Removal Rate Of Acid Research Articles

The Energetic and Nutritional Contribution of Glucose and Glycine Taken up from Natural Sea Water by Adult Marine Mussels

Abstract. The removal of glycine and glucose by freshly collected adult Mytilus edulis was determined using radiolabeled substances added to ambient concentrations of dissolved organic materials in freshly collected natural sea water. Uptake rates were calculated for substrate concentrations of 0.5 μM glycine and 1.0 μM glucose and were compared with the animals' energy and nitrogen demands as measured by oxygen consumption and ammonia excretion rates. Respiration and ammonia excretion rates as well as cither glycine or glucose removal were all determined for the same animals. The mean respiration rate was 670μl O2 g‐1h‐1, the mean ammonia excretion rate 1.95 μg‐at NH4‐g‐1 h‐1. The calculated uptake rates were 0.48 μmol ‐g‐1‐h‐1 for free amino acids and 0.44 μmol‐g‐1 h‐1 for free simple sugars. Such uptake rates could have contributed roughly 13% of the mussels' energy requirements or 10% of the mussels' nitrogen requirements assuming the following conditions: 0.5 μM concentration of free amino acids, 1.0μM concentration of simple sugars, uptake of total amino acids at a rate based on a weighted removal rate of glycine, alanine, serine, and glutamic acid, and uptake of simple sugars at a rate equal to that of glucose removal. It is apparent that simple organic substances dissolved in sea water may be of some benefit to mussels, especially when the substances occur in concentrations typical of coastal sea water.

Hepatic transport of bile acids in the isolated perfused rat liver

We studied the transport kinetics of a series of bile acids from blood to bile in the isolated perfused rat liver in order to define better the relationship between chemical structure of bile acid molecules and efficiency of the overall hepatic transport process. BA studied were taurocholate (TC), glycocholate (GC), cholate (C), tauroursodeoxycholate (TUDC), ursodeoxycholate (UDC) and hyodeoxycholate (HDC). Estimates of intrinsic hepatic clearance (Cl int), maximal secretory rate ( V max) were provided from the analysis of the relationship between bile acid removal rates and sinusoidal concentration under steady-state conditions. TC and TUDC had the highest Cl int (about 5 ml/min/g liver) and V max (about 800 nmol/min/g liver) followed in order by GC (1.71 ml/min/g liver; 442 nmol/min/g liver); C (1.25 ml/min/g liver; 252 nmol/min/g liver); HDC (0.86 ml/min/g liver; 238 nmol/min/g liver); UDC (0.72 ml/min/g liver; 176 nmol/min/g liver). The findings suggest that the efficiency of the overall hepatic transport of bile acids is highly dependent on their molecular structure and that conjugation has a more important effect on both CI int, and V max that the number or position of hydroxyl groups.

Lactic acid removal and heart rate frequencies during recovery after strenuous rowing exercise.

Three tests were conducted to assess the effectiveness of three different intensities of exercise both in reducing blood lactic acid (LA) levels and in influencing subjects' heart rate (HR), following a 2000 m race in a rowing boat. In the first and second tests these variables were investigated during a 13 min recovery exercise at 60% and 40% of the preceding maximum rowing speed respectively. In the third test the subjects had a resting recovery. The results include a significant increase (P less than 0.001) in the rate of lactate removal following the 40% recovery compared with the 60% and resting recoveries. The HRs were significantly lower during the last minute of resting recovery compared with 40% and 60% recoveries (P less than 0.001). The same was true when 40% recovery was compared with 60% recovery (P less than 0.001). The present data suggest firstly that 40% of the maximum rowing speed is an appropriate pace for effective LA removal and secondly that, at least for trained rowers, 86% of their maximum HR can be taken as an indication of work of an intensity at or above anaerobic threshold.

