The effect of the resin (amberlite) on gastric emptying scintigraphy

.4.818 AGA ABSTRACTS • G3358 IDENTIFICATION AND CHARACTERIZATION OF INTRINSIC SENSORY NEURONS OF THE SUBMUCOSAL PLEXUS. H. Pan and M. D. Gershon, Dept. Anatomy & Cell Biology, Columbia University P&S, New York, NY 10032. Mucosal enterochromaffin cells appear to be sensory transducers that use 5-HT to stimulate the mucosal processes of intrinsic and extrinsic sensory neurons. The intrinsic sensory neurons synapse with other intrinsic neurons to drive peristaltic and secretory reflexes. We have proposed that intrinsic sensory neurons of the submucosal plexus are cholinergic and that at least a subset of them may also contain calcitonin gene relented peptide (CGRP). We have also suggested that the 5-HTle receptor activates intrinsic sensory axons, which explains why 5-HT3 antagonists can be used to treat nausea without blocking intrinsic neural reflexes. In the current study, we confirm that submucosal sensory neurons a r e excited by 5-HT1p receptors and we show that both acetycholine and CGRP are critical for neurotransmission from submucosal primary afferents. Studies were carried out with an isolated preparation of submucosa, containing an island of intact mucosa. Intracellular recordings with Neurobiotin-filled electrodes permitted impaled neurons to be visualized. Following stimulation of the mucosa with puffs of N 2, stroking, 5-HT, or Way 100325 (a 5-HT w agonist) fast and/or slow EPSPs were recorded in submucosal neurons. All EPSPs were abolished by 5-HTP-DP, a 5-HT1p antagonist. Fast EPSPs were blocked by hexamethonium (C6), while slow EPSPs were abolished by atropine or a CGRP antagonist (CGRPs.37), DiI was used to label neurites at the site of stimulation. The Neurobiotin-filled neurons from which recordings were obtained were contacted by DiI-labled axons. The latency of C6-sensitive fast EPSPs (7.3 a 0.6 ms), elicited by delivering focal electrical shocks to the mucosa, was relatively constant. The mucosal stimuli thus monosynaptically activate impaled neurons. Additional studies examined the spread of neuronal excitation within the submucosal plexus following mucosal stimulation with N 2 puffs or stroking. Excited neurons were visualized "on-line" with FM2-10 fluorescence or they were identified subsequently by demonstrating Fos immunoreactivity. Following treatment with CGRPs..~7, very few stimulated neurons could be located by either technique. These studies support the hypothesis that submucosal sensory neurons are cholinergic/CGRP-containing cells that are activated by 5-HT1v receptors. Supported by NIH grant NS 12969. G3359 BENEFICIAL EFFECT OF DROTAVERINE IN IRRITABILE BOWEL SYNDROME (IBS). A. Pan. J. Hamvas, I. Filiczky, M. Burai, 2nd Dept. Med., St. Imre Hospital, Budapest; E. Szikszay, Chinoin, Budapest, Hungary. Irritable bowel syndrome (IBS) is a benign disorder that affects up to 20% of adults through their lives. Not a single study has been published that provides compelling evidence of therapeutic efficacy of any drugs in IBS but some smooth-muscle relaxants showed 27% and 19% improvements over placebo in global assessment and pain, respectively. Drotaverine (No-Spa, Chinoin, Budapest) inhibits smooth mucle contractions by changing intracellular Ca distribution and by an inhibitory action on phosphodiesterase increasing intercellular cAMP levels. In a double blind, randomized, placebo control study, we enrolled 62 patients (53 females, 9 males, mean age 50.8 :e 14.2 years) with IBS and constipation into 2 groups. They recorded their complaints daily during 2 weeks pretreatment period, and during 8 weeks of treatment with 3x2 tablets (3x80mg) of Drotaverine (30 pts) or 3x2 tbl of placebo (32 pts). Fourteen patients dropped from the study at least partially. Abdominal pain, stool frequency, bloating or distention and dyspepsia were recorded and scored. Colon transit time was also measured with radioopaque markers before and at the end of treatment. The active treatment significantly reduced the abdominal pain by 47% while in the placebo group severity of pain increased by 3%. Also bloating somewhat, although not significantly diminished by No-Spa but dyspepsia and constipation did not change. According to the opinion of the patients and physicians the active treatment was effective in 15/24 and 17/24 cases, respectively but the placebo seemed to be also beneficial in 12/25 patients. No significant adverse effect was observed during the treatment period. Conclusion: Drotaverine can effectively diminish abdominal pain and bloating in IBS but the placebo effect of treatment is as high as 48%. Erzsrbet Szikszay, Employee Chinoin, Budapest, Hungary • G3360 THE EFFECT OF THE RESIN (AMBERLITE) ON GASTRIC EMPTYING SCINTIGRAPHY. HC Park*, CW Song, CD Kim, HS Ryu, JG Choi*., JH Hyun. Dept. of Internal Medicine, Chung Ang Gil Hospital*, Inchon, Institute of Digestive and Nutrition, and Nuclear MedicineS,, Korea University Hospital, Seoul, Korea. Radioisotopic scintigraphy has become a 'gold standard' for studying gastric emptying. Although the measurement of solid emptying is more sensitive than that of liquid emptying in detection of underlying pathophysiology, no standard method has yet been developed. Aims: The aims of the study are to investigate the effect of resin(amberlite) and its mechanism on gastric solid emptying. Methods: Twenty eight healthy volunteers were enrolled in the study. Gastric emptying scintigraphy using dual head gamma-camera were measured twice in each subject. The 500 cal balanced test meal mixed with

