Effects of gut hormones on the large bowel injury

1997 Fiscal Year Final Research Report Summary

• Project/Area Number: 07671371
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Digestive surgery
• Research Institution: Tokyo Medical and Dental university
• Principal Investigator: YOSHINAGA Keigo Tokyo Medical and Dental University, Second Department of Surgery, Assistant Professor, 医学部, 講師 (80240745)
• Co-Investigator(Kenkyū-buntansha): MISHIMA Yoshio Tokyo Medical and Dental University, Eneritus Professor (00010158) ; IDE Akitake Tokyo Medical and Dental University, Second Department of Surgery, Instructor (80280965)
• Project Period (FY): 1995 – 1997
• Keywords: bombesin / colitis / large bowel injury / gut hormone / bromodeosyuridine / colostomy / rectal mucosa

Research Abstract

The first purpose of this study was to evaluate the effect of bombesin (BBS) on acetic acid-induced colitis in rats. Male Fischer 344 rats were used. Two end colostomies were made at the descending colon to separate the large bowel. Colitis was induced in the distal segment of large bowel by administration of 4% acetic acid for 15 sec. Rats were administered subcutaneous injection of saline or BBS every 8 h at doses of 3,10 or 30 mug/kg after the operation until the 4th postoperative day (POD). Rats were sacrificed on the 4th POD and the distal segment of large bowel was excised. A histologic grading scale was used for determination of the extent of inflammatory reaction in the mucosa (Scand J Gastroenterol 1993 ; 28 : 155-162). The factors evaluated were ulceration, mucus cell depletion, crypt abscess, inflammatory cyst, mucosal atrophy, edema, inflammatory cell infiltration and vascular dilatation. Administration of BBS significantly decreased the histologic scoring of acetic acid-induced colitis in a dose-related manner.
The second purpose of this study was to evaluate the effect of BBS on the proliferation of rectal and small intestinal mucosa. For analysis of the labelling index of the gut mucosa, the numbers of bromodeoxyuridine (BrdU)-labelled and unlabeled cells in the zone of proliferating cells were counted. The labelling index was expressed as the number of BrdU-labelled cells/total number of cells within the zone proliferating cells. BBS significantly increased the labelling indices of rectal and jejunal mucosa in a dose-related manner. Furthermore, administration of BBS for 5 days at the dose of 30 mug/kg significantly increased the weight and contents of DNA,RNA and protein in rat jejunum.