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)

The gastrointestinal (GI) physiology of beagle dogs was regulated with a combined-treatment of intramuscular pentagastrin (10 micrograms/kg x 2) and intravenous atropine sulfate (0.02 mg/kg x 1). Here, the gastric acidity, the gastric emptying time and the small intestinal transit time in the regulated-dogs were respectively around pH 2, 0.7h and 4h, approximating those in healthy humans. The superiority of the regulated-dogs over the intact dogs was confirmed in comparative bioavailability studies by using two classes of commercial preparations. Both the conventional tablet and the sustained-release capsule of diclofenac sodium exhibited simple and similar average plasma concentration-time curves of free diclofenac in the intact dogs, while the latter preparation is reported to reveal a bimodal plasma curve of the drug in healthy humans. The regulated-dogs, however, permitted a bimodal average plasma pattern of the drug for the capsules due to an approximation of the GI physiology between humans and these classes of the dogs. The combined-treatment of beagle dogs with pentagastrin and atropine sulfate seems to supply a useful animal model in predicting the absorption characteristics of the sustained-release preparations and poor water-soluble drugs.
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PMID:Bioavailability study of commercial sustained-release preparations of diclofenac sodium in gastrointestinal physiology regulated-dogs. 129 33

Studies were undertaken in cultured opossum kidney (OK) cells to determine whether the rate of H+ secretion by apical membrane Na+/H+ exchange is modulated by changes in extracellular pH or perfusion rate. H+ secretion was assessed in single cells by measuring the rate of Na(+)-dependent intracellular pH recovery after NH4Cl loading, using the pH-sensitive fluorescent dye, 2'7'-bis(carboxyethyl)-5,6-carboxyfluorescein, in monolayers mounted to allow independent perfusion of the apical and basolateral surfaces. At constant intracellular pH, Na(+)-dependent H+ secretion was found to be inversely related to extracellular H+ activity, and directly related to the perfusate flow rate. Inhibition of H+ secretion by perfusate acidity occurred immediately and was greater when perfusate Na+ was reduced, consistent with H+ competition with Na+ for binding to the transporter. By contrast, the effect of the perfusion rate was a delayed response, requiring 20 min of exposure, and was independent of perfusate Na+ concentration. The results indicate that both extracellular pH and the perfusion rate modulate H+ secretion by OK cells, and that the two effects are independent.
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PMID:Influence of extracellular pH and perfusion rate on Na+/H+ exchange in cultured opossum kidney cells. 132 Feb 50

The effect of urine pH on plasma disposition of ampicillin sodium was evaluated. A single dose of 10 mg/kg of body weight was administered IV to Thoroughbreds with alkaline (pH greater than 8.0) or acidic (pH less than 4.5) urine. Urine alkalinity was achieved and maintained by oral administration of up to 400 mg of sodium bicarbonate/kg/d, and acidity was achieved and maintained by oral administration of up to 400 mg of ammonium chloride/kg/d. Ampicillin sodium was measured in the plasma of horses by use of an agar diffusion microbiological assay with Bacillus subtilis as the test organism. The plasma disposition kinetics of ampicillin sodium best fitted a 2-exponential decay pattern, and statistically significant differences were not evident in elimination half-life, area under the plasma concentration time curve, volume of distribution, or body clearance rate between horses with alkaline or acidic urine. Results indicate that changes in urine pH over a range encountered in clinically normal horses are unlikely to affect plasma pharmacokinetic variables of ampicillin sodium after IV administration of the drug.
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PMID:Effect of changes in urine pH on plasma pharmacokinetic variables of ampicillin sodium in horses. 132 42

