Untitled

Abstract

Saliva contains several factors that protect the alimentary canal mucosa against acidity. We measured the secretory carbonic anhydrase (CA VI) levels in the saliva of patients with gastrointestinal disorders using a time-resolved immunofluorometric assay. The mean enzyme concentrations were found to be lower in patients with verified esophagitis, gastric ulcer, or duodenal ulcer than in control patients with nonacid peptic diseases. The biochemical data from the enzyme activity assays and western blots of the human gastric mucosa and gastric juice samples indicated that the swallowed CA VI probably retains its activity in the harsh environment of the gastric lumen. In the upper alimentary canal, CA VI may neutralize the acid by catalyzing the formation of carbon dioxide and water. The present findings suggest that drugs supplemented with CA VI may prove beneficial in treating acid-peptic diseases.

Carbonic Anhydrase as a Model for Biophysical and Physical-Organic Studies of Proteins and Protein−Ligand Binding

“…The affinity for BCA II of the benzenesulfonamide with four Gly residues (71, K d ≈ 210 nM) was ~3-fold lower than those for 69 and 70. The affinities of benzyl-ether-terminated benzenesulfonamides with tails of oligoethylene glycol (77)(78)(79)(80)(81)(82) for BCA II decreased monotonically with increasing tail length, but only by a factor of 2 over the range of one (77) to six (82) residues. These affinities were only 4-5-fold higher than for methyl-ether-terminated benzenesulfonamides with oligoethylene glycol tails (72)(73)(74)(75)(76).…”

The identification of secreted carbonic anhydrase VI as a constitutive glycoprotein of human and rat milk

“…For example, CA VI displaces 125 I-NGF bound to enriched taste bud membrane fractions (24). Although the exact physiological significance of milk CA VI remains undefined here, we suggest that, as an acid-resistant enzyme (11), it may function as a trophic growth factor in the infant alimentary tract, which undergoes pronounced growth and functional maturation during the immediate postnatal period.…”

“…Recent studies have, in turn, provided new information about the function of the secretory CA VI. It has been proposed that this isoenzyme may participate in protecting the teeth from caries (10) and in neutralizing excess acid in the mucous layer covering the esophageal and gastric epithelium (11). Another novel role for CA VI became apparent when Thatcher et al (12) identified gustin, a salivary factor implicated in taste bud growth, as CA VI.…”

“…Thus, during the early postnatal period, CA VI is transferred to the infantile alimentary tract in the milk in concentrations that exceed the levels found in adult human saliva several times over. These high concentrations of CA VI found in colostral and mature milk, its functional and structural stability in an acidic milieu (11), and its growthsupporting role in taste buds (12) suggest that milk CA VI not only is linked to the functions of the upper gastrointestinal tract but also may participate in normal growth and development of the whole alimentary tract.…”

Purification of Carbonic Anhydrase Isozyme VI (CA-VT) from Swine Saliva.

“…CA-VI has been purified from saliva or parotid glands of humans [10], rats [3] and cattle [1,5]. It may participate in the regulation of salivary pH and buffer capacity and protect the upper alimentary canal against excess acidity [13]. Kivela et al reported that salivary CA-VI is not directly involved in the regulation of pH in saliva [8].…”