The role of D1/DA1 dopamine receptors on histamine-and carbachol-induced gastric acid secretion in male rat



Dopamine has an effective role on gastric acid secretion (GAS). The role of peripheral and central dopamine D1/DA1 receptors on stimulated GAS are unknown. The objective of the present study was to use SKF38393 and SCH23390 on stimulated GAS. For all gastric sampling, animals (Sprague Dawley rats) were anesthetized and a polyethylene tube was introduced into the stomach through esophagus and a cannula was inserted into the pylorododenal junction and passed up into the stomach. After washing, the stomach was perfused with physiological saline and perfusate was titrated with NaOH. Intravenous (jugular vein) infusion of histamine- and carbachol-induced marked increased in GAS with a peak response that started from 20 and 30 min respectively up to the experiments. Administration of SKF (1mg/kg) produced a decrease (50 %) in histamine -stimulated GAS. This effect completely removed by SCH23390 (0.1 and 0.01 mg/kg). The acid suppressant effect of SKF was not observed on carbachol-induced GAS. In conclusion, there is probably a regulatory mechanism of GAS by D1 receptors interaction with H2 but not M3 receptors.