Calculation of variables describing plasma nonvolatile weak acids for use in the strong ion approach to acid-base balance in cattle

2002 ◽  
Vol 63 (4) ◽  
pp. 482-490 ◽  
Author(s):  
Peter D. Constable
Keyword(s):  
Weak Acids ◽  
Acid Base Balance ◽  
Acid Base ◽  
Base Balance

Modeling the effects of proteins on pH in plasma

1999 ◽  
Vol 86 (4) ◽  
pp. 1421-1427 ◽  
Author(s):  
Philip D. Watson
Keyword(s):  
Serum Albumin ◽  
Association Constant ◽  
Fixed Charge ◽  
Side Chain ◽  
Weak Acids ◽  
Acid Base Balance ◽  
Acid Base ◽  
Histidine Residues ◽  
Base Balance ◽  
Parameter Values

Stewart’s model of plasma acid-base balance ( Can. J. Physiol. Pharmacol. 61: 1444–1461, 1983) has three weaknesses in the treatment of weak acids: 1) the combination of all weak acids into one entity, 2) inappropriate chemistry for the protein combination with H+, and 3) undocumented values for the dissociation parameters. The present study models serum albumin acid-base properties by fixed negative charges and the association of H+ with the imidazole side chain of histidine. This model has three parameters: 1) the net negative fixed charge (21 eq/mol), 2) the number of histidine residues (16/mol), and 3) the association constant for the imidazole side chain (1.77 × 10−7 eq/l), all determined from published values. The model was compared with that of Figge, Mydosh, and Fencl ( J. Lab. Clin. Med.120: 713–719, 1992) and with the pH data of Figge, Rossing, and Fencl ( J. Lab. Clin. Med. 117: 453–467, 1991). The predictions of pH were excellent, comparable to those found by Figge, Mydosh, and Fencl. The model has the advantages that its structure and parameter values are supported by the literature and that the acid-base effects of factors modifying protein can be investigated.

scholarly journals Influence of Acid-Base Balance on Efficacy and Toxicity of Drugs

1965 ◽  
Vol 58 (11P2) ◽  
pp. 961-963 ◽  
Author(s):  
M D Milne
Keyword(s):  
Practical Importance ◽  
Physiological Property ◽  
Water Soluble ◽  
Weak Acids ◽  
Acid Base Balance ◽  
Acid Base ◽  
Urinary Ph ◽  
Alkaline Urine ◽  
Base Balance ◽  
Ph Dependent

Changes in acid-base balance have a profound influence on many aspects of the action of drugs. This is illustrated by data on the absorption of drugs from the stomach and intestine, in changes in distribution of drugs between plasma and cells, and the effect of change in urinary pH. As a general principle, these changes in the pharmacology of weak acids and bases are governed by physicochemical principles, which influence the proportion of the ionized and unionized components according to the pH of the medium and also to the peculiar property of biological membranes which allow the free passage of the lipoid-soluble unionized component and impede transfer of the water-soluble ionized fraction. Lipoid-soluble weak acids are excreted at higher clearances in alkaline urine, and conversely weak bases in acid urine. This is shown to be of practical importance in the treatment of poisoning, in the diagnosis of addiction to drugs and in studies of drug metabolism. In general, the excretion of natural metabolites is less likely to be influenced by urinary pH, as these substances are usually less lipoid-soluble than many widely used drugs. pH-dependent excretion is, however, of practical importance in relation to the urinary content of many indolic metabolites and also in the excretion of pigments derived from the degradation of hæmoglobin. Urobilinogen excretion is certainly pH-dependent, a higher clearance rate occurring in alkaline urine. However, work is necessary to decide whether some of the porphyrins also show this important physiological property.

