Showing papers on "Carbonic acid published in 1969"

Oceanic CO2 system: An evaluation of ten methods of investigation

Abstract: ABsTRAcr By combining two or more of the parameters pH, carbonate alkalinity, total carbon dioxide, and partial pressure of carbon dioxide, six equations can be obtained to express the concentration of carbonic acid that include molecular carbon dioxide, ten equations for bicarbonate ion, and eleven equations for carbonate ion concentrations. When the presentday analytical precision and the normal oceanic variances of the above four parameters are considered, the pH-partial pressure of carbon dioxide combination is the most promising to study the oceanic COz system.

Carbonic acid production and the role of carbonic anhydrase in decarboxylation in brain

Abstract: Sudden oxygenation of a thin film of rat brain homogenate, suspended between the surface of a glass pH-sensitive electrode and a gas-permeable membrane, is accompanied by a fall in pH, which is greater when carbonic anhydrase is inhibited. The result suggests that oxidative decarboxylation yields carbonic acid (HCO(3)- and H(+)), which dissociates to form molecular carbon dioxide. Brain carbonic anhydrase facilitates the formation of carbon dioxide from the decarboxylation products.

Acid-base relations in epithelium of turtle bladder: site of active step in acidification and role of metabolic CO2

Abstract: The acid-base relations across the two surfaces of the epithelium of the turtle bladder were examined. By means of the 5,5-dimethyl-2,4-oxazolidinedione (DMO) technique the intracellular OH- concentration was measured in the presence and absence of a transepithelial pH gradient. When both sides of the bladder were bathed with solutions free of exogenous CO2 and bicarbonate at pH 7.41 ([OH-] = 239 nmoles/liter), the epithelial cells were alkaline, the mean intracellular [OH-] being 347nmoles/liter. This alkalinity of the cells was preserved in bladders that secreted H+ against a gradient of over 2 pH units. In bathing solutions stirred with 4.85% CO2 and buffered with 25 mM HCO3- at pH 7.41 the intracellular [OH-] was lower than in CO2-free solutions and close to the extracellular [OH-]. In the CO2-free system anaerobiosis caused increased alkalinity of the cells and inhibition of H+ secretion presumably by decreased metabolic CO2 production. Carbonic acid inhibitors reduced H+ secretion, but had no significant effect on the alkalinity of the cells. An inactive analogue of acetazolamide had no effect on H+ secretion. The results indicate that the active step in acidification is located near the mucosal surface of the epithelium and that the alkali formed within the epithelial cells moves passively into the serosal solution along an electro-chemical gradient. The inhibitory effect of certain sulfonamides on H+ secretion by the bladder is directly correlated with their known carbonic anhydrase inhibitory activity, but not associated with a measurable change in the mean intracellular [OH-].

Preparation of millicurie quantities of oxygen‐15 labeled water

Abstract: Due to the annihilation radiation of the positron emitting oxygen-15, H215O has great potential for tracer studies. The method of preparation utilized the fast exchange reaction between carbon dioxide and carbonic acid. It was found that the rate of exchange depended on the temperature, the solution used and the dynamic state of the solution. Utilizing this exchange reaction, water with a specific activity of 80 mCi/cc was prepared.

Chlorophyll catalysis and einstein's law of photochemical equivalence in photosynthesis

Abstract: A B S T R A C T We describe the catalysis of photosynthesis by chlorophyll: (a) chlorophyll bound to carboniic acid (that is, the photolyte) absorbs 1 quantum of light and is thereupon split into oxygen, reduced carbonic acid, and free chlorophyll; (b) the photolyte (that is, chlorophyll bound to carbonic acid) is resynthesized from carbonic acid and free chlorophyll with the help of the energy derived from the reoxidation of two-thirds of the reduced carbon formed in the light reaction. For calculation of the true quantum requirement of photosynthesis from experimental measurements, it is necessary to measure the light absorbed by the photolyte only, since the light energy absorbed by free chlorophyll is not used in the oxygen development of photosynthesis. To eliminate the loss of the light absorbed by the free chlorophyll, the factor e = photolyte/total chlorophyll must be introduced into the calculation. Failure to take e into consideration has led to discrepancies of 1,000% between the quantum yields obtained in different laboratories. These discrepancies are now removed. The quantum requirement of the splitting of the photolyte is always 1.

