scholarly journals Towards Further Verification of Physiologically-Based Kidney Models: Predictability of the Effects of Urine-Flow and Urine-pH on Renal Clearance

2018 ◽  
Vol 368 (2) ◽  
pp. 157-168 ◽  
Author(s):  
Takanobu Matsuzaki ◽  
Daniel Scotcher ◽  
Adam S. Darwich ◽  
Aleksandra Galetin ◽  
Amin Rostami-Hodjegan
Keyword(s):  
Renal Clearance ◽  
Urine Flow ◽  
Urine Ph ◽  
Physiologically Based

The Excretion of Salicylate in Salicylate Poisoning

1971 ◽  
Vol 41 (5) ◽  
pp. 475-484 ◽  
Author(s):  
A. G. Morgan ◽  
A. Polak
Keyword(s):  
Sodium Bicarbonate ◽  
Renal Clearance ◽  
Sodium Lactate ◽  
Urine Flow ◽  
The Other ◽  
Urine Ph ◽  
Salicylate Poisoning ◽  
Toxic Concentrations ◽  
The Relationship

1. The renal clearance of salicylate has been measured in two groups of patients undergoing treatment by alkaline diuresis for salicylate poisoning. One group received mannitol and sodium lactate, the other acetazolamide and sodium bicarbonate. 2. The relationship between urine pH and salicylate clearance was found to be the same in both groups and similar to that shown at non-toxic concentrations in the blood by previous workers. 3. The influence of the rate of urine flow on the relationship between salicylate clearance and urine pH was also shown to be similar to that found at non-toxic concentrations in the blood.

Studies on the carbohydrate metabolism of sheep. XVI. Partition of ketone bodies in blood, tissues, and urine

1962 ◽  
Vol 13 (2) ◽  
pp. 307 ◽  
Author(s):  
RL Reid
Keyword(s):  
Renal Clearance ◽  
Blood Level ◽  
Ketone Bodies ◽  
Urine Flow ◽  
Blood Levels ◽  
Renal Tubules ◽  
Hydroxybutyric Acid ◽  
Acetoacetic Acid ◽  
Tissue Concentrations ◽  
Blood Concentrations

Acetone comprised 0–40% (average 18%) of the acetoacetic acid plus acetone fraction in sheep blood, in which the level of this fraction was 0.6–5.2 mg % (as acetone). Acetoacetic acid was largely converted to acetone during storage of blood at –20°C, with intermittent thawing for analysis. Concentrations of acetoacetic acid in red cells were similar to those in plasma, but those of ß-hydroxybutyric acid were considerably lower. In contrast to acetoacetic acid, ß-hydroxybutyric acid was virtually absent from foetal blood and from brain tissue. Concentrations of both ketone fractions in liver and muscle tissue were about one-half the blood concentrations. The renal clearance of acetoacetic acid plus acetone in hyperketonaemic pregnant ewes was independent of blood level up to 20 mg % and was little affected by rate of urine flow. Clearance values were in the range of 4–9 ml per min, which indicates that most of the acetoacetic acid filtered at the glomeruli is absorbed by the renal tubules. Renal clearance of ß-hydroxybutyric acid was dependent on blood level and was more affected by rate of urine flow than that of acetoacetic acid. Very little ß-hydroxybutyric acid appeared in the urine when blood levels were below 15 mg %. Clearance increased as blood concentration rose above this level, and reached maximum values, mostly of 3–5 ml per min, at blood levels exceeding 30 mg %.

scholarly journals Update on the drug-food interactions

2014 ◽  
Vol 1 (2) ◽  
pp. 100-106
Author(s):  
Hafid Bahri ◽  
◽  
Abdelkader Douaoui ◽  
Moufida Gharbi ◽  
Djamila Amroun
Keyword(s):  
Drug Interactions ◽  
Renal Clearance ◽  
Enzyme Inhibitor ◽  
Plasma Concentrations ◽  
Public Health Problem ◽  
Therapeutic Index ◽  
Major Public Health Problem ◽  
Urine Ph ◽  
Pharmacodynamic Interaction ◽  
The Impact

Drug interactions are a major public health problem, which partly attributed to some 10,000 deaths/year in Canada. Besides the interactions between two drugs, drug interactions are also due to the effect of other substances such as foods or nutrients. The drug-food interaction will be pharmacokinetic (affecting the absorption, distribution, metabolism, and elimination) or pharmacodynamic interaction. It is in the intestine that food may have the greatest impact with mainly a change in the amount of drugs absorbed that may be clinically significant for some drugs with narrow therapeutic index (cyclosporine, phenytoin, theophylline, etc.). The absorption of the drug in the presence of food will be determined by the particular physicochemical properties of the drug but also by the impact of food on one of the parameters determining the absorption such as: modified gastric acidity and emptying, the fat content of the food, the use of common transport between the drug and nutrients, chemical reactions between elements and drugs. Fasting situations or malnutrition can affect the distribution of drugs by increasing the free drug fraction, involving sometimes the risk of overdose. Diet affects drug metabolism by changing the activity of cytochrome P450. Most often is described the increase by grapefruit juice (enzyme inhibitor) of plasma concentrations of some drugs (cyclosporine, some statins, and calcium antagonists). Other foods (garlic, smoked meats and fish, caffeine) may increase metabolism. Diet can influence two stages of renal clearance (glomerular filtration - tubular reabsorption) by modifying urine pH or renal clearance. Pharmacodynamic interactions are also monitored, especially foods rich in vitamin k or tyramine with antivitamins K or MAOIs. Finally, health professionals must mobilize against these interactions, including through patient information.

