[Autonomic nervous system and gastric stress in rats]

The role of the autonomic nervous system on gastric stress was studied in different groups of Wistar rats (n = 10). The experimental stress model consisted of immobilization and immersion in 15 degrees C water during 6 hours. The percentage of the gastric mucosa macroscopic lesional area was tabulated, and at the same time cortisol, melatonin, noradrenaline, adrenaline, dopamine and serotonin blood levels were measured. The stress control showed a necrotic area (80%) and in blood there was only and increase in noradrenaline and adrenaline. The following dose dependent drugs were studied: beta adrenergics agonists and antagonists, alpha 1 postsinaptical adrenergic antagonists, anticholinergics and cholinergics, endorphin and GABA receptors. Isoproterenol, prazosim, doxasine, tramadol and vigabatrin yielded a remarkable gastric mucosa protection in stress with an area close to 0% (p < 0.001). In contrast, propanolol, acetylholine, atropine, naloxone and flumazenil showed no difference in control stress (p > 0.5). All the drugs under study yielded similar vasoactive amines than the control stress. It is concluded that the protective gastric mechanism of the autonomic nervous system in stress, could be linked to its receptors with an increase in the splanchnic microcirculation.