High-performance liquid chromatographic analysis of guanidino compounds using ninhydrin reagent : II. Guanidino compounds in blood of patients on haemodialysis therapy

An automated high-performance liquid chromatographic method using alkali-ninhydrin reagent for the post-column derivatization of guanidines has been developed. This procedure was applied to measurements made before and after haemodialysis. Among the guanidino compounds found in human blood, methylguanidine showed the lowest removal rate. The removal rate of guanidinosuccinic acid correlated with the plasma α 1-globulin fraction. The removal rate of each guanidino compound decreased with the period of dialysis.

急性腎不全の血液浄化法モデルによる尿毒症毒性物質の除去に関する実験的研究

This study was undertaken to examine the removal rate of guanidino compounds (GS) as uremic toxin in the small animal models of acute renal failure (ARF) undergoing hemodialysis. For this purpose, the methodological trial of hemodialysis was done to determine the clearance and removal rate of solutes, ultrafiltration rate and pressure in vitro, and extracorporeal blood flow in vivo. The mean removal rate of methylguanidine (MG) and guanidinosuccinic acid (GSA) was 33.8% and 56.0% respectively. Correlation was only observed between GSA and creatinine, GSA and arginine. But MG was not correlated with other GC. These results indicate that MG and GSA are important indicators to start hemodialysis and to understand metabolic disorder in ARF.

Uric acid metabolism in normal subjects and in gouty patients by chromatographic measurement of 14C-uric acid in plasma and urine

The turnover kinetics of uric acid were determined in a group of 25 subjects, including 6 controls, 17 gouty patients, and 2 subjects with asymptomatic hyperuricemia. According to their daily urate excretion while on a purine-free diet, the gouty patients (none of whom had evidence of tophi at the time of the study) were classified as follows: five overexcretor patients (“metabolic” gout), six normo-excretor patients (“renal” gout), and six borderline patients. Uric acid-2- 14C was used as the tracer, and the uric acid radioactivity in plasma and urine samples was measured after column chromatography through a polyacrylamide gel that specifically adsorbs uric acid. The experimental data of plasma disappearance curves and urine radioactivities of 14C-uric acid (followed up to 3 days after injection) were analyzed by the noncompartmental approach and by the urine/plasma ratio method, in order to calculate the total removal rate of uric acid, its distribution volumes, and the removal rate of uric acid through the renal route. The monocompartmental approach and the urine specific radioactivity methods were also employed to compute the uric acid turnover data, and the results were compared with those of noncompartmental analysis. The overexcretor patients were found to have normal metabolic clearance rate and fractional catabolic rate values, but significantly higher-than-normal total turnover rate values ( p < 0.005), whereas the normo-excretors had normal total turnover rate values but significantly lower metabolic clearance rate and fractional catabolic rate values compared to the controls ( p < 0.001). Uric acid excretion through the kidneys was found to be about two-thirds of the total removal both in the control subjects and in the gouty patients. The results obtained allowed the exclusion of any significant delay in the excretion of uric acid through the kidneys. The use of monocompartmental analysis led to a significant overestimation of both the total turnover rate ( p < 0.005) and the total pool of uric acid ( p < 0.001), and the urine specific radioactivity approach implied a significant overestimation of the total turnover rate ( p < 0.001). The gouty patients as a whole had a significantly larger-than-normal ( p < 0.001) total pool of uric acid, however determined. On the basis of the results obtained, a metabolic differentiation was made possible for the two pathophysiologic types of gout. In fact, the metabolic gout patients were all characterized by normal metabolic clearance rate values and increased total pool values, whereas the renal gout patients were all characterized by reduced metabolic clearance rate values and increased total pool values.

Continuous Removal of Lactic Acid from Wastewater by Candida utilis

Under steady-state conditions, the maximum rate of lactic acid removal was found to be 588 mg/h per liter of continuous culture.

