title: Thiocyanate and nitrite inhibit proton translocation in gastric mucosa.
abstract: Isolated frog gastric mucosa was used to study the separation of formation of protons (or their precursors) from proton translocation by using various inhibitors. Both thiocyanate (SCN-) and nitrite (NO2-) inhibit the acid secretion in spontaneously secreting mucosa. The inhibition is reversed when the inhibitor is removed such that the excess acid secreted above baseline in the 'off'-period compensates for the amount inhibited in the 'on'-period. Both agents also inhibit the effect on acid secretion of pulse stimulation with histamine though to a lesser extent. Upon removal of the inhibitor, the total amount of acid secreted in excess of basal is equal to that observed with histamine alone. Likewise, metiamide, an H2-antagonist, also inhibits acid secretion with or without histamine. However, in contrast to SCN- and NO2-, removal of this inhibitor is without effect on the acid-secretion rate. These results indicate that both SCN- and NO2- inhibit the proton translocation rather than the formation of protons or their precursors as is the case with metiamide.
authors.forename: E B
authors.initials: EB
authors.lastname: Ekblad
authors.forename: V
authors.initials: V
authors.lastname: Licko
mesh_terms: D000818:Animals; D000242:Cyclic AMP / Q000494:pharmacology; D005744:Gastric Acid / Q000378:metabolism*; D005753:Gastric Mucosa / Q000187:drug effects*; D006632:Histamine / Q000494:pharmacology; D007700:Kinetics; D008785:Metiamide / Q000494:pharmacology; D009573:Nitrites / Q000494:pharmacology*; D011892:Rana catesbeiana; D012977:Sodium Nitrite / Q000494:pharmacology*; D013861:Thiocyanates / Q000494:pharmacology*
chemical_list: D009573:Nitrites; D013861:Thiocyanates; D008785:Metiamide; C024553:sodium thiocyanate; D006632:Histamine; D000242:Cyclic AMP; D012977:Sodium Nitrite