Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Protein kinase C(PKC) is a Ca2+- and phospholipid-dependent protein kinase which can be activated by diacylglycerol, a product of polyphosphoinositide hydrolysis. In this report, we show that the polyphosphoinositides L-alpha-phosphatidylinositol 4-monophosphate (PI 4P) and L-alpha-phosphatidylinositol 4,5-diphosphate (PI 4.5DP) can serve as phospholipid cofactors of isolated rat brain PKC. The order of potency of the phosphoinositides in the activation of PKC, PI greater than PI 4P greater than PI 4,5DP, shows a negative correlation with the degree of acidity of the phospholipid head group, whether 1 mM Ca2+ or 200 nM TPA is present in the reaction assay mixture. Although the polyphosphoinositides are by themselves weaker activators of PKC than PI, small amounts of PI 4,5DP cause a two-fold enhancement of PKC in the presence of Ca2+ and PI. While the endogenous phospholipid cofactors of PKC remain to be identified, these results suggest that the small amounts of polyphosphoinositides which are present in cell membranes may play a direct role in the activation of PKC in vivo, by serving as phospholipid cofactors of the enzyme.
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PMID:The activation of protein kinase C by the polyphosphoinositides phosphatidylinositol 4,5-diphosphate and phosphatidylinositol 4-monophosphate. 303 87

Disodium edetate (ethylenediaminetetraacetic acid, disodium salt; disodic EDTA), 3 g, was given, via an intravenous normal saline drip of 30 min, to 25 patients in order to assess a benefit for anaesthesia practice. A significant reduction of both volume and acidity of the gastric secretion was found in all the 10 patients with peptic ulcer having received the drug. The peak of the change was 1 h after administration. In other 10 non-ulcer patients undergoing orthopaedic surgeries under epidural anaesthesia with lidocaine 2%, 5 mg kg-1, pH of the gastric juice unanimously rose, from 2.24 +/- 0.28 to 4.10 +/- 0.21 1 h after EDTA with a P derived from paired difference analysis of less than 0.001. A similar group of patients receiving only normal saline showed no important changes in pH (from 2.37 +/- 0.24 to 2.34 +/- 0.19). The pH of the fundic surface, measured directly under fiberscopic control in further 5 patients suffering from peptic ulcer, was found also to rise from 1.84 +/- 0.21 to 4.62 +/- 0.34 1 h after EDTA, P less than 0.001. Total and ionized calcium changed unsignificantly. Disodic EDTA in the dose and manner used in this study showed no clinical side-effects. The constant and obvious effect of inhibition of the gastric secretion as well as the dynamics of such an action recommend disodic EDTA to be tried in reducing the aspiration pneumonia morbidity.
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PMID:Inhibitory effect of disodium edetate on gastric secretion. 308 72

The highlights of the literature and our work on tetany and hyperventilation are reviewed. Our studies concern the following: (1) the changes of [Ca2+] in circulating plasma caused by respiratory and "metabolic" acidosis and alkalosis; (2) critical plasma [Ca2+] levels associated with signs of tetany and neuromuscular blockade; (3) changes in cerebral [Ca2+]o caused by hypo- and hyper-calcaemia, and the changes in cerebral [Ca2+]o and pHo caused by acute systemic acidosis and alkalosis; and (4) effects of changing [Ca2+]o and pHo levels on synaptic transmission in hippocampal formation. Our main conclusions are (1) changes of plasma [Ca2+] caused by "metabolic" pH changes are greater than those associated with varying CO2 concentration; (2) acute systemic [Ca2+] changes are associated with small cerebral [Ca2+]o changes; (3) the decreases in systemic and cerebral [Ca2+]o caused by hyperventilation are too small to account for the signs and symptoms of hypocapnic tetany; (4) moderate decrease of [Ca2+]o depresses and its increase enhances synaptic transmission in hippocampal formation; and (5) H+ ions in extracellular fluid have a weak depressant effect on neuronal excitability. CO2 is a strong depressant, which is only partly explained by the acidity of its solution. CO2 concentration is a significant factor in controlling cerebral function.
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PMID:Pathophysiology of pH and Ca2+ in bloodstream and brain. 311 5

