Infusion Of Amino Acid Solution Research Articles

Effects of Parenteral Infusion of Amino Acid Solutions in Acid-Base Balance in Patients with Advanced Chronic Renal Failure

Malnutrition is a very common condition in patients with chronic kidney disease (CKD), especially after the 3rd stage (GFR 30-59 mL/min/1.73 m2). It affects virtually every organ and the function of the entire organism as well and therefore influences the survival. Moreover, the supplementation of amino acids could correct the negative nitrogen balance of those patients improving their survival rates, while little is known regarding any possible negative effect of this supplementation of amino acids on the acid-base balance. We investigated the impact of parenteral infusion of two different kinds of amino acid solutions (specific for CKD patients and nonspecific) in 25 patients (12F, 13M), suffered from chronic renal failure in stages 3 and 4 (GFR 16 to 45.1 mL/min/1.73 m2). The specific for uremic CKD patients solution A was administrated for 5 days, and after an interval of one week, we treated the same patients for another 5 days with the second non-specific solution B, with usual composition), in order to investigate their influence on patients’ acid-base balance. Comparing the results of the first and the last infusion of solution A, neither pH nor blood gases analysis presented significant differences, while solution B induced statistically significant changes in both pH and blood gases, (p=0.0001). Acidosis was resulted in by the reduction of serum levels of HCO3 - whereas not any significant change observed in serum lactate levels after the infusion of each solution. These results suggest that for patients with chronic kidney disease in stages 3 and 4 who require the administration of a supplementary amino acid solution, the CKD-specific solution A may be preferred, since it prevents the worsen of the metabolic acidosis, which is commonly present in these patients.

Setting the “Furnace” during Anesthesia

Setting the “Furnace” during Anesthesia

Cerebral interstitial levels of glutamate and glutamine after intravenous administration of nutritional amino acids in neurointensive care patients

After severe trauma or disease glutamine (GLN) is mobilised from all muscles, including the heart and smooth muscles. The result is weakness and fatigue which affects recovery. The breakdown of muscle tissue can be counteracted by external GLN supply. There are concerns, however, that increasing the blood glutamine (Blood-GLN) concentration in patients with acute brain diseases is harmful by elevating the CNS interstitial (IS) concentration of glutamate (CNS-GLT), and that this may result in a secondary excitotoxic injury. We therefore studied the IS CNS-GLN and CNS-GLT when a commercially available nutritional amino acid solution was given intravenously. Ten NICU patients were included. The IS concentrations of amino acids in the brain were measured using intracerebral microdialysis. Blood concentrations of amino acids were measured before and after the amino acid infusion. The change in Blood-GLN was 2.14 (median; range 1.34–3.22) times the basal levels and Blood-GLT increased 1.37 (median; range 0.93–3.45) times basal levels. Both changes were statistically significant. The changes in CNS-GLN was 1.21 (median; range 0.72–1.92) and for CNS-GLT 0.96 (median; range 0.45–1.53) times the basal levels. This was statistically significant for CNS-GLN but not for CNS-GLT. A high initial CNS-GLT (55.3 μmol/l) in one patient increased even further to 84.4 μmol/l after infusion of amino acid solution. We submit that nutritional amino acid solutions can be administrated to some patients with acute brain disease without increasing the CNS-GLT values. However, since BBB function was not quantified in our study, further evaluation of this issue is warranted.

