Effects of insulin-like growth factor-I administration on radiation enteritis in rats.
BACKGROUND
Acute radiation-induced damage to the small bowel occurs frequently during abdominal radiotherapy. Since the small intestine is selectively responsive to the growth-promoting effects of insulin-like growth factor-I (IGF-I), we investigated the effects of IGF-I administration on mucosal recovery from radiation enteritis in the rat.


METHODS
Rats received a single 10-Gy dose of total abdominal irradiation followed by implantation of mini-pumps infusing either IGF-I or vehicle for 4 days. After the rats had been killed, gut organs were weighed before light microscopic and biochemical examination.


RESULTS
Irradiated rats receiving IGF-I lost less body weight than vehicle-treated rats, whereas the wet weights of the stomach, small intestine, and colon were increased by 10%, 19%, and 21%, respectively, and crypt depth was increased in the duodenum, jejunum, and ileum.


CONCLUSIONS
IGF-I administration after abdominal irradiation increased small-intestinal mass and improved indicators of mucosal integrity, suggesting acceleration of small-intestinal mucosal recovery from radiation injury.
Howarth
G S
GS
Child Health Research Institute, North Adelaide, South Australia, Australia.
Fraser
R
R
Frisby
C L
CL
Schirmer
M B
MB
Yeoh
E K
EK
D000818:Animals; D001835:Body Weight / Q000187:drug effects / Q000528:radiation effects; D003106:Colon / Q000473:pathology; D004195:Disease Models, Animal; D004386:Duodenum / Q000187:drug effects / Q000528:radiation effects; D004751:Enteritis / Q000188:drug therapy* / Q000209:etiology; D007082:Ileum / Q000187:drug effects / Q000528:radiation effects; D007334:Insulin-Like Growth Factor I / Q000008:administration & dosage* / Q000627:therapeutic use; D007413:Intestinal Mucosa / Q000187:drug effects / Q000528:radiation effects; D007421:Intestine, Small / Q000473:pathology; D007583:Jejunum / Q000187:drug effects / Q000528:radiation effects; D008297:Male; D009929:Organ Size / Q000187:drug effects / Q000528:radiation effects; D011833:Radiation Injuries, Experimental / Q000209:etiology; D011839:Radiation, Ionizing; D051381:Rats; D017207:Rats, Sprague-Dawley; D013270:Stomach / Q000473:pathology
D007334:Insulin-Like Growth Factor I