1. Single-barrelled pH-sensitive microelectrodes filled with liquid ion exchanger were used to study the layer of microclimate pH in the vicinity of the surface of rat jejunum in vitro. 2. During perfusion with a Na+-containing solution of pH 7.30, a layer having a pH gradient ranging from 7.30 (pH of the luminal bulk phase) to 6.05 +/- 0.03 (pH of the deepest region) was detected in eighteen different animals. The thickness of the layer was estimated to be 600-700 microns. No regional difference was seen along the height of the villus. 3. The addition of D-glucose to the perfusion solution significantly augmented the acidity of the deepest region without changing the thickness of the layer. On the other hand, the elimination of Na+ from the perfusion solution caused a significant reduction of the pH gradient. The lowest pH changed from a control value of 6.18 +/- 0.15 (n = 13 measurements from three animals) to 6.46 +/- 0.06 (n = 13). The gradient was sensitive to amiloride in the presence of Na+, K+, Ca2+ and Cl- had no significant effect on the microclimate pH. 4. Depletion of the surface mucus by treatment with dithiothreitol significantly raised the pH of the deepest region. 5. Glycylglycine and L-carnosine were found to reduce the microclimate pH gradient significantly, while glycine did not. 6. These results indicate that H+ secretion by the Na+-H+ antiport and the formation of mucus layer are important factors for maintaining the microclimate pH layer, and that H+-coupled co-transport, such as H+-dipeptide co-transport, causes a significant diminution of the microclimate pH gradient.
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PMID:Factors affecting the microclimate pH in rat jejunum. 344 78

Dairy products, including milk, cheese, and casein, can reduce the caries-causing potential of cariogenic substrates as measured in various animal, plaque acidity, and in vitro systems. Although the mechanisms responsible for protection are not completely identified, substances containing Ca and P may contribute to the protective potential by reducing demineralization and/or promoting remineralization of enamel. Casein may reduce demineralization by forming a protective coat on the enamel surface. By means of a rat model, this study evaluated the ability of three casein-free milk mineral concentrates with various levels of whey protein, calcium, and phosphate to modify the cariogenicity of a powdered diet containing 20% sucrose. Analysis of these data indicates that there were no significant differences among groups for weight gain, total food consumption, or feeding frequency, as monitored by a computer-based infrared activity monitor. All three mineral concentrates significantly reduced buccal caries, and two of the three reduced sulcal caries by from 10 to 30%. The analysis further shows that casein-free milk mineral fractions can modify the cariogenicity of sucrose-containing foods in a rat model.
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PMID:Modification of food cariogenicity in rats by mineral-rich concentrates from milk. 349 61

The data obtained suggest that the sodium ions (0.5-2.0 g) reduce the gastric juice secretion and its acidity whereas magnesium and calcium ions increase the latter. Potassium ions exert practically no effect on the acidity. The suppressing effect of the sodium ions seems to be connected with an increase excretion of sodium chloride with urine as well as with increased diuresis in general. Saluretics suppress the secretion and acidity of the gastric juice on account of increased diuresis and subsequent excretion of large amount of chlorides as well as by means of serotonin release from the Ec cells of the gastro-intestinal tract, the action of serotonin being actualized on the level of the gastric glands' cells, parietal those in particular.
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PMID:[Effect of various cations on the secretory and acid-forming function of the stomach]. 370 82

The ionic compensatory response to CO2 breathing for 3 days was studied on intact and cystectomized turtles at 10 and 20 degrees C. Arterial blood gases, pH, ionized calcium, and the plasma concentrations of Na+, K+, Cl-, total Ca2+, and total Mg2+ were measured periodically. At 20 degrees C, ureteral urine was also collected from bladderless turtles and was analyzed for pH, ions, NH3+, total CO2, osmolality, and titratable acid. When CO2 was breathed there was a compensatory change in the strong-ion difference as manifest by an increase in plasma [HCO3-] that was approximately 10 meq/l both in the 10 and 20 degrees C turtles. The only significant associated strong-ion changes observed consistent with the ionic compensatory response were increases in total and ionized Ca2+ and total Mg2+. These results were unaffected at either temperature by surgical removal of the urinary bladder. Urine collected from cystectomized turtles showed no compensatory increase in acid excretion during hypercapnia; in fact, changes occurred in the opposite direction. Urinary excretion of HCO3- and urine pH increased significantly, whereas titratable acidity decreased significantly. No significant change occurred in ammonia excretion over the three days of hypercapnia. These data argue against compensatory roles for the kidneys and urinary bladder in this species and point to internal ionic exchanges involving bone and shell.
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PMID:Ionic compensation with no renal response to chronic hypercapnia in chrysemys picta bellii. 378 4

