Part I. The Determination of Urinary Acidity

1928 ◽  
Vol 74 (306) ◽  
pp. 425-435 ◽  
Author(s):  
S. A. Mann ◽  
R. W. Morris ◽  
G. K. Rowe
Keyword(s):  
Mental Disorder ◽  
Urinary Excretion ◽  
Compensatory Mechanism ◽  
Acid Excretion ◽  
First Line ◽  
Acid Base ◽  
Chemical Effects ◽  
Renal Threshold ◽  
Image Position

The following is the first of a series of communications relating to urinary excretion in cases of mental disorder with special reference to acid excretion. In this paper it is proposed only to deal with the make-up of urinary acidity and the methods for the determination of the acid characters. It is well known that respiratory regulation constitutes the first line of defence against change of body reaction, and that the kidneys afford the second protection against alteration by variations in the acid-base ratio of the urine. It is also fully established that urinary acidity is dependent on the nature of diet ingested, but it is not so well recognized that the urinary reaction is also dependent on the adequacy of the respiratory compensatory mechanism, and it would appear that those interested in dietetics and chemical effects on urinary acidity have not appreciated sufficiently the significance of the physiological influences, and those concerned with the respiratory side have been apt to disregard the influence of diet. The organism promptly defends itself against alkalinity by the excretion of bicarbonate, whether the alkalinity be due to ingested alkali or excessive exhalation of acid (CO2), and this excretion of bicarbonate appears to be independent of any particular renal threshold for bicarbonate. The response of the organism to acidity, however, is a much longer process, and in this case the kidney compensation takes the form of retention of base by ammonium base production and the retention of bicarbonate by alteration of the ratio of mono- and dibasic phosphate excreted according to the equation—

Reference Intervals for 24-h Urinary Normetanephrine, Metanephrine, and 3-Methoxy-4-Hydroxymandelic Acid in Hypertensive Patients

1992 ◽  
Vol 38 (3) ◽  
pp. 416-420 ◽  
Author(s):  
V Kairisto ◽  
P Koskinen ◽  
K Mattila ◽  
J Puikkonen ◽  
A Virtanen ◽  
...  
Keyword(s):  
Urinary Excretion ◽  
Reference Intervals ◽  
Diagnostic Information ◽  
Acid Excretion ◽  
Hypertensive Patients ◽  
Additional Diagnostic Information ◽  
Excretion Rates ◽  
Age And Sex

Abstract The urinary excretion of normetanephrine, metanephrine, and 3-methoxy-4-hydroxymandelic acid was quantified by HPLC in hypertensive patients who were being routinely investigated for the exclusion of pheochromocytoma. The data were used to calculate reference intervals for these analytes. Age- and sex-specific 95% reference intervals for 24-h urinary excretion were as follows (mumol/24 h): normetanephrine in men ages 16-35 years (n = 17) 0.7-3.4, in men older than 35 years (n = 121) 0.8-5.1, in women ages 16-35 years (n = 41) 0.5-2.1, and in women older than 35 years (n = 144) 0.6-3.3 mumol/24 h; metanephrine in men (n = 138) 0.3-2.0, and in women (n = 185) 0.2-1.3; and 3-methoxy-4-hydroxymandelic acid in men (n = 142) 10-54, and in women (n = 184) 9-38. Normetanephrine or metanephrine excretion rates or both exceeded the proposed reference intervals in seven of the eight patients with pheochromocytoma. Determination of 3-methoxy-4-hydroxymandelic acid excretion did not yield any additional diagnostic information.

Urinary excretion of hippuric acid by man

1961 ◽  
Vol 16 (3) ◽  
pp. 553-556 ◽  
Author(s):  
Hsien Wu ◽  
Howard C. Elliott
Keyword(s):  
Renal Function ◽  
Renal Disease ◽  
Urinary Excretion ◽  
Hippuric Acid ◽  
Liver Pathology ◽  
Acid Excretion ◽  
First Order ◽  
Average Value ◽  
Hippuric Acid Excretion

A simplified scheme for interpretation of urinary hippuric acid excretion data in terms of consecutive irreversible first-order processes is presented. The rate of excretion of endogenous hippuric, uric, and glucuronic acids is constant under the conditions of the experiments. The average value for the excretion constant KE for exogenous hippuric acid has been determined to be 2.7 hr-1 (0.0452 min-1) for doses of sodium hippurate ranging from 1 to 4 mEq. The average Ks for synthesis of hippurate from benzoate is 10.5 hr-1 (0.175 min-1) for doses of sodium benzoate ranging from 1 to 4 mEq. Study of 17 patients with varying degrees of renal disease as confirmed by standard p-aminohippurate and inulin clearances indicates that the determination of KE may be of value in the study of renal function, particularly where standard clearance techniques are not available. Preliminary data indicate that Ks may be useful in the study of the delay in synthesis of hippurate from benzoate that has been observed in some cases of liver pathology. Submitted on August 29, 1960

Spectrophotometric study of the acid-base and optical properties of the 5-bromo and 5-chloro derivatives of 2-(2-pyridylazo)-5-(diethylamino)phenol (BrPADAP, ClPADAP) and their complexation equilibria with zinc(II) ions

1982 ◽  
Vol 47 (10) ◽  
pp. 2676-2691 ◽  
Author(s):  
Miroslav Macka ◽  
Vlastimil Kubáň
Keyword(s):  
Equilibrium Constants ◽  
Spectrophotometric Study ◽  
Graphical Analysis ◽  
Alkaline Media ◽  
Acid Base ◽  
Ethanol Medium ◽  
Triton X ◽  
Mixed Water ◽  
Derivatives Of

The optical and acid-base characteristics of BrPADAP and ClPADAP were studied in mixed water-ethanol and water-DMF media and in 10% ethanol medium in the presence of cationic, anionic and nonionic tensides. The composition, optical characteristics, molar absorption coefficients and equilibrium constants of the ML and ML2 complexes with zinc(II) ions were found by graphical analysis and numerical interpretation of the absorbance curves by the modified SQUAD-G program. Optimal conditions were found for the spectrophotometric determination of Zn(II) in the presence of 0.1% Triton X-100 or 1% Brij 35 in alkaline media with pH = 6.5-10. BrPADAP and ClPADAP are the most sensitive reagents (ε = 1.3-1.6 . 105 mmol-1 cm2 at 557 and 560 nm, respectively) for the determination of zinc with high colour contrast of the reaction (Δλ = 104 nm) and selectivity similar to that for the other N-heterocyclic azodyes (PAN, PAR, etc.).

Compartmental transfer of mercury released from amalgam

1997 ◽  
Vol 16 (11) ◽  
pp. 667-672 ◽  
Author(s):  
S. Halbach ◽  
L. Kremers ◽  
H. Willruth ◽  
A. Mehl ◽  
G. Welzl ◽  
...  
Keyword(s):  
Oral Cavity ◽  
Urinary Excretion ◽  
Total Mercury ◽  
Excretion Rate ◽  
Absorbed Dose ◽  
Correlation Coefficients ◽  
Urinary Excretion Rate ◽  
Amalgam Fillings

The number of amalgam-covered surfaces and the occlusal area of the fillings, the concentrations of total mercury in plasma, erythrocytes and urine, the urinary excretion rate, and the absorbed daily doses estimated by two separate methods from intra-oral Hg emission were determined in 29 volunteers with a low amalgam load. The transfer ofHg from the fillings via the oral cavity and blood to urinary excretion was evaluated by multiple correla tions between these variables. In addition, the combina tion of variables most representative of the entire compartmental transfer of amalgam Hg was determined. Urinary excretion (1), Hg concentration in plasma (2) and absorbed dose (3) were most closely correlated to each other, followed by correlations with the variables of the fillings (4). Correlation coefficients were 0.75 for variables 1 vs 2 and 2 vs 3, and 0.49 for variables 3 vs 4. It was concluded that variables 1-3 best reflected the transfer of mercury from amalgam fillings throughout the organism and that they were relatively insensitive to dietary mercury. The determination of total mercury in plasma and of its urinary excretion rate appears, under practical aspects, most suitable for the investigation of Hg uptake from amalgam.

Bicarbonate and CO2 transport across the skin of the leopard frog, Rana pipiens: effect of PGF2alpha

1997 ◽  
Vol 272 (2) ◽  
pp. R640-R647 ◽  
Author(s):  
O. A. Candia ◽  
T. Yorio
Keyword(s):  
Methodological Approach ◽  
Transport Processes ◽  
Leopard Frog ◽  
Bicarbonate Transport ◽  
Amphibian Skin ◽  
Acid Base ◽  
Reliable Determination ◽  
Net Flux ◽  
Unidirectional Fluxes

The amphibian skin represents an important organ for osmoregulation and, like the mammalian kidney, maintains acid-base balance by secreting protons or base. However, the lack of a reliable and accurate method to measure the contribution of unidirectional fluxes of HCO3- ions to this mechanism has been an obstacle for the determination of the role of bicarbonate in epithelial acid-base homeostasis. Recently, one of us developed a method that allows for the reliable determination of transepithelial fluxes of bicarbonate, and this method was applied to determine unidirectional fluxes of (14)CO2 and H(14)CO3 under a variety of conditions. We report that the combined CO2 and HCO3- mucosal-to-serosal flux under 5% CO2 was 40% larger than the opposing flux, giving a net flux in the mucosal-to-serosal direction. This net flux was inhibited by acetazolamide. In CO2-free conditions, there was no detectable net flux; however, acetazolamide and PGF(2alpha) attenuated the mucosal-to-serosal flux and established an apparent secretion of HCO3-. A model is presented that depicts twelve vectors or components to the CO2 plus HCO3- fluxes in the frog skin. This model can accurately reproduce the experimental values measured from unidirectional fluxes of CO2 and HCO3- under a variety of conditions and can explain the effects of PGF(2alpha) on unidirectional 14C-labeled fluxes as a consequence of inhibition of H+ secretion to the apical bath, similar to what was previously suggested by our laboratory using a different methodological approach. The present method, utilizing radiolabeled HCO3-, may be useful as a means to evaluate the mechanism of action of hormones and drugs that may regulate acid-base homeostasis by altering proton and bicarbonate transport processes.

Steroids and steroidases. IX. Activation parameters and the mechanism of base- and enzyme-catalyzed isomerizations of androst-5-ene-3,17-dione. The nature of the active center of the Δ5 → Δ4-3-ketosteroid isomerase of Pseudomonas testosteroni

1969 ◽  
Vol 47 (23) ◽  
pp. 4459-4466 ◽  
Author(s):  
J. Bryan Jones ◽  
Donald C. Wigfield
Keyword(s):  
Amino Acids ◽  
Active Center ◽  
Activation Parameters ◽  
Circumstantial Evidence ◽  
Kcal Mole ◽  
Acid Base ◽  
Ketosteroid Isomerase ◽  
Enzyme Action ◽  
Enthalpy Of Activation

Determination of the activation parameters for the acid-, base-, and enzyme-catalyzed isomerizations of androst-5-ene-3,17-dione has revealed that the facility of the enzymic process is mainly due to an extremely low enthalpy of activation of 5.0 kcal mole−1. Further circumstantial evidence regarding the nature of the reacting groups at the active center has also been obtained, and a mechanism of enzyme action is proposed employing tyrosine and histidine as the principal amino acids responsible for catalyzing the isomerization.

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