Brief Article
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Oct 21, 2012; 18(39): 5576-5580
Published online Oct 21, 2012. doi: 10.3748/wjg.v18.i39.5576
Inhibition of gastric perception of mild distention by omeprazole in volunteers
Akihito Iida, Hiroshi Kaneko, Toshihiro Konagaya, Yasushi Funaki, Kentaro Tokudome, Shinya Izawa, Yasuhiro Tamura, Mari Mizuno, Naotaka Ogasawara, Makoto Sasaki, Kunio Kasugai
Akihito Iida, Yasushi Funaki, Kentaro Tokudome, Shinya Izawa, Yasuhiro Tamura, Mari Mizuno, Naotaka Ogasawara, Makoto Sasaki, Kunio Kasugai, Division of Gastroenterology, Department of Internal Medicine, School of Medicine, Aichi Medical University, Aichi 480-1195, Japan
Hiroshi Kaneko, Department of Internal Medicine, Hoshigaoka Maternity Hospital, Aichi 464-0026, Japan
Toshihiro Konagaya, Marine Clinic, Nagoya, Aichi 460-0002, Japan
Author contributions: Iida A, Kaneko H, Konagaya T, Ogasawara N, Sasaki M, and Kasugai K designed the research; Iida A, Kaneko H, Konagaya T, Funaki Y, Tokudome K, Izawa S, Tamura Y, and Mizuno M performed the research; Iida A and Konagaya T analyzed the data; and Iida A and Kaneko H wrote the manuscript.
Supported by A Grant-in-Aid for Scientific Research from the Aichi Medical University Alumni Association, in part
Correspondence to: Akihito Iida, MD, PhD, Assistant Professor, Lecturer, Division of Gastroenterology, Department of Internal Medicine, School of Medicine, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi 480-1195, Japan. iida@aichi-med-u.ac.jp
Telephone: +81-561-623311 Fax: +81-561-621508
Received: June 9, 2012
Revised: August 13, 2012
Accepted: August 25, 2012
Published online: October 21, 2012
Abstract

AIM: To evaluate the effects of omeprazole on gastric mechanosensitivity in humans.

METHODS: A double lumen polyvinyl tube with a plastic bag was introduced into the stomach of healthy volunteers under fluorography and connected to a barostat device. Subjects were then positioned so they were sitting comfortably, and the minimal distending pressure (MDP) was determined after a 30-min adaptation period. Isobaric distensions were performed in stepwise increments of 2 mmHg (2 min each) starting from the MDP. Subjects were instructed to score feelings at the end of every step using a graphic rating scale: 0, no perception; 1, weak/vague; 2, weak but significant; 3, moderate/vague; 4, moderate but significant; 5, severe discomfort; and 6, unbearable pain. After this first test, subjects received omeprazole (20 mg, after dinner) once daily for 1 wk. A second test was performed on the last day of treatment.

RESULTS: No adverse effects were observed. Mean MDP before and after treatment was 6.3 ± 0.3 mmHg and 6.2 ± 0.5 mmHg, respectively. One subject before and 2 after treatment did not reach a score of 6 at the maximum bag volume of 750 mL. After omeprazole, there was a significant increase in the distension pressure required to reach scores of 1 (P = 0.019) and 2 (P = 0.017) as compared to baseline. There were no changes in pressure required to reach the other scores after treatment. Two subjects before and one after omeprazole rated their abdominal feeling < 1 at MDP, and mean (± SE) abdominal discomfort scores at MDP were 0.13 ± 0.09 and 0.04 ± 0.04, respectively. Mean scores induced by each MDP + 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20 (mmHg) were 1.1 ± 0.3, 2.0 ± 0.4, 2.9 ± 0.5, 3.3 ± 0.4, 4.6 ± 0.3, 5.2 ± 0.3, 5.5 ± 0.2, 5.5 ± 0.3, 5.7 ± 0.3, and 5.4, respectively. After omeprazole, abdominal feeling scores for the same incremental pressures over MDP were 0.3 ± 0.1, 0.8 ± 0.1, 2.0 ± 0.4, 2.8 ± 0.4, 3.8 ± 0.4, 4.6 ± 0.4, 4.9 ± 0.3, 5.4 ± 0.4, 5.2 ± 0.6, and 5.0 ± 1.0, respectively. A significant decrease in feeling score was observed at intrabag pressures of MDP + 2 mmHg (P = 0.028) and + 4 mmHg (P = 0.013), respectively, after omeprazole. No significant score changes were observed at pressures ≥ MDP + 6 mmHg.

CONCLUSION: Although the precise mechanisms are undetermined, the present study demonstrated that omeprazole decreases mechanosensitivity to mild gastric distension.

Keywords: Functional dyspepsia; Acid exposure; Ome-prazole; Barostat test; Mechanosensitivity