The influence of feedstuffs treated with ionizing radiation on the nutrition of dogs was tested in four groups of animals. Two groups were administered for 90 days a ration, the main part of which (VETACAN meat feed mixture and VETAVIT loose feed mixture) was irradiated with radioisotope Co 60 of the intensity of 25 kGy/kg, in other two groups of dogs the nonirradiated ration was used for the same time period. The control groups of dogs were put together for these two diets. The laboratory examination of irradiated feedstuffs confirmed their complete microbiological and mycological intactness. However, the irradiation brought about a significant 35% degradation of essential amino acids with an increase of ammonia nitrogen, destructive changes in the lipid component of feedstuffs and a partial decomposition of the saccharide part of the VETAVIT feed mixture, expressed by the acidity of water extract. The sensory evaluation of irradiated feedstuffs did not show any perceptible alterations. The haematological examination of the blood of animals, which had been administered irradiated feed rations, demonstrated a significant negative influence on the blood picture. The biochemical examination of the blood serum and plasma revealed that total proteins of experimental dogs dropped and the creatinine level was also significantly decreased. Neither was the level of carbohydrate nutrition nor the energy saturation affected by irradiation. The glucose levels in the blood serum of dogs fluctuated within the range of physiological reference values. The growth of free ammoniacal bases of feedstuffs, evoked by ionizing radiation, conditioned obviously the level of actual pH of blood in dogs as determined in this study. The destruction of lipoid fraction in the feedstuffs induced a decrease in the activity of lipophile retinol and thus the biological value of feeds was impaired. The biochemical examination of ALT, AST and ALP enzyme activity did not show any increased activity of parenchyma, in particular of liver cell. A decisive role of the biological quality of feed ration for utilization of some minerals was demonstrated by a significant decrease of the magnesium level in animals administered irradiated feed rations without any biological supplementation. On the contrary, the potassium, calcium and phosphorus levels did not reflect this dietary difference between the groups.
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PMID:[The effect of feeds treated with ionizing irradiation on biochemical indicators of the nutritional value of energy nutrients]. 393 33

The composition of bulk milk of 18 herds of ewes and 14 herds of goats and the milk of 10 individual animals of each ewes and goats during a 12 weeks lactation period was studied. The average percentage of acidity of bulk ewe's milk (0.22), fat (6.4), lactose (4.3), total nitrogen (0.9) calcium (0.169), ash (0.940) and total solids (18.6) were higher than 0.17, 4.0, 3.9, 0.62, 0.130, 0.81 and 12.8 of bulk goat's milk. Phosphorus (0.074) was almost similar to (0.077), while non-protein nitrogen (0.0022) was about thirteen times lower than 0.028 of goat's milk. Determined parameters increased, whereas lactose and non-protein nitrogen decreased with progression of the lactation period. Individual ewe's milk occasionally contained 1.4% fat and 0.56% total nitrogen closely resembling individual goat's milk.
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PMID:The composition of Karadi ewe's and goat's milk. 399 Jul 86

Nifedipine, a calcium-channel antagonist widely used in cardiovascular disease, has recently been reported to be effective in the treatment of oesophageal motor disorders. The effect of a single therapeutic dose of nifedipine (20 mg p.o.) has been evaluated on basal and submaximal pentagastrin-stimulated gastric secretion and meal-stimulated gastrin release in healthy man. In comparison with placebo, nifedipine significantly decreased both basal and stimulated gastric acidity and juice volume, whereas only a slight but insignificant reduction in meal-stimulated gastrin levels was observed after drug administration. The results are in agreement with previous reports that calcium is involved in stimulus-secretion coupling in the human parietal cell. They do not confirm the effect of calcium on G-cells, although it is likely that doses of nifedipine higher than those commonly used might be effective in the reduction of gastrin secretion.
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PMID:Effect of nifedipine on gastric acid secretion and gastrin release in healthy man. 406 91


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