The Effect of Acetazolamide upon Tissue Concentrations of Bicarbonate, Lactate, and Pyruvate in the Rat Brain

Abstract: The effect of various doses of acetazolamide upon acid-base parameters in brain tissue, cisternal CSF and arterial plasma was studied in rats, anesthetized with phenobarbital or nitrous oxide. The results confirmed older findings that carbonic anhydrase inhibition increases the CSF/plasma ratio for bicarbonate, and decreases the corresponding chloride ratio, and showed that the CSF pH remains unchanged during at least 6 hrs in spite of a marked plasma acidosis. The tissue bicarbonate was found to be significantly, but transiently, increased, and since the CSF bicarbonate was essentially unchanged, the increase in bicarbonate must have occurred in the intracellular phase, i.e. an alkaline shift in the cells. However, both the lactate and the pyruvate concentrations in the tissue were decreased after acetazolamide, suggesting an acidosis. It is discussed if these controversial findings indicate that caibonk anhydrase inhibition gives rise to a carbonic acid acidosis in the brain.

Acid-Base Relations in Epithelium of Turtle Bladder: Site of Active Step in Acidification and Role of Metabolic CO2

Abstract: A B S T R A C T The acid-base relations across the two surfaces of the epithelium of the turtle bladder were examined. By means of the 5,5-dimethyl-2,4-oxazolidinedione (DMO) technique the intracellular OH- concentration was measured in the presence and absence of a transepithelial pH gradient. When both sides of the bladder were bathed with solutions free of exogenous C02 and bicarbonate at pH 7.41 ([OH-] = 239 nmoles/liter), the epithelial cells were alkaline, the mean intracellular [OH-] being 347 nmoles/liter. This alkalinity of the cells was preserved in bladders that secreted H' against a gradient of over 2 pH units. In bathing solutions stirred with 4.85% CO2 and buffered with 25 mm HC03- at pH 7.41 the intracellular [OH-] was lower than in C02-free solutions and close to the extracellular [OH-]. In the C02-free system anaerobiosis caused increased alkalinity of the cells and inhibition of H' secretion presumably by decreased metabolic C02 production. Carbonic acid inhibitors reduced H' secretion, but had no significant effect on the alkalinity of the cells. An inactive analogue of acetazolamide had no effect on H+ secretion. The results indicate that the active step in acidification is located near the mucosal surface of the epithelium and that the alkali formed within the epithelial cells moves

Localization of the bicarbonate and carbonate pools by whole-body autoradiography.

Abstract: (5 figures) Analysis of individual tissues and body fluids for a substance of interest is the customary procedure for studying the relative concentration of a compound in the various tissues of the body. The disadvantage is that many small tissues or areas of a tissue may be unwittingly omitted from the dissection or sampling; some such areas could contain very high concentrations of the compound. The method of whole-body autoradiography described by ULLBERG (1958) allows the relative concentration of a radioactive substance to be determined in all the areas of the body. This is a report of a study of the distribution of bicarbonate in pregnant mice using this technique. The rapid equilibrium that is established in blood between bicarbonate, carbonate, carbonic acid, and carbon dioxide gas prevents distinction between these forms when any one of the four is the form in which the radioactive carbon is administered. In addition, any metabolic incorporation of any one of these into other molecules further complicates interpretation of the autoradiograms. However, since carbon dioxide is readily diffusible through cellular membranes, the pC0, is essentially uniform throughout the body. Any concentration gradients seen in whole-body autoradiograms after administration of one of the forms in equilibrium with bicarbonate will indicate gradients of concentration primarily of bicarbonate, carbonate, or incorporation of such into other molecules. At the pH of body fluids very little carbonate will exist. In the autoradiograms presented here, only bone and cartilage are considered to contain appreciable concentrations of the carbonate ion. In an earlier autoradiographic study of the distri

