Electron Microscopic Study on the epithelial Injury following Preservation and Reperfusion of the Small Intestine

1994 Fiscal Year Final Research Report Summary

• Project/Area Number: 05671497
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: 小児外科
• Research Institution: KYUSHU UNIVERSITY
• Principal Investigator: ARIMA Tohru Kyushu University, Faculty of Medicine, Associate Professor, 医学部, 助教授 (90159509)
• Co-Investigator(Kenkyū-buntansha): TAGUCHI Tomoaki Kyushu University, Faculty of Medicine, Assistant Professor, 医学部, 助手 (20197247) ; SUITA Sachiyo Kyushu University, Faculty of Medicine, Professor, 医学部, 教授 (30038856)
• Project Period (FY): 1993 – 1994
• Keywords: small bowel transplantation / intestinal crypt cells / organ preservation / reperfusion / tissue injury / electron microscopy

Research Abstract

Whether the small bowel tissue recovers from the preservation and reperfusion injuries or not depends on the viability of crypt cells. The purpose of this study is to investigate the effect of ultrastructural changes of crypt cells on the recovery of the epithelium.
After jejunal grafts of Lewis rats were preserved in 4ﾟC UW solution for 24 or 48 hours, the syngeneic transplantation was performed in the form of the Thiry-Vella loop. The specimens were taken at the time of graft-harvesting (control), endpoint of cold-storage and after 30 minutes from the beginning of reperfusion.
In the 24-hour-stored group, the grafts survived for more than 10 days in all animals, while no graft survived in the 48-hours-stored group. In the former the villi recovered completely on the light microscopic observation. At the end of cold preservation for both 24 and 48 hours, the epithelial cell degeneration was remarkable in the upper part of the crypts. Although the epithelial linings of both groups were m aintained in the lower part of the crypts, the nuclear heterochromatin increased and mitochondrial granules became conspicuous in the 48-hour-stored group. When the grafts were reperfused for 30 minutes, immature epithelial cells with a few organelles and a large nuclear-cytoplasm ratio aggregated in the basal area of the crypts in the 24-hours-stored group. On the other hand, the destruction of the epithelial linings and the degeneration of the individual cells were severe even in the base of the crypts in the 48-hours-stored group.
The aggregation of the immature cells in the 24-hours-stored group may reflect the good keeping of proliferative activity of epithelial cells. In the 48-hours-stored group, the increase of the nuclear heterochromatin can be interpreted to show inactivity of the chromatin, and the prominence of the mitochondrial granules may suggest the ischemic process in the cells. It is concluded that these ultrastructural findings must be manifestations of the viability of crypt cells and would correlate well to the success or failure of the epithelial restoration.