The effects of standard and branched chain amino acid enriched solutions on thermogenesis and energy expenditure in unconscious intensive care patients

Background & Aims: This study aims to compare the effects of standard and branched chain amino acid enriched solutions on thermogenesis and energy expenditure in unconscious and mechanically ventilated intensive care patients. Designs: The study was carried out at multidisciplinary intensive care unit. Twenty unconscious and mechanically ventilated patients (18–65 years of age) were included in the study. Patients were hemodynamically stable and all received continuous enteral nutrition. Energy expenditure was calculated using the Harris–Benedict Equation for all of the patients. Patients were randomly assigned to receive a 4 h infusion of 0.4 g/kg protein as amino acid solution. Group I ( n=10) received standard amino acid solution and group II ( n=10) received branched chain amino acid enriched solution. Energy expenditure, oxygen consumption and carbon dioxide production were measured by indirect calorimetric method every 30 min during the 4 h infusion period and 3 h thereafter. Rectal temperature was recorded concomitantly with the metabolic measurements throughout the study. Results: There was a statistically significant increase in body temperature during the infusion of amino acid solution between 30 and 210 min in group I and between 30 and 120 min in group II ( P<0.05). We observed a significant increase in energy expenditure at 30, 150, 180 and 210 min in group I and at 30–240 min in group II ( P<0.05). There were no differences between the two groups in terms of thermogenesis or energy expenditure values during the study ( P>0.05). Conclusion: Thermogenesis and energy expenditure values were increased during the parenteral infusion of both standard amino acid and branched chain amino acid enriched solutions in unconscious intensive care patients without any significance in between.

J004 Blood pressure and renal hemodynamics during infusion of amino acid solution or clonidine in different renal disease

J004 Blood pressure and renal hemodynamics during infusion of amino acid solution or clonidine in different renal disease

Efficacy of amino acid infusion for improving protein metabolism after surgery: a prospective randomized study in patients undergoing subtotal gastrectomy

Background: Appropriate regimens of peripheral parenteral nutrition (PPN) have been proposed for the improvement of protein metabolism after surgery. When evaluating the efficacy of administered nutrients, it is vital to consider the severity of surgical stresses to avoid confounding effects of the trauma on the postoperative metabolism. This study was designed to evaluate protein-sparing regimens through PPN in patients who had undergone subtotal gastrectomy. Study Design: Patients hospitalized at our institutes for gastric cancer were randomly divided into the following five groups and received PPN for 7 days after surgery: 1. G group (n = 9), 200 g glucose (per day); 2. AG group (n = 10), 54 g amino acids + 150 g glucose; 3. AGG group (n = 9), AG + 110 g glucose; 4. AGF group (n = 10), AG + 40 g fat; and 5. AGL group (n = 7), 58 g amino acids + 60 g glycerol. Biochemical studies were done before and after surgery. Results: In comparison to G group patients, AG group patients showed less negative cumulative nitrogen balances. No significant differences in cumulative nitrogen balances were observed between AGG, AGF, and AGL groups. Restoration of the reduced serum rapid turnover protein occurred earlier in the AGL group than in either the AGG or the AGF groups. Hyperglycemia, glucosuria, and hyperinsulinemia were prominent in the AGG group, and less prominent in the AGL group. Marked ketosis together with an increase in serum-free fatty acid levels was found in the AGL group. Conclusions: These results suggest that in patients who have undergone major elective surgery, infusion of amino acid solutions is advantageous for improving protein metabolism after surgery, and nonprotein energy source and intake are not essential when combined with amino acid solutions for improving nitrogen balance after surgery.

Biliary amino acid and glutathione secretion in response to amino acid infusion in the isolated rat liver.

The intravenous infusion of amino acid solutions has been associated with cholestatic liver injury in hospitalized patients and in laboratory animals. In the isolated rat liver, we recently showed that the acute decrease in bile flow, previously reported by other investigators, is dose related, reversible, and associated with dose-related increases in total biliary amino acid concentrations. In the present study, we characterized the effects of graded infusions of amino acid solutions, with and without taurocholate, on biliary secretion of individual amino acids and glutathione, an important regulator of bile flow. Livers from young adult male rats were perfused with an amino acid solution for 1 hour and allowed to recover for 30 minutes. Infusion of the amino acid solution was associated with dose-related increases in biliary concentrations of most amino acids included in the amino acid solution. Infusion of amino acid solutions resulted in a decreased bile/perfusate ratio of most amino acids, which were secreted into bile in amounts approximating their calculated uptake from the infusate. The inclusion of taurocholate in the infusate was associated with lower biliary concentrations of each individual amino acid and significant decreases in biliary total, reduced, and oxidized glutathione. Further investigation of the relationship between these changes in biliary amino acids and glutathione concentrations and the cholestasis associated with infusion of amino acid solutions may provide insights into the mechanism by which amino acids induce such cholestasis.