Chicken pathogenic Escherichia coli strains were found to autoagglutinate in a static culture of trypticase soy broth (TSB). One strain, designated PDI-386, was further studied for its autoagglutinating property. Acidity in the cultured medium caused by glucose degradation induced the autoagglutination. The bacterial cells grown in a glucose-free L-broth could be aggregated by adding acid, which suggests a potentiality of autoagglutination of the strain grown in the L-broth. The autoagglutinating parent (Agg) formed small colonies with irregular edges like rough colonies on the TS agar, whereas its non-autoagglutinating variant (Nag) formed larger smooth colonies with a perfectly round edge. The Nag colony was easily generated from the Agg colony on the TS agar. The autoagglutinating property was very unstable when the bacteria was passed in the TSB, but rather stable in the L-broth. Under electron microscope, the Agg were found to possess pili of more than 20 microns in length. However, the phenotypic expression of autoagglutination did not correlate with that of mannose-sensitive hemagglutination against guinea pig erythrocytes. Incubation of the Nag in the L-broth at room temperature for more than 10 days provoked the reversion of the autoagglutination. There was no difference between the Agg and the Nag in terms of surface hydrophobicity, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns of membrane proteins and LPS, and plasmid profiles. The virulence of the Agg was higher than that of the Nag. The autoagglutination property is, however, so unstable that the pathogenicity of E. coli isolates from chickens should be carefully evaluated.
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PMID:Acid-induced autoagglutination found in chicken pathogenic Escherichia coli strain. 135 89

No evidence of renal involvement was found in 104 patients with rheumatoid arthritis in routine laboratory tests, including serum creatinine, urea, uric acid, sodium, potassium, calcium, phosphorus, and urinalysis. In view of recent publications (1-9) which report renal involvement in rheumatoid arthritis, we studied 16 patients of our group (nonrandomized, 3 men and 16 women, average age 55.4 years, average duration of disease 11.9 years). We examined creatinine clearance, urinary excretion of alpha-2 microalbumin, beta-2 microglobulin, cystine, and urine concentration and acidity after a 10-hour fast. 10 patients had disturbances in 1 or more of the functions examined, in 9 of whom tubular functions were involved. In 6 there was no evidence of renal involvement. There was no correlation between renal involvement and past or present therapy, but there were direct correlations between renal involvement, duration of disease and age. Thus we found evidence for subclinical renal damage not revealed by routine laboratory tests in patients with rheumatoid arthritis. This damage should be taken into consideration when operation, examination with contrast material, or treatment with other nephrotoxic agents are being considered in these patients.
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PMID:[Subclinical renal involvement in rheumatoid arthritis]. 145

Ruminant animals have evolved a large and complex set of stomachs which allow fermentation of fibrous food by symbiotic micro-organisms. These stomachs are well innervated and generate signals which are thought to be important in the control of voluntary food intake. Tension receptors in the muscular wall of the rumen and reticulum are slowly adapting and provide a measure of distension while epithelial receptors are rapidly adapting and provide information on the fibrousness of the digesta; they are involved in the control of stomach motility and voluntary food intake in order to prevent excessive distension. The epithelial receptors are also sensitive to the chemical nature of the digesta, particularly acidity. There are mechano- and chemoreceptors in the abomasum (true stomach) and duodenum and chemoreceptors in the liver, all of which have been implicated in the control of intake. It is relatively easy to prepare and maintain ruminants with a rumen fistula and many studies have shown the effects of such manipulations as distension of balloons in the rumen on voluntary intake. With fibrous, slowly digested feeds intake is primarily limited by rumen distension. With more rapidly digested feeds, however, the products of digestion play an important role in controlling intake. Short-chain fatty acids are the main products of fermentation and infusion of their salts into the rumen depresses food intake to a much greater extent than infusion into the general circulation. Acetate or propionate given into the rumen are more effective, mole for mole, than butyrate but must be given at rates exceeding the natural rate of production in order to have a significant effect. It has been suggested that much of the effect of sodium acetate is via the increase in the osmolality of rumen fluid but there is considerable uncertainty as to the physiological significance of osmotic effects, especially when animals have free access to water and can prevent excessive increases in tonicity by increasing their water intake. Other constituents of rumen fluid have been implicated in the control of food intake, particularly lactic acid and nitrogenous compounds, especially as these can be found in fermented feeds such as silage. The omasum controls the flow of digesta to the abomasum; it is therefore well placed to control rumen fill and thus intake but there has been little study in this area and this is also true for the abomasum.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Abdominal chemo- and mechanosensitivity in ruminants and its role in the control of food intake. 154 91

