Volume 114, Issue 3, Pages 527-535 (March 1998) Inhibition of rabbit duodenal bicarbonate secretion by ulcerogenic agents: Histamine- dependent and -independent effects  Christopher P. Myers, Daniel Hogan, Biguang Yao, Michael Koss, Jon I. Isenberg, Kim E. Barrett  Gastroenterology  Volume 114, Issue 3, Pages 527-535 (March 1998) DOI: 10.1016/S0016-5085(98)70536-0 Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 1 Effect of 20 μmol/L PGE2 on (A) bicarbonate secretion and (B) Isc across rabbit duodenal tissues in the presence (closed symbols) or absence (open symbols) of aspirin (ASA, 1 μmol/L). PGE2 and aspirin were added serosally at the times indicated by the arrows. Values are means ± SEM for four experiments. **P < 0.01, ***P < 0.001, significant differences from data obtained in the absence of aspirin (Student's t test). Gastroenterology 1998 114, 527-535DOI: (10.1016/S0016-5085(98)70536-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 2 Effect of 20 μmol/L PGE2 on (A) bicarbonate secretion and (B) Isc across rabbit duodenal tissues in the presence (closed symbols) or absence (open symbols) of 15% ethanol (EtOH). PGE2 and ethanol were added serosally at the times indicated by the arrows. Values are means ± SEM for four experiments. **P < 0.01, ***P < 0.001, significant differences from data obtained in the absence of ethanol (Student's t test). Gastroenterology 1998 114, 527-535DOI: (10.1016/S0016-5085(98)70536-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 3 Effect of 50 μmol/L ranitidine (RAN) on the inhibitory effect of (A) aspirin (1 μmol/L) or (B) ethanol (15%) on basal bicarbonate secretion as well as that stimulated by 20 μmol/L PGE2. All agents were added to the serosal side of the tissue at the times indicated by the arrows. Values obtained in the presence (open symbols) or absence (closed symbols) of ranitidine are shown. Data are means ± SEM for four experiments.*P < 0.05, **P < 0.01, significant differences in the presence of ranitidine from data obtained in its absence (Student's t test). Gastroenterology 1998 114, 527-535DOI: (10.1016/S0016-5085(98)70536-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 4 Effect of 100 nmol/L TTX on the inhibitory effect of (A) aspirin (1 μmol/L) or (B) ethanol (15%) on basal bicarbonate secretion as well as that stimulated by 20 μmol/L PGE2. All agents were added to the serosal side of the tissue at the times indicated by the arrows. Values obtained in the presence (open symbols) or absence (closed symbols) of TTX are shown. Data are means ± SEM for four experiments. *P < 0.05, **P < 0.01, ***P < 0.001, significant differences in the presence of TTX from data obtained in its absence (Student's t test). Gastroenterology 1998 114, 527-535DOI: (10.1016/S0016-5085(98)70536-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 5 Effect of aspirin on histamine release from rabbit duodenum. Values are means ± SEM for 8–10 experiments. Histamine release induced in the presence of vehicle (0.1% dimethyl sulfoxide) alone is designated as the control. *P < 0.05, significant difference in histamine release values from control data (ANOVA with Bonferroni post hoc test). Gastroenterology 1998 114, 527-535DOI: (10.1016/S0016-5085(98)70536-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 6 Effect of ethanol on histamine release from rabbit duodenum. Values are means ± SEM for four experiments. *P < 0.05; **P < 0.01, significant differences in histamine release values from those obtained in the absence of ethanol (ANOVA with Tukey–Kramer post hoc test). Gastroenterology 1998 114, 527-535DOI: (10.1016/S0016-5085(98)70536-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 7 Effect of aspirin (100 nmol/L; ▾), ethanol (7.5%; ▴), or the combination of aspirin plus ethanol (♦) on basal bicarbonate secretion and that stimulated by PGE2 (20 μmol/L). All agents were added serosally at the times indicated by the arrows. The data represent means ± SEM for four (aspirin or ethanol alone) or seven (combination of aspirin plus ethanol) experiments. *P < 0.05; **P < 0.01; ***P < 0.001, significant differences from values obtained in the presence of both aspirin and ethanol (ANOVA with Tukey–Kramer post hoc test). Gastroenterology 1998 114, 527-535DOI: (10.1016/S0016-5085(98)70536-0) Copyright © 1998 American Gastroenterological Association Terms and Conditions