Transglutaminase in response to hypertonic NaCl-induced gastric mucosal injury in rats.
BACKGROUND
Polyamines serve as substitutes for transglutaminase-catalyzed protein cross-linking and are essential to the healing of gastric mucosal lesions. This study determines whether transglutaminase and protein cross-linking have a role in the healing of hypertonic NaCl-induced gastric lesions.


METHODS
Rats were fasted 22 hours before given 1 mL 3.4 Mol/L NaCl intragastrically. Gastric mucosa was examined histologically and grossly, and transglutaminase activity was measured as the Ca(2+)-dependent covalent incorporation of [3H]putrescine into acid-precipitable protein.


RESULTS
Transglutaminase activity increased significantly from 2 to 8 hours, peaking between 4 and 6 hours after NaCl administration. Lesions were significantly produced after 2 hours, and damage paralleled transglutaminase activity. Dansylcadaverine (200 mg/kg orally), a specific inhibitor of protein cross-linking, prevented the increases in transglutaminase activity and significantly delayed healing but had no effect on lesion formation.


CONCLUSIONS
These results indicate that (1) hypertonic NaCl-induced gastric mucosal damage is associated with a significant increase in transglutaminase activity and (2) increased transglutaminase activity is involved in the mechanism of normal mucosal healing.
Wang
J Y
JY
Department of Physiology and Biophysics, University of Tennessee College of Medicine, Memphis.
Viar
M J
MJ
Johnson
L R
LR
D000818:Animals; D002103:Cadaverine / Q000031:analogs & derivatives / Q000494:pharmacology; D005753:Gastric Mucosa / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012462:Saline Solution, Hypertonic / Q000494:pharmacology*; D013997:Time Factors; D011503:Transglutaminases / Q000037:antagonists & inhibitors / Q000378:metabolism*
D012462:Saline Solution, Hypertonic; D011503:Transglutaminases; C008542:monodansylcadaverine; D002103:Cadaverine