To test the hypothesis that O2 chemoreception in the carotid body (CB) is mediated by cellular acidosis, we simultaneously measured responses of the chemosensory and intracellular pH (pHi) to agents that are known to change pHi and studied the effects of hypoxia and ischemia on these variables in the cat CB. The CB was perfused and superfused in vitro with a modified Tyrode's solution at 36.0 +/- 0.5 degrees C with or without CO2-HCO3- (pH 7.40) and equilibrated at a given PO2. Chemosensory discharges were recorded from the whole carotid sinus nerve. To measure pHi changes, the CB was loaded with the pH-sensitive indicator 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein, and the fluorescence (excitation 420-490 nm, emission greater than 515 nm) was detected by an intensified charged coupled device camera with an epifluorescence macroscope. Boluses of Tyrode's solution (0.5 ml, free of CO2-HCO3-) containing sodium acetate or NH4Cl prolonged perfusion of acid Tyrode's solution (pH 7.20-6.50), and boluses of Tyrode's solution with CO2-HCO3- were used. A decrease of fluorescence indicated pHi turning acid, and an increase of fluorescence indicated a change in alkaline pHi. Chemosensory activity varied inversely with the fluorescence change after application of these agents. Interruption of perfusate flow or application of hypoxic perfusate resulted in large increases in chemosensory discharge without any change in the fluorescence. The results indicated that chemosensory responses to brief ischemia and hypoxia were not mediated by a fall of pHi of CB cells, whereas those to CO2 and extracellular acidity were associated with decreases in pHi.
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PMID:Intracellular pH and oxygen chemoreception in the cat carotid body in vitro. 162 81

The effect of a decrease (and/or fermentation) in the lactose content during milk storage under different conditions was investigated on the accuracy of the results obtained on a Milko-Scan apparatus to contribute to the present knowledge of this problem. The results were in agreement with some results cited in the literature. These wavelengths are used for infrared spectrophotometry on the above apparatus: for fat 3.48 microns, for proteins 6.46 microns and for lactose 9.60 microns. Bulk milk samples used for the tests were untreated or treated with potassium dichromate, bronopol, sodium azide and Milkofix at the temperatures of storage in darkness 20 degrees C and 4 degrees C. The differences against the reference values (measured on the first day) were determined and evaluated in milk composition and characteristics as arising during milk storage. These differences were used in form of either cumulative means of differences (Figs. 1 to 5) or individual differences (Fig. 8). In the first part significant correlation coefficients (P less than 0.001) were calculated for the relationship between the variations of lactose content and the fat and protein contents: r = -0.59 and/or -0.73 (Figs. 6 and 7). This suggests that the decrease in the lactose content by 0.10% recorded by the infrared analysis and caused by lactose decomposition is accompanied by a "seeming" increase in the fat and protein content by about 0.04%. In the second part the correlation coefficients for the fat and protein contents r = -0.96 and -0.96 (P less than 0.001; Figs. 9 and 10; Tab. II) were calculated on the basis of an observation of the lactose decrease in an untreated milk sample (20 degrees C for 28 hours). These coefficients are somewhat different from the preceding ones; this is due to the lower homogeneity of the first set where the milk samples were treated in a different way, but the coefficients confirm the same conclusions. The values of the correlation coefficients for the dependence between the development of the acquired titratable acidity (SH) and the variations of fat (F), protein (P) and lactose (L) contents were as follows: r = 0.95; 0.95; -0.99 (P less than 0.001; Figs. 12, 13; Tab. II). Thus the above-mentioned "seeming" increase in the F and P contents can be explained to the extent of 92.2% from the decrease in the L content, which also causes the increase in titratable acidity to the extent of 98.0%.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[The effect of aging of milk samples on the accuracy of infrared analysis of milk composition]. 164 44

