Salivary Carbonic Anhydrase Protects Gastroesophageal Mucosa from Acid Injury

Saliva contains several factors that protect thealimentary canal mucosa against acidity. We measured thesecretory carbonic anhydrase (CA VI) levels in thesaliva of patients with gastrointestinal disorders using a time-resolved immunofluorometric assay.The mean enzyme concentrations were found to be lower inpatients with verified esophagitis, gastric ulcer, orduodenal ulcer than in control patients with nonacid peptic diseases. The biochemical datafrom the enzyme activity assays and western blots of thehuman gastric mucosa and gastric juice samples indicatedthat the swallowed CA VI probably retains its activity in the harsh environment of thegastric lumen. In the upper alimentary canal, CA VI mayneutralize the acid by catalyzing the formation ofcarbon dioxide and water. The present findings suggest that drugs supplemented with CA VI may provebeneficial in treating acid-peptic diseases.     

Healing of Severe Esophagitis Improves Esophageal Peristaltic Dysfunction

Reflux esophagitis is frequently associated withperistaltic dysfunction, which increases with theseverity of inflammatory lesions. In order to assessperistaltic dysfunction with more accuracy before and after healing, we used a 24-hr pH andpressure recording method. Nineteen patients (medianage: 65, range: 33-77) with stage II and III(Savary-Miller classification) esophagitis andperistaltic dysfunction were treated with 40 mg omeprazole for three tosix months until complete endoscopic healing wasachieved. Before treatment, median contraction amplitudewas significantly lower than median contraction amplitude of a control group of comparable age[31 (21-53) versus 42 (21-77) mm Hg, P < 0.01], aswell as median percentage of peristaltic contractions[27 (16-63) versus 44 (11-56), P < 0.01]. At the end of treatment, a statisticallysignificant improvement of esophageal motor functionswas observed for both median contraction amplitude [38(26-55), P = 0.001] and median percentage of peristaltic waves [45 (23-68), P = 0.0001]. Theposttreatment values, although still low, were notsignificantly different from control values. Inconclusion, complete healing of grade II and IIIesophagitis improves peristalsis. Inflammatory processes related tosevere esophagitis may be involved in failed peristalsisand low contraction amplitude.