BICARBONATE EXCRETION DURING HYPOTHERMIA

1963 ◽  
Vol 41 (1) ◽  
pp. 91-96 ◽  
Author(s):  
G. S. Kanter ◽  
R. H. Lubinski ◽  
I. M. Mielens
Keyword(s):  
Rectal Temperature ◽  
Plasma Levels ◽  
Excretion Rate ◽  
Artificial Respiration ◽  
Urine Flow ◽  
Urine Ph ◽  
Urinary Ph ◽  
Arterial Ph

The investigation was designed to determine whether the renal loss of bicarbonate contributes significantly to the acidosis of hypothermia. The excretion of bicarbonate during hypothermia was studied in five infused (6% creatinine in saline at 0.4 ml/minute) and five non-infused dogs. All animals were anesthetized and artificial respiration was not used. The rectal temperature was gradually reduced to the 26–27 °C range by approximately 4 hours of exposure to ice packing. After control, clearance periods of 30 minutes' duration were conducted serially and continually through the experiment. There was no significant increase in bicarbonate excretion during hypothermia in the non-infused group. The urinary pH remained at control levels of about 6.2. The fall in arterial pH was not due to urinary bicarbonate loss. The urinary pH in the infused group, which had a higher urine flow, increased to pH 6.7 due to increased excretion of bicarbonate. The urine pH in three animals with highest urine flows in this latter group approached plasma levels. The excretion rate of bicarbonate in the infused group, however, was similarly insufficient to account for the decrease in arterial pH. The hypothermic kidney is quite effective in reabsorbing bicarbonate.

BICARBONATE EXCRETION DURING HYPOTHERMIA

1963 ◽  
Vol 41 (1) ◽  
pp. 91-96 ◽  
Author(s):  
G. S. Kanter ◽  
R. H. Lubinski ◽  
I. M. Mielens
Keyword(s):  
Rectal Temperature ◽  
Plasma Levels ◽  
Excretion Rate ◽  
Artificial Respiration ◽  
Urine Flow ◽  
Urine Ph ◽  
Urinary Ph ◽  
Arterial Ph

The investigation was designed to determine whether the renal loss of bicarbonate contributes significantly to the acidosis of hypothermia. The excretion of bicarbonate during hypothermia was studied in five infused (6% creatinine in saline at 0.4 ml/minute) and five non-infused dogs. All animals were anesthetized and artificial respiration was not used. The rectal temperature was gradually reduced to the 26–27 °C range by approximately 4 hours of exposure to ice packing. After control, clearance periods of 30 minutes' duration were conducted serially and continually through the experiment. There was no significant increase in bicarbonate excretion during hypothermia in the non-infused group. The urinary pH remained at control levels of about 6.2. The fall in arterial pH was not due to urinary bicarbonate loss. The urinary pH in the infused group, which had a higher urine flow, increased to pH 6.7 due to increased excretion of bicarbonate. The urine pH in three animals with highest urine flows in this latter group approached plasma levels. The excretion rate of bicarbonate in the infused group, however, was similarly insufficient to account for the decrease in arterial pH. The hypothermic kidney is quite effective in reabsorbing bicarbonate.

pCO2 in regulating ammonia excretion by renal tubules of dogs

1961 ◽  
Vol 200 (4) ◽  
pp. 881-884 ◽  
Author(s):  
Robert Cade ◽  
Robert J. Shalhoub ◽  
Klaus Hierholzer
Keyword(s):  
Intracellular Ph ◽  
Diffusion Theory ◽  
Ammonia Excretion ◽  
Respiratory Acidosis ◽  
Passive Diffusion ◽  
Urine Flow ◽  
Potassium Depletion ◽  
Renal Tubules ◽  
Urine Ph ◽  
Ammonia Transport

The importance of urine pH, urine flow, availability of substrate and activity of cellular enzymes on the production and excretion of ammonia have been investigated in several species. Little information concerning the effect of intracellular pH on ammonia excretion is available. To investigate this problem we have altered intracellular pH by inducing respiratory acidosis and alkalosis in dogs. An elevated pCO2 uniformly depresses excretion of ammonia while a fall in pCO2 is associated with increased ammonia excretion at any given urine pH. When animals are depleted of potassium, the degree of depression by 10% CO2 is far greater than in the same animals studied before potassium depletion. The data are interpreted in the context of the passive diffusion theory of ammonia transport.

Effect of Posture on Renal Lithium Clearance

1976 ◽  
Vol 51 (1) ◽  
pp. 103-105
Author(s):  
D. F. Smith ◽  
M. Shimizu
Keyword(s):  
Renal Clearance ◽  
Flow Rate ◽  
Urine Flow ◽  
Urine Flow Rate ◽  
Lithium Clearance ◽  
Healthy Men ◽  
The Subject ◽  
First Time ◽  
Sodium And Potassium ◽  
Lying Down

1. Renal lithium clearance in healthy men was elevated while the subject was reclining, decreased upon standing and increased upon lying down during 45–60 min tests. 2. Parallel changes in renal clearance of creatinine, sodium and potassium, and urine flow rate occurred in response to the changes in posture. 3. The findings demonstrate for the first time that posture is a factor that can influence lithium excretion. Control of posture during lithium excretion tests is recommended.

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