Brain ischemia and gastric mucosal damage in spontaneously hypertensive rats
Brain ischemia is often accompanied by acute gastric lesions. To clarify the underlying mechanism, the influence of acute ischemic insult to the brain on gastric hemodynamics and mucosal integrity was examined in spontaneously hypertensive rats. One hour after brain ischemia, gastric mucosal blood flow decreased to 71% of the preischemic levels in the control rats but was preserved significantly better, at 94 and 108%, in the prazosin-treated and guanethidine-treated rats, respectively. Vagotomy almost abolished the decrease in gastric mucosal blood flow during cerebral ischemia. Intragastric 0.6 N hydrochloric acid administered just after reperfusion induced more severe hemorrhagic ulcers in the control than in the prazosin-treated and vagotomized groups. These results suggest that noradrenergic neurons acting through α1-adrenoceptors contributes to the decrease in gastric mucosal blood flow, and the subsequent disturbed integrity of the gastric mucosa, through the vagal adrenergic pathway during brain ischemia in spontaneously hypertensive rats.
Key wordsbrain ischemia gastric mucosal blood flow integrity of the gastric mucosa vagal adrenergic pathway
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- 23.Izumiyama K, Kogure K: Experimental analysis of gastric mucosal blood flow after transient forebrain ischemia. Res Exp Med 190:301–303, 1990Google Scholar
- 24.Boura AL, Green AF: Adrenergic neuron blocking agents. Annu Rev Pharmacol 5:183–212, 1965Google Scholar
- 25.Furst CI: The biochemistry of guanethidine. Adv Drug Res 4:133–161, 1967Google Scholar
- 26.Lundberg J, Ahlman H, Dahlström A, Kewenter J: Catecholamine-containing nerve fibres in the human abdominal vagus. Gastroenterology 60:81–84, 1971Google Scholar
- 28.Guth PH, Leung FW: Physiology of the gastric circulation.In Physiology of the gastrointestinal tract, 2nd ed, LR Johnson, J Christensen, MJ Jachson, ED Jacobson, JH Walsh (eds). New York, Raven Press, 1986, pp 1031–1053Google Scholar