Age-Related restraint ulcer formation and thermoregulation in rats treated with purinergic drugs

The effects of the potent adenosine A_1-receptor agonist N^6-cyclohexyl adenosine (CHA) and CHA plus diazepam on the grastric ulcer and thermoregulation were investigated in the right side down restraint male rats with three different ages (2, 6, 12-months-old respectively) . Rats which were exposed to restraint plus CHA for 3 hr developed more gastric lesions as compared tp cpntrol rats which had vehicle and were similary restrained. Six-months-old rats developed the most marked gastric lesions, 2-months-old rats the least and 12-months-old medium. It was suggested that the activity of the adenosine A_1-receptor may be most marked in the mature adult rats. Core body temperature measures revealed that 6-month-old rats with CHA were more successful in maintainig body temperature as compared tp 2- and 12-month-old rats with CHA. Therefore it was suggested that the hypothrmia perse was not necessarily parallel to the degee of resraint ulcer. Twelve-month-old rats which were exposed to the 3 hr restraint and diazepam plus CHA significantly increased the gastric lesions as sompared to the same age group which had only CHA and were similarly restrained. It was suggested that this action of diazepam was due to the inhibition of adenosine uptake and in the old, there might be a decrease in adenosine uptake.