Removal of fatty acid labelled cholesterol ester, phospholipid and triglyceride from atherosclerotic rabbit aorta in vitro

An organ culture technique was used to investigate the removal of fatty acids incorporated into various lipid fractions in intimal segments of atherosclerotic rabbit aorta. Segments of aorta were pulse-labelled in vitro with [9,10- 3H]-oleic acid and [1- 14C]linoleic acid for 24 h. The incubation medium was replaced with non-radioactive medium and the removal of the endogenously labelled phospholipid, triglyceride and cholesterol ester was followed for a further period of 10 days. Fatty acids incorporated into phospholipid and triglyceride were removed rapidly from the aortic intima, with fractional half-times of 4–5 days. Cholesterol ester fatty acids were removed more slowly from the aortic intima with fractional half-times of 9–12 days. When the removal rate of oleic acid incorporated into phospholipid, triglyceride and cholesterol ester was compared with that of linoleic acid incorporated into the same lipid fractions, no difference between removal of the two fatty acids could be detected with respect to any of the 3 lipid fractions.

Lactic acid removal rates during controlled and uncontrolled recovery exercise.

After a standardized 6-min bicycle ergometer exercise (89% VO2max) lactic acid removal rates were compared during recovery at rest and exercies at 29.7, 45.3, 61.8, and 80.8% VO2max, and twice while the subjects (N = 7) regulated their own recovery exercise. Blood samples were taken after the standardized exercise and every 5 min during the 30-min recovery periods. During the controlled recovery periods lactic acid removal rates were dependent on the intensity of the recovery (Y' = 0.103 + 0.218chi - 0.464 X 10(-2)chi2 + 0.252 X 10(-4)chi3). Optimal removal was predicted to occur at 32% VO2max. Removal rates during the self-regulated recoveries were not different (P greater than 0.05), but these removal rates were faster than during recovery at rest and exercise at 61.8 and 80.8% VO2max (P less than 0.01). Removal rates during the self-regulated recovery and recovery at 29.7 and 45.3% VO2max were not different (P greater than 0.05). The subjects were therefore able to remove lactic acid effectively when selecting their own recovery exercise.

The rate of lactic acid removal in relation to different baselines of recovery exercise.

During strenuous exercise lactic acid (LA) appears in the blood as a result of anaerobic metabolism. The rate at which this LA was removed from the blood after exercise was seen to increase to a maximum with a certain level of post exercise activity. This maximum rate of removal of LA appears to be at approximately 40% of the individual's maximum oxygen uptake when the exercise is performed on a bicycle ergometer.

The rate of acid removal by liquid ion exchangers

The rate of acid removal by liquid ion exchangers

Muscular exercise, lactic acid, and the supply and utilisation of oxygen.—Part XIV. The relation in man between the oxygen intake during exercise and the lactic acid content of the muscles

Hartree and A. V. Hill (1) have shown in the isolated frog’s muscle that the maximum rate of the recovery heat-production is proportional to the square of the total initial heat liberated by the stimulus. This relation has been amply confirmed by Hartree, in experiments hitherto unpublished on the isolated muscle of the tortoise. Hartree and Hill concluded that the speed of the recovery oxidation is at any moment proportional to the square of the concentration of the reacting bodies present at that moment, and suggested that a bimolecular reaction of some kind, possibly involving two lactic acid molecules, might be the determining agent in the velocity of the recovery oxidation. Up to the present it has not been shown that any substances other than lactic acid and oxygen are directly concerned in the recovery process in muscle, so the above relationship can be put in terms of these substances. Expressed in a formula, (rate of oxidation) ∝ (rate of lactic acid removal) =k(concentration of lactic acid)2, wherekis a velocity constant. In a recent paper Meyerhof, Lohmann and Meier (2) have shown that isolated frog’s muscle perfused by, or suspended in, an oxygenated Ringer’s solution containing sodium lactate will cause a diminution in the amount of lactate in the perfusing fluid, with an uptake of oxygen and a synthesis of glycogen. In these experiments it was obvious that the lactate ion was the determining factor in exciting the oxidation by which the energy was supplied to effect the synthesis of the glycogen. Moreover, as Hartree and Hill have shown (3), a rise of hydrogen ion concentration alone does not increase, but rather decreases, the speed of the recovery process in muscle. It seemed obvious, therefore, that the lactate ion itself was to be regarded as the governing factor in the speed of oxidation.