Abstract
Microinjections of noradrenaline (NA, 0.3, 3.0 and 30.0 μg) into the central amygdalar nucleus (CEA) produced dose-related attenuations of cold restraint (3 h at 4°C) induced gastric ulcer formation in rats. On the other hand, stress ulcer aggravating effects were seen with β-adrenoceptor antagonist, propranolol (10 μg) but not with the α-adrenoceptor antagonist, prazosin (1 and 10 μg). Moderate enhancements of gastric stress lesions were also seen with the NA release inhibitor clonidine (1 μg) and the neurotoxin DSP-4 (25 μg). Further, pretreatment of rats with intra-amygdalar (i.am.) propranolol but not prazosin, antagonized and reversed the gastric cytoprotective effects of NA. The results indicate that β-adrenoceptor-mediated NAergic mechanisms at the level of the CEA are important for the maintenance of gastric mucosal integrity during immobilization stress.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have