scholarly journals Impaired sensitivity to insulin of rat livers perfused with blood of diminished haematocrit

1980 ◽  
Vol 192 (1) ◽  
pp. 219-222 ◽  
Author(s):  
G B Storer ◽  
R P Trimble ◽  
D L Topping
Keyword(s):  
Amino Acids ◽  
Whole Blood ◽  
Bile Flow ◽  
Ketone Bodies ◽  
O2 Consumption ◽  
Rat Livers

1. In livers from fed rats perfused with homologous whole blood of a haematocrit value of 37%, insulin decreased the perfusate concentrations of glucose and amino acids, production of ketone bodies (3-hydroxybutyrate + acetoacetate) and increased bile flow. 2. Perfusion with blood diluted with buffer to a haematocrit value of 17% decreased hepatic O2 consumption by 40-50%. Perfusate concentrations of glucose and lactate, the rate of ketogenesis and the ratios [lactate]/[pyruvate] and [3-hydroxybutyrate]/[acetoacetate] were all increased. 3. In livers perfused with blood of diminished haematocrit, effects of insulin on perfusate glucose an amino acids, ketogenesis and bile flow were abolished.

scholarly journals PROTEIN SYNTHESIS IN