endoscopic examination of the colon revealed the presence of a type 1 tumor, 20mm in diameter, in the lower rectum; the tumor was diagnosed as a well-differentiated adenocarcinoma (tub1). The patient received combined neoadjuvant chemoradiotherapy (nCRT)with S- 1 for treatment of the rectal cancer and LLN metastasis (MP, T2N3M0, Stage IIIb). S-1 was administered orally at a dose of 120 mg/day on days 1-14, and 22-35; a total dose of 45 Gy was delivered (1.8 Gy/day, for 25 days). Upon nCRT, there was a remarkable reduction in the tumor size, the primary tumor receded, and the LLN decreased from 16 mm to 8 mm in diameter. The maximum standardized uptake value (SUVmax) also decreased from 3.8 to 1.9 on PET-CT. Six weeks after nCRT, ultralow anterior resection and bilateral lymph node dissections were performed. Histopathological examination showed a partial presence of cancer cells in the scarred primary tumor; however, no viable cancer cells were observed in the lt. LLN.

Duodenal switch for intractable reflux gastroesophagitis after proximal gastrectomy.

Reflux gastroesophagitis is a common postgastrectomy complication after proximal gastrectomy, and conservative treatments including protease inhibitors and proton pump inhibitors are effective in most patients. Here we report a patient with severe reflux gastroesophagitis after proximal gastrectomy, in whom surgical treatment of duodenal switch was effective. An 80-year-old man complained of intractable heartburn, anorexia, and body weight loss after having undergone proximal gastrectomy, with reconstruction by esophagogastrostomy with valvuloplasty and pyloroplasty, for early gastric cancer 14 months before referral to our department. Oral administration of protease inhibitors and proton pump inhibitors was ineffective. Laboratory evaluation showed poor nutritional status. On endoscopic examination, we noted the redness, bleeding, and multiple erosions in the esophagus and the gastric remnant. He was diagnosed to have severe gastroesophagitis due to reflux of duodenal juice into the gastric remnant and esophagus. We performed duodenal switch to divert duodenal juice from the gastric remnant and esophagus; the duodenum was transected 2 cm distal to the pylorus, the duodenal distal end was closed, and a 50-cm Roux limb from the proximal jejunum was anastomosed to the proximal end of the duodenum. The heartburn disappeared postoperatively, and endoscopic examination revealed marked improvement of the reflux gastroesophagitis. One year postoperatively, the patient is free from symptoms including heartburn. His body weight increased, and laboratory data showed improvement in nutritional status. In conclusion, the duodenal switch may be surgical treatment of choice for intractable reflux gastroesophagitis after proximal gastrectomy.

[Therapeutic strategy for neuroendocrine tumor of the rectum].

The clinicopathological features of neuroendocrine tumor (NET) of the rectum were retrospectively analyzed in 25 patients( 17 men and 8 women; mean age, 57 years[ 30-78 years]) at Tohoku University Hospital from January 1998 to December 2012. The average diameter of 25 tumors was 15 mm (5-70 mm). Local resections and rectal resections with lymph node dissection were performed in 16 and 9 tumors, respectively. Three of the 9 tumors had lymph node metastases (33%), including 2 tumors with a diameter of 10 mm. In a median follow-up of 48 months, tumor recurrence was observed in 3 of 25 patients( 12%); local recurrence was observed in 1 patient; and liver metastasis was observed in 2 patients. Of the 2 patients with liver metastasis, liver metastasis recurred in a patient whose primary tumor, with a diameter of 10 mm, had been locally resected 40 months ago. According to histopathological analysis, 3 primary tumors with local recurrence or liver metastasis were categorized as G2 or G3 according to the World Health Organization (WHO) classification. Tumors with a diameter of ≥10 mm, in principle, may be removed by rectal resection with lymph node dissection. However, histopathological findings such as a proliferation of tumor cells should also be taken into consideration when deciding the treatment strategy for rectal NET.

The effect of a total colectomy on the motor inhibition of the upper gut induced by intraileal stimuli in conscious dogs.

PURPOSE: The administration of stimuli to the ileum inhibits upper gastrointestinal motility. The aim of this study was to determine whether a total colectomy can alter this motor inhibitory effect. METHODS: Beagle dogs were each equipped with four strain gauge force transducers on the upper gastrointestinal tract. The infusion of nutrients (saline as placebo control, oleate, butyrate, and glucose) began 90 min after feeding and continued for 30 min via a silicone catheter placed in the ileal lumen. Capsaicin (10 mg) was injected into the ileum as a bolus. All of the dogs underwent a relaparotomy and a total colectomy, and the same experiments were performed on all dogs. RESULTS: Before performing a colectomy, the oleate, the glucose, and the capsaicin were each found to inhibit the postprandial upper gastrointestinal motility in comparison to the placebo control (P < 0.05). The butyrate had no inhibitory effect. After a total colectomy, the inhibition of upper gastrointestinal motility was observed after the intraileal infusion of the oleate and the capsaicin (P < 0.05). The motor inhibitory response to the intraileal glucose was delayed after a total colectomy, and a reduction of the motility index was not observed in the gastric antrum and the duodenum because of this delay. However, a significant reduction in the motility index was observed in the jejunum. CONCLUSION: The intraileal stimuli-induced motor inhibition decreased after a total colectomy after the administration of glucose, but not after the administration of either oleate or capsaicin.

The effect of growth hormone releasing peptide-2 on upper gastrointestinal contractile activity and food intake in conscious dogs.

BACKGROUND: The aim of this study was to evaluate the effect of growth hormone releasing peptide (GHRP)-2, a synthetic ligand for the growth hormone secretagogue receptor, on upper gastrointestinal motility and food intake. METHODS: Five neurally intact dogs and five dogs with vagotomy and pyloroplasty were equipped with strain gauge force transducers on the stomach, duodenum and jejunum. GHRP-2 (0.5-10 microg/kg) was administered intravenously in neurally intact dogs in the interdigestive state and after feeding. To study the mechanism of GHRP-2-induced inhibition on postprandial contractions, various antagonists were administered intravenously prior to GHRP-2. The effect of GHRP-2 on postprandial contractions was also studied in dogs with vagotomy. GHRP-2 was also administered immediately before feeding in each group, and its effect on food intake was assessed. RESULTS: GHRP-2 did not evoke gastrointestinal contractions in the interdigestive state. GHRP-2 induced contractile inhibition continuing for 2-3 min in neurally intact dogs and dogs with vagotomy. This inhibitory effect was reversed by the alpha- and alpha(2)-blockers. GHRP-2 increased food intake in neurally intact dogs, but not in dogs with vagotomy. CONCLUSIONS: These results indicate that in the upper gut GHRP-2 inhibits postprandial contractions via alpha(2)-receptors on the enteric nervous system, whereas an intact vagal nerve is necessary for a GHRP-2-induced increase in food intake.