Amino acid infusions induce reversible, dose-related decreases in bile flow in the isolated rat liver.

Parenteral infusion of amino acid solutions is known to produce cholestasis in experimental animal models and in the isolated perfused rat liver. To characterize the dose responsiveness and reversibility of amino acid-induced cholestasis, isolated rat livers were perfused with solutions containing 1.5, 3.0, or 6.0 g of amino acids for 1 hour and allowed to recover for 30 minutes. Perfusion of livers resulted in a rapid, dose-related decrease in bile flow (p < .0001 at doses of 3.0 and 6.0 g). When the amino acid solution was discontinued, bile flow recovered to near control rates. Infusion of taurocholate reduced the magnitude of the decrease in bile flow associated with amino acid infusion but did not prevent it. Infusion of amino acid solutions was associated with the following changes in bile: (1) dose-related increases in total free amino acid concentrations; (2) increased osmolarity; (3) increased glucose concentrations; (4) increased potassium concentrations; (5) decreased chloride concentrations; (6) increased oxygen uptake in livers not perfused with added taurocholate; and (7) increased total bile acid concentrations in livers perfused with added taurocholate. Additional investigations are needed to determine whether these associations are attributable to individual amino acids or the total metabolic load of the amino acids.

An Animal Model for the Study of Amino Acid Metabolism in Uremia and during Peritoneal Dialysis

We tried to determine the suitability of the rabbit as an animal model to study amino acid (AA) metabolism in continuous ambulatory peritoneal dialysis. We also measured the effect of intraperitoneal (ip) infusion of AA on blood AA changes and food consumption. Plasma AA levels were measured in 10 normal rabbits after an overnight fasting and 30, 60, and 120 minutes after a meal. Following these baseline observations, rabbits were randomly divided into two groups. One group of five rabbits was made uremic after surgical partial nephrectomy, whereas the remaining (controls) underwent sham operations. Two weeks after the induction of uremia we measured the effect of chronic renal failure on fasting and postprandial (30, 60, 120 minutes) plasma AA levels. Upon the completion of the second experiment (4 weeks after the induction of uremia) we studied the effect of an ip AA on plasma AA profile 1, 2, 4, and 6 hours after the infusion in both uremic and control rabbits. We also measured the food intake in all experiments. The results of our experiments showed the following: 1. plasma AA in the rabbits decreased after induction of chronic renal failure and increased after food ingestion and ip infusion of AA solution; 2. neither induction of uremia nor ip AA infusion have an effect on food consumption; 3. the majority of the alterations in plasma AA levels we observed in the uremic rabbits were similar to those observed in humans, indicating that the rabbit may be a suitable model for the study of AA metabolism in chronic renal failure and during peritoneal dialysis.

