Gastric juices

Problems of pH in gastric juice may be overcome by bringing the samples to pH 6.2—7.2 with sodium hydroxide prior to ionised calcium analysis. In this way, calcium ion-selective electrode studies [248] have shown that the appearance of calcium in gastric juice involves both secretory and non-parietal components. A four-component model was developed to account for the observed calcium 

The electrode data appeared compatible with the assumed composition of non-parietal calcium, and in pure secretory fluid the calcium is mostly ionised suggesting that if calcium enters the juice physically bound to pepsin, P, it is displaced from the protein molecule by hydrogen in the very acid juice [248]  

Cerebrospinal fluid and saliva present no problems in terms of pH, and ion determinations on saliva could benefit from a wider application of combination (sensor and reference) electrodes. Such a device can be developed for calcium now that sensor membranes with the sensing liquid ion-exchanger trapped in a PVC matrix are well established. 

To date, outside of dental matters considered later, the main ion-selective electrode interest on saliva has been the use of sodium glass electrodes for monitoring sodium levels in connection with cystic fibrosis screening, the high sodium content of parotid saliva being one characteristic of the disease [249, 250]. 

Ion-selective electrode sweat tests for cystic fibrosis 

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Gunzherg s reagent (detection of HCl in gastric juice) dissolve 4 g of phloroglucinol and 2 g of vanillin in 100 mL of absolute alcohol use only a freshly prepared solution. 

HCl shown to be present in gastric juices of animals by P. Sommerfeld... 

EP 136 463 (Bioresearch appl. 1.8.1984 I-prior. 24.8.1983). gastric juice resistant form ... 

FIGURE 22 Release of radioactivity from polymer discs prepared from 3,9-bis(ethylidene-2,4,8,10-tetraoxaspiro[5,5]undecane) and 35 65 mole ratio of trans-cyclohexane dimethanol and [l C]l,6-hexanediol in phosphate buffer and canine gastric juice at 37°C. Polymer conteuned 2.0% phthalic anhydride. (From Ref. 31.)... 

Fix, J. A., and Leppert, P. S., Erodible poly(ortho ester) drug delivery systems In vitro erosion in canine and USP-stimulated gastric juice, J. Control. Rel., 4, 87-95, 1986. 

There are two main classes of proteolytic digestive enzymes (proteases), with different specificities for the amino acids forming the peptide bond to be hydrolyzed. Endopeptidases hydrolyze peptide bonds between specific amino acids throughout the molecule. They are the first enzymes to act, yielding a larger number of smaller fragments, eg, pepsin in the gastric juice and trypsin, chymotrypsin, and elastase secreted into the small intestine by the pancreas. Exopeptidases catalyze the hydrolysis of peptide bonds, one at a time, fi"om the ends of polypeptides. Carboxypeptidases, secreted in the pancreatic juice, release amino acids from rhe free carboxyl terminal, and aminopeptidases, secreted by the intestinal mucosal cells, release amino acids from the amino terminal. Dipeptides, which are not substrates for exopeptidases, are hydrolyzed in the brush border of intestinal mucosal cells by dipeptidases. 

A biochemical catalyst is called an enzyme. Enzymes are specialized proteins that catalyze specific biochemical reactions. Some enzymes are found in extracellular fluids such as saliva and gastric juices, but most are found inside cells. Each type of cell has a different array of enzymes that act together to determine what role the cell plays in the overall biochemistry of the organism. Enzymes are complicated molecules. Biochemists have determined the molecular structures of some enzymes, but the structures of many enzymes are not yet known. 

KROGDAHL A, HOLM H (1981) Soybean proteinase inhibitors and human proteolytic enzymes selective inactivation of inhibitors by treatment with human gastric juice. /M/fr. Ill 2045-51. 

Figure 2. Correlation between pH and gastric juice of patients in Narino,...

After our formulation of the hypothesis in 1975, many pieces of evidence have come to support the basic theme. A positive association of dysplasia, representing advanced stages of the process, with nitrite levels in the gastric juice has been reported in England and Colombia (, . Higher than expected... 

Sobala, G.M., Crabtree, J., Dixon, M.F., Schorah, C.J., Taylor, J.D., Rathbone, B.J., Heatley, R.V. and Axon, A.T.R. (1991a). Acute Helicobacter pylori infection clinical features, local and systemic immune response, gastric mucosal histology and gastric juice ascorbic acid concentrations. Gut 32, 1415-1418. 

A Gastric juice, vinegar, human blood, baking soda... 

B Baking soda, human blood, vinegar, gastric juice... 

During normal processes, approximately 9 liters of fluid traverse the gastrointestinal tract daily. Of this amount, 2 liters represent gastric juice, 1 liter is saliva, 1 liter is bile, 2 liters are pancreatic juice, 1 liter is intestinal secretions, and 2 liters are ingested. Of these 9 L of fluid presented to the intestine, only about 150 to 200 mL remain in the stool after reabsorptive processes occur. 

Fig. 13 Rate of dissolution of phenacetin from powder, granules, and tablets in diluted gastric juice (Surface Tension, 42.7 dyn/cm pH 1.85). 0> Phenacetin Powder , Phenacetin Granules , Phenacetin Tablets. (From Ref. 17.). 

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