Adenosine receptor activation in brain reduces stress-induced ulcer formation

Rats restrained in a cold environment for 3 h developed a high incidence of gastric ulcers. Administration of adenosine receptor agonists prior to a restraint period significantly reduced ulcer formation and severity, and lowered plasma corticosterone levels. This protective effect was blocked by 8-phenyltheophylline, a methylxanthine type adenosine receptor antagonist able to permeate the blood-brain barrier. This finding together with the absolute and relative order of potencies with which adenosine receptor agonists produced their effects suggests that CNS adenosine A₁ receptors are involved in blocking and methylxanthines in exacerbating stress-induced gastric pathology.