Stimulation by nizatidine, a histamine H2-receptor antagonist, of duodenal HCO3- secretion in rats: relation to anti-cholinesterase activity

Figure 4 Effects of atropine or bilateral vagotomy on the HCO₃^- stimulatory action of nizatidine, neostigmine and carbachol in the rat duodenum. The HCO₃^- secretion was measured by perfusing a duodenal loop with saline and by adding 10 mM HCl to the reservoir. Neostigmine (0.03 mg/kg), carbachol (0.01 mg/kg) or famotidine (10 mg/kg) was administered i.v. as a single injection after the basal secretion had well stabilized, and the HCO₃^- secretion was measured for 2 h. Atropine (1 mg/kg) was given s.c. 1 h before admin istration of the above agents. Bilateral vagotomy was performed acutely at the cervical portion 2 h before the administration of the agents. Data are presented as the means ± SE from 6 rats. Significant difference at P < 0.05; ^afrom corresponding groups without atropine; ^bfrom corresponding values observed for 1 h before the treatment (time: -60-0 min)