GASTROENTEROLOGY Vol. 114, No. 4 the labeled resin(amberlite RIA-410, Sigma)(resin + group), and the same test meal without the resin(resin - group) were given randomly with one week interval. In vitro study, gastric juice mixed with the same test meal was separated into fluid and solid components by the centrifuge and the percentage of free technetium within the liquid component were measured. Results: Gastric half emptying time(Tl/2) in resin(+) group was significantly delayed than resin(-) group(p<0.001), which were 89.4 ± 17.6 rain and 72.1 ± 17.1 min, respectively. Two hour retention rates in the resin(+) group was significantly higher than the resin(-) group(p<0.001), which were 38,3 _+ 13.0% and 25.3 ± 12.3% respectively. Resin(-) meals showed a higher percentage of free technetium in the liquid component than resin(+) ones. Conclusions: In resin(-) group, the gastric emptying time is faster and the free technetium in the liquid component is higher than resin(+) group, these results suggest that the rapid gastric emptying in resin(-) group is probably due to rapid emptying of unbound technetium along with liquid component of the meal. • G3361 THE EFFECT OF RED PEPPER AND CAPSAICIN ON GASTRIC EMPTYING IN HUMAN VOLUNTEERS. HJ Park, SK Na, SI Lee, JK Kang, IS Park. Dept. of Internal Medicine, Yonsei University Medical College, Seoul, Korea. Red pepper is used most commonly as a food additive in Korea, and capsaicin is the major pungent ingredient of red pepper. There are conflicting data as to whether ingestion of red pepper causes delayed gastric emptying. Aim: The purpose of this study was to assess the effect of intragastric red pepper and capsaicin on the gastric emptying assessed by radioopaque markers(ROMs) and serial changes of plasma acetaminophen (AAP) levels in human volunteers. Methods: Fourteen healthy male volunteers with a mean age of 29 years were included. Subjects were randomized to receive either placebo, 3g, 6g of red pepper, or 17.3mg of capsaicin. In addition, subjects were ingested 1.5g of AAP and ROMs with the test meal. Gastrointestinal(GI) symptoms were evaluated by a standard questionnaire at 1 hour after ingestion of each test meal. A plain abdominal radiograph was taken 2 and 3 hours after ingestion of the test meal. Blood samples were obtained at 30, 45, 60, 75, 90 rain after ingestion of the test meal. Results: Intragastric capsaicin markedly produced GI symptoms comparing with placebo or red pepper. Intragastric red pepper and capsaicin made no significant difference of plasma AAP level statistically, Red pepper had no effect on gastric emptying of ROMs. Capsaicin significantly delayed gastric emptying of ROMs. Conclusions: We found a delayed gastric emptying of indigestible solid meal after intragastric administration of capsaicin but not after red pepper in human volunteers. The usual amount of red pepper consumed by Koreans did not impair the gastric emptying. • G3362 THE GASTRIC MOTOR FUNCTION IN GASTRIC CANCER AND ITS CORREATION OF C-KIT DENSITY IN CIRCULAR MUSCLE LAYER. HJ Park, JH Kim, SI Lee, JK Kang, IS Park. Dept. of Internal Medicine, Yonsei University Medical College, Seoul, Korea. Gastric motor function in patients with gastric cancer may be dependent upon the extent, depth of invasion, and/or location of cancer. The network of interstitial cell of Cajal(ICC) acts as a pacemaker cell to produce the slow wave, and c-kit plays an important role in development and function of the ICC. Aims:We investigated the gastric motor function in patients with gastric cancer, and examined the density of c-kit* cells in circular muscle layers of the stomach to investigate a possible correlation between gastric motor function and the density of c-kit. Methods: The subjects include 34 patients operated for non-obstructive gastric cancer. Nine cases were in the early gastric cancer(EGC)(mean 54.7yrs.) and 25 were in the advanced gastric cancer(AGC)(mean 55.6yrs.). Preoperative electrogastrography and gastric emptying scan were performed in all patients. The frozen samples of circular muscle without cancer infiltration were prepared and immunohistochemistry for c-kit was performed. Results: There was significantly delay in gastric emptying(T1/2) in EGC and AGC group comparing with controls, but no difference between EGC and AGC group. In the AGC group, Tl/2 or slow wave frequency did not differ regardless of the location of the lesions. The density of c-kit in antrum was greater than in body. No correlation was found between the density of c-kit, T1/2 and the slow wave frequency. Conclusions: We observed a delayed gastric emptying in patients with gastric cancer without any abnormalities in myoelectrical activity. No correlation was found between Tl/2, slow wave frequency and c-kit density in the patients with gastric cancer. • G3363 RECTOGASTRIC REFLEX-INDUCED GASTRIC HYPERSENSITIVITY TO MECHANICAL DISTENTION AND MEAL INGESTION: A POSSIBLE MODEL FOR DYSPEPSIA WITH FUNCTIONAL LOWER GUT DISORDERS. S. Park, F. Hooper, J. Palaniappan, C. Owyang, W. Hasler. Department of Internal Medicine, University of Michigan, Ann Arbor, MI. Many irritable bowel syndrome (IBS) patients report bloating and nausea. Rectal distention is reported to delay gastric emptying but recent studies show no effect of rectal distention on fasting gastric tone. IBS is characterized by altered perception of luminal distention. The effects of rectogastric reflex