Abstract
Mucosa of small intestine is radiation-sensitive and damaged severely by abdominal expose of high dose radiation caused by nuclear accident or tumor therapy. To find the therapeutic methodology for the intestinal radiation damage, we constructed an experimental mouse model to estimate the effects of drugs. Damage of the mucosa of small intestine was induced by abdominal exposure of LD50 dose of 15.7 Gy of x-ray to anesthetized C3H/He mice. Regeneration of damaged mucosa was initiated 4 days after radiation and the levels reflected BrdU-incorporating microcolony rate and c-myb mRNA level in mucosa. Various drugs were injected with nutrient for 1 to 10 days after radiation and the effects of the drugs were compared. Drugs such as histamine, antithyroid drug and antidiuretic drug accelerated the regeneration rate and increased the survival rate. On the contrary, thyroid hormone and antihistamine drugs decreased the survival. Similarly to our previous report of the effects of anabolic steroids (Radiat. Res. 175, 367), conventional pharmaceutical drugs can be used to ameliorate intestinal mucosal damage by radiation.