Single-nephron responses to systemic administration of amino acids in dogs

It has been suggested that the tubuloglomerular feedback (TGF) system is responsible for renal vasodilation during systemic infusion of amino acid solutions. We evaluated the effect of intravenous administration of amino acids (serine, alanine, proline, and glycine; total dose of 0.075 mmol of amino acids.kg body wt-1.min-1) on whole kidney and single-nephron hemodynamics in pentobarbital sodium-anesthetized dogs. At spontaneous renal arterial pressure (RAP; 125.4 +/- 4.7 mmHg), measurements of single-nephron function obtained during tubular blockade, stop-flow pressure (SFP; 48.2 +/- 2.0 vs. 58.9 +/- 2.3 mmHg, P less than 0.01), and proximally determined single-nephron glomerular filtration rate (SNGFR-TPC; 73.9 +/- 7.0 vs. 93.4 +/- 7.6 nl/min, P less than 0.01) increased in parallel to the increases of outer cortical blood flow (OCBF; 15.4 +/- 1.1 vs. 19.1 +/- 1.5 units, P less than 0.05), renal blood flow (RBF; 4.60 +/- 0.18 vs. 5.73 +/- 0.22 ml.min-1.g kidney wt-1, P less than 0.01), and glomerular filtration rate (GFR; 0.885 +/- 0.034 vs. 1.116 +/- 0.034 ml.min-1.g kidney wt-1, P less than 0.01). Free-flow tubular fluid-to-plasma inulin ratios, determined from late proximal recollections during saline (control) and amino acid infusions failed to provide evidence for altered proximal reabsorption rate (1.63 +/- 0.12 vs. 1.58 +/- 0.17 during amino acids, NS). At reduced RAP (92.6 +/- 1.9 mmHg), where it is presumed that TGF-mediated vasodilation is already near maximal, the vasodilatory response to amino acid infusion was intact and single-nephron parameters measured during tubular blockade increased to the same extent as OCBF, RBF, and GFR.(ABSTRACT TRUNCATED AT 250 WORDS)

Kidney hemodynamics after ketone body and amino acid infusion in normal and IDDM subjects.

Little information is available on the hemodynamic response (renal reserve) of the diabetic kidney during an acute amino acid infusion, which has been shown to increase glomerular filtration rate (GFR) in normal humans. We recently found that the infusion of ketone bodies is able to raise GFR in both normal subjects and insulin-dependent diabetes mellitus (IDDM) patients. The aim of this study was to evaluate the renal reserve in 15 IDDM patients with a duration of diabetes of greater than 9 yr [8 with albumin excretion rate less than 15 micrograms/min (group 1) and 7 with albumin excretion rate greater than 100 micrograms/min (group 2)] and in 8 normal subjects during amino acid infusion (33 mumol.kg-1.min-1, Travasol 10% wt/vol solution containing 0.154 mM sodium chloride concentration; Travenol, Savage, MD) and during acetoacetic sodium salt (25 mumol.kg-1.min-1) infusion. Blood glucose was clamped at euglycemic levels. The infusion of sodium acetoacetate resulted in a 10- to 15-fold increase in circulating concentrations of ketone bodies, which were similar in magnitude in normal subjects and diabetic patients. The GFR peak increase above baseline after sodium acetoacetate infusion was 28% in normal subjects and 27% in group 1 and 19% in group 2 diabetic patients. The infusion of amino acid solution produced a three- to fivefold increase in plasma concentrations of amino acids in both normal subjects and diabetic patients. The GFR peak increase above baseline after amino acid infusion was significantly lower in diabetic patients (IDDM group 1: 5%, P less than .01; IDDM group 2: 6%, P less than .01) than in normal subjects (38%).(ABSTRACT TRUNCATED AT 250 WORDS)

Nitrogen Sources for Parenteral Nutrition in the Newborn Infant

Protein requirements for the preterm and term infant have been determined by a variety of methods. The parenteral protein needs of the very low birth weight infant are around 3 gm/kg/day and of the term infant approximately 2.2 gm/kg/day for maintenance of normal growth. These values are averages and may need to be modified for individuals depending upon a variety of potentially complicating factors. In this regard, many neonatologists recommend the provision of a maximum of 2 to 2.5 gm/kg/day of protein to newborns under most clinical situations. Whereas excessive administration of protein may result in adverse consequences, the tolerance of young infants to infusion of amino acid solutions is not well defined. Based upon animal studies of fetal amino acid utilization, the preterm infant may be capable of appropriately modifying its supply of amino acids over a relatively broad concentration range. It would appear that the supply of individual amino acids is adequately met by a number of amino acid solutions. The newer preparations appear to be more ideally suited to the special needs of the very low birth weight.