We have studied the mechanism by which liver Golgi apparatus maintains the acidity of its contents, using a subcellular fraction from rat liver highly enriched in Golgi marker enzymes. Proton accumulation (measured by quenching of acridine-orange fluorescence) and anion-dependent ATPase were characterized and compared. Maximal ATPase and proton accumulation required ATP; GTP and other nucleotides gave 10% to 30% of maximal activity. Among anions, Cl- and Br- approximately doubled the activities; others were much less effective. Half-maximal increase of ATPase and H+ uptake required 55 mmol/L and 27 mmol/L Cl-, respectively. In predominantly chloride media, SCN- and NO3- markedly inhibited H+ uptake. Nitrate competitively inhibited both the chloride-dependent ATPase (apparent Ki 6 mmol/L) and proton uptake (apparent Ki 2 mmol/L). Nitrate and SCN- also inhibited uptake of 36Cl. Replacing K+ with Na+ had no effect on the initial rate of proton uptake but somewhat reduced the steady state attained. Replacement of K+ with NH4+ and choline reduced proton uptake without affecting ATPase. The ATPase and H+ uptake were supported equally well by Mg2+ or Mn2+. The ATPase was competitively inhibited by 4-acetamido-4'-isothiocyano-stilbene-2,2'-disulfonic acid (apparent Ki 39 mumol/L). Other agents inhibiting both H+ uptake and ATPase were N-ethylmaleimide, N,N'-dicyclohexylcarbodiimide, chlorpromazine, diethylstilbestrol, Zn2+, Co2+ and Cu2+. In the Cl- medium, accumulated protons were released by ionophores at the relative rates, monensin = nigericin greater than valinomycin greater than carbonyl cyanide mchlorophenylhydrazone; the last of these also reduced ATPase activity. In the absence of Cl-, monensin and valinomycin both stimulated the ATPase. These results show a close association between ATPase activity and acidification of liver Golgi vesicles. They support a role for Cl- that depends on its uptake as a counter ion for H+ and suggest that it may also stimulate proton transport by a more direct effect on a component of the transport system.
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PMID:Proton accumulation and ATPase activity in Golgi apparatus-enriched vesicles from rat liver. 184 95

The use of an easily measured physiological change as a method of detecting the effect of toxic mine effluent (acidity, heavy metals) on a standard aquatic test organism was examined. Changes in whole body sodium concentration of Pimephales promelas after exposure for eight hours to mine water in the field were assessed as a physiological indicator of acid and metal pollution from coal mines. Static 96-h lethality tests were also performed in the laboratory in water collected from severely acidic (pH 3.49), moderately acidic (pH 4.65) and circumneutral (pH 6.25) mine effluent impacted streams as well as an artificially prepared (reconstituted) water (RMW) at three similar pH's (but lacking potentially toxic metals). This allowed comparison of the two assays in their sensitivity and ability to detect interactions between heavy metals and acidity. Exposure of P. promelas to severely acidic mine water caused the same mortality as exposure to RMW, although in the latter the fish died more rapidly (2 vs. 3 h); moderately acidic water was more toxic than RMW lacking metals. No mortality was observed in circumneutral mine water or corresponding RMW. Toxicity as estimated by changes in whole body sodium levels of P. promelas followed a pattern similar to toxicity as determined by the 96-h lethality tests. Exposures of P. promelas to moderately acidic mine water at two pHs and trace metals concentrations resulted in significantly different body sodium concentrations and net sodium efflux between groups of fish within six hours. The results suggest that the whole body sodium assay is a useful indicator of coal mine pollution.
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PMID:Use of whole body sodium loss from the fathead minnow (Pimephales promelas) as an indicator of acid and metal toxicity. 195 81


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