Capillary filtration in the small intestine after irradiation. An experimental study in the cat.

Capillary filtration in the experimentally irradiated small intestine of the cat was studied by measuring the capillary filtration coefficient (CFC). Segments of the small intestine were exposed to X rays of 15, 20, or 25 Gy and studied during the acute gastrointestinal radiation syndrome (4th day) and later (1 and 4 months). On the 4th day CFC had decreased to less than 60% of the original value. Increasing doses resulted in decreasing CFC. One month after irradiation CFC increased, but not to normal levels. After 4 months no further improvement was observed. With the higher doses a secondary decrease in CFC appeared, which might indicate a late effect of irradiation on capillary function.