無麻酔，無拘束下におけるイヌの脳波記録法 特に肝性脳症研究への応用

We established a novel method to record canine electroencephalogram (EEG) under non-anesthesia and non-restraint condition, and applied to the studies of hepatic encephalopathy (H.E.). Beagles were trained every day laying quietly in a sealed box for not less than 2 hours for 2 weeks. The trained beagles were undertaken portcaval anastomosis operation (PCA), and their EEGs were recorded every day at fixed time. Slow wave appeared stably and dominantly within one month after PCA. In accordance with the changes in their EEGs, characteristic changes similar to patients with H.E. in blood chemistry and aminograms were observed. The deteriorated EEGs were normarized rapidly by the infusion of amino acid solution a specifically formulated for liver failure (THF), and this beneficial effect was retained even one hour after the end of the infusion. Those results suggest that the novel method may be useful for evaluating the effects of amino acid infusions on canine normal or abnormal EEGs.

Comparison of the olfactory response to amino acids in rainbow trout, brook trout, and whitefish

1. 1. The olfactory apparatus and the bulbar electrical responses induced by nasal infusion of amino acid solutions were compared among three salmonid species, rainbow trout, brook trout and whitefish. 2. 2. Morphology of the olfactory organ was similar in all species examined, except that the peripherial olfactory organ of whitefish was slightly smaller. 3. 3. The threshold concentration for the most effective amino acids ranged from 10 −7 to 10 −8 M in rainbow and brook trout and was higher in whitefish. 4. 4. Olfactory bulbar response spectra to amino acids were similar in all species. However, correlation was slightly higher between rainbow and brook trout ( r = 0·89) than between rainbow trout and whitefish ( r = 0·82).

The influence of synthetic amino acid and casein hydrolysate on the endogenous production and urinary excretion of acid in total intravenous alimentation.

Extract: These investigations are designed to quantitate the acidogenic properties of several commonly used amino acid solutions. Infusion of amino acid solutions causes a rise in the sulfuric acid production to a rate of 26.8–93.1 μEq/min/1.73 m2, which is a 4− to 14-fold increase over the preinfusion rate of 6.6 μEq/min/1.73 m2. This is a reflection of the amount of sulfur-containing amino acids in the infusate; it is lower with the casein hydrolysate than with the synthetic amino acid. The increase in is also significantly less with the 2.13% solutions than with the 4.25% solutions. The rate of organic acid production (H+oa) tends to be higher with the 4.25% casein hydrolysate (48.1 μEq/min/1.73 m2) than with both the 2.13% and the 4.25% synthetic amino acid solutions (22.4–29.3 μEq/min/1.73 m2). The latter value is not significantly different from the preinfusion rate of H+oa (20.4 μEq/min/1.73 m2). However, taken together, the results of these data are consistent with the view that the total amount of acid produced ( plus H+oa) in association with infusion of the synthetic amino acid solutions is proportionately higher than that associated with infusion of the casein hydrolysate. The absolute values for the acid excretion during amino acid infusions also show differences from the preinfusion state of 23.7 μEq/min/1.73 m2. The net acid excretion increased nearly four times during the infusion of the 4.25% synthetic, amino acid and casein hydrolysate solutions. The net acid excretion is shown to be linearly correlated with the net acid production (r = 0.974). On the other hand, only 65% of net acid production is excreted as net acid by the kidneys, and the extracellular buffering can account for only a fraction of the difference between the net acid production and excretion. These studies also provide the first conclusive evidence that the rate of endogenous acid production during glucose-water infusion is 26.9 μEq/min/1.73 m2 or 2–3 mEq/kg/24 hr. Speculation: The data presented suggest that the marked increase in endogenous acid production is related to the quantity and quality of amino acid-sulfur in the different type of infusates used in total intravenous alimentation and further suggest a significant nonextracellular buffering mechanism (possibly the skeletal system).