Gastric mucosal blood flow and gastric secretion following intravenous administration of 5-fluorouracil in anesthetized rats.

Acute gastric mucosal lesions are often observed after the intravenous administration of high doses of anticancer drugs. To investigate the acute toxic effects of such anticancer therapy on the gastric mucosa, 5-fluorouracil (5-FU) was administered intravenously to anesthetized rats. Gastric mucosal blood flow (GMBF) was measured continuously using laser Doppler velocimetry. Acid secretion was measured using a perfusion method for 1 h after the administration of 5-FU. No significant change was observed with a low dose of 5-FU (50 mg/kg), but a high doses of 5-FU (100 or 200 mg/kg) caused a significant decrease in GMBF in a dose-dependent manner. The selective antagonist of the muscarinic acetylcholine receptor, pirenzepine, prevented the decrease in GMBF with high doses of 5-FU. Acid secretion decreased after the administration of 5-FU, but not significantly. This study indicates that a decrease in GMBF may be an important factor in gastric mucosal injury induced by chemotherapy. Pirenzepine may prevent the gastric mucosal lesions which are induced by the administration of 5-FU.