Benzyl amino carbamate substituted pyridines

Abstract: THERE ARE PREPARED PHARMACOLOGICAL COMPOUNDS OF THE FORMULA 2-((R5,R6,R7,R8,R9-PHENYL)-CH(-R4)-N(-R3)-),R1,R2-PYRIDINE AND THEIR PHARMACEUTICALLY ACCEPTABLE ACID ADDITION SALTS WHEREIN R1 IS AMINO, LOWER ALKYLAMINO, OR AMINO ACYLATED BY CARBONIC ACID, LOWER ALIPHATIC MONOESTERS OF CARBONIC ACID, AROMATIC MONOESTERS OF CARBONIC ACID, BENZOIC ACID, SUBSTITUTED BENZOIC ACID SATURATED OR UNSATURATED STRAIGHT OR BRANCHED CHAIN LOWER ALIPHATIC MONO OR DICARBOXYLIC ACIDS, CARBONIC ACID SEMI PORPHOLIDE OR CARBONIC ACID SEMI PIPERIDIDE, R2 IS HYDROGEN OR R1, R3 IS HYDROGEN, LOWER ALKYL OR ACYL AS DEFINED FOR R1, R5, R6, R7, R8 AND R9 ARE HYDROGEN, HALOGEN, ALKYL, TRIFLUOROMETHYL, HYDROXY, ALKOXY, HYDROXYLAKYL, ALIPHATIC ACYL, CARBOXY OR CARBOXYALKYL, R4 IS HYDROGEN, ALKYL OR (R''5,R''6,R''7,R''8,R''9-PHENYL)-ALK WHERE ALK IS A 1 TO 3 CARBON ATOM STRAIGHT OR BRANCH CHAIN ALKYLENE GROUP WHICH CAN BE SUBSTITUTED WITH HYDROXY, LOWER ALKYL, LOWER ALKOXY AND R''5, R''6, R''7, R''8 AND R''9 HAVE THE SAME MEANING AS R5, R6, R7, R8 AND R9, WHEN ALK IS UNSUBSTITUTED AT LEAST ONE OF R''5, R''6, R''7M R''8 OR R''9 IS NOT HYDROGEN AND IF R4 IS HYDROGEN OR ALKYL AT LEAST 3 OF R5, R6, R7, R8 AND R9 ARE NOT HYDROGEN. THE COMPOUNDS HAVE ANTIPHOGISTIC ANALGESTIC ACTIVITY.

Device for producing stimulated infrared emission, iraser, by means of an electric discharge in a gas mixture consisting partly of carbonic acid gas, and discharge tube destined for such a device

Abstract: The efficiency of an iraser with a discharge in carbonic acid, helium, nitrogen, and water vapor reduces after a few hundreds of hours. This is prevented by contacting the gas filling with a substance which contains water with the correct vapor pressure, and by ensuring the supply of water vapor which has disappeared by absorption in the wall and in the electrodes. A suitable material is, for example, zeolite.

Penicillin derivatives and their salts

Abstract: PENCILLINS HAVING THE FORMULA 2-(HOOC-),3,3-DI(CH3-),6-(R-O-C(=S)-S-C(-R1)(-R2)-CO-NH-) -PENAM ARE PREPARED BY REACTING 6-AMINOPENICILLANIC ACID OR ITS SALT WITH A SPECIFIC REACTIVE DERIVATIVE OF A CARBONIC ACID.

Factors affecting pH change in alkaline waste water treatment - I

Abstract: The pH of wastewater in various stages of its purification depends mainly upon the equilibria of carbonic acid. Thus relations between pH and the concentrations of carbon dioxide, bicarbonate and carbonate can be formulated. Corrections for the non-ideal character of the sewage are necessary. With some restrictions the concept of alkalinity can be used for these pH relations. Several (bio)chemical and physical processes occurring in biological purification affect the concentrations of carbon dioxide and (bi)carbonate. Processes studied are carbon dioxide desorption, oxidation of organic matter and nitrification. Models are proposed for the calculation of the effluent pH and the values so obtained are compared with the available experimental results.

Countercurrent Considerations Relating to Renal Medullary pCO2 and Bicarbonate Concentrations

Abstract: In mieropuneture samples from vasa rectum collecting duct, and the renal artery, pH, pCO2 and bicarbonate concentrations were determined.

Device for producing stimulated infrared emission,iraser,by means of an electric discharge in a gas mixture consisting at least partly of carbonic acid and discharge tube for such a divice

Abstract: An infrared laser employing a discharge in carbonic acid gas in a quartz tube, the electrodes consisting of platinum cylinders surrounding interruptions in the quartz tube.