Acid-Base Balance: Origin of Plasma [H+] During Exercise

1995 ◽  
Vol 20 (3) ◽  
pp. 341-356 ◽  
Author(s):  
John M. Kowalchuk ◽  
Barry W. Scheuermann
Keyword(s):  
Strong Ion Difference ◽  
Weak Acids ◽  
Acid Base Balance ◽  
Acid Base ◽  
Independent Variables ◽  
Electrical Neutrality ◽  
Dissociation Equilibrium ◽  
Dependent Variables ◽  
Base Balance ◽  
Physicochemical Approach

According to physicochemical principles, the plasma concentration of hydrogen ions ([H+]), bicarbonate ([HCO3−]), and other acid-base-dependent variables are determined by the plasma PCO2; the strong ion difference ([SID+] = Σ[strong cations] − Σ[strong anions]); and the concentration of weak acids ([ATOT] = [HA] + [A−]). The physicochemical interactions between the acid-base-independent and dependent variables must recognize the constraints imposed by the law of electrical neutrality, dissociation equilibrium of weak acids and water, and the conservation of mass. This review demonstrates the usefulness of the physicochemical approach in studying plasma acid-base control during progressive exercise to exhaustion where the work rate was increased as either a slow (8 W/min) or fast (65 W/min) ramp function. The factors contributing to changes in the concentration of the acid-base-independent variables, and the contribution of the acid-base-independent variables to the plasma [H+] and [HCO3−] during exercise, will be discussed. Key words: PCO2, strong ion difference, weak acids, lactate, potassium

Higher Dietary Acidity is Associated with Lower Bone Mineral Density in Postmenopausal Iranian Women, Independent of Dietary Calcium Intake

2014 ◽  
Vol 84 (3-4) ◽  
pp. 0206-0217 ◽  
Author(s):  
Seyedeh-Elaheh Shariati-Bafghi ◽  
Elaheh Nosrat-Mirshekarlou ◽  
Mohsen Karamati ◽  
Bahram Rashidkhani
Keyword(s):  
Calcium Intake ◽  
Dietary Calcium ◽  
Dietary Calcium Intake ◽  
Dietary Intakes ◽  
Iranian Women ◽  
Acid Base Balance ◽  
Mineral Density ◽  
Acid Base ◽  
Base Balance ◽  
Dietary Acid

Findings of studies on the link between dietary acid-base balance and bone mass are relatively mixed. We examined the association between dietary acid-base balance and bone mineral density (BMD) in a sample of Iranian women, hypothesizing that a higher dietary acidity would be inversely associated with BMD, even when dietary calcium intake is adequate. In this cross-sectional study, lumbar spine and femoral neck BMDs of 151 postmenopausal women aged 50 - 85 years were measured using dual-energy x-ray absorptiometry. Dietary intakes were assessed using a validated food frequency questionnaire. Renal net acid excretion (RNAE), an estimate of acid-base balance, was then calculated indirectly from the diet using the formulae of Remer (based on dietary intakes of protein, phosphorus, potassium, and magnesium; RNAERemer) and Frassetto (based on dietary intakes of protein and potassium; RNAEFrassetto), and was energy adjusted by the residual method. After adjusting for potential confounders, multivariable adjusted means of the lumbar spine BMD of women in the highest tertiles of RNAERemer and RNAEFrassetto were significantly lower than those in the lowest tertiles (for RNAERemer: mean difference -0.084 g/cm2; P=0.007 and for RNAEFrassetto: mean difference - 0.088 g/cm2; P=0.004). Similar results were observed in a subgroup analysis of subjects with dietary calcium intake of >800 mg/day. In conclusion, a higher RNAE (i. e. more dietary acidity), which is associated with greater intake of acid-generating foods and lower intake of alkali-generating foods, may be involved in deteriorating the bone health of postmenopausal Iranian women, even in the context of adequate dietary calcium intake.

The Effect of Long-term Topiramate Treatment on Acid-base Balance in Children with Epilepsy

2016 ◽  
Vol 24 (3) ◽  
pp. 116-121
Author(s):  
김지용 ◽  
남상욱 ◽  
김영미 ◽  
이윤진 ◽  
이훈상 ◽  
...  
Keyword(s):  
Acid Base Balance ◽  
Acid Base ◽  
Base Balance

scholarly journals THE ACID-BASE BALANCE DISTURBANCE OF PREGNANCY

1932 ◽  
Vol 98 (1) ◽  
pp. 253-260 ◽  
Author(s):  
Victor C. Myers ◽  
Edward Muntwyler ◽  
Arthur H. Bill
Keyword(s):  
Acid Base Balance ◽  
Acid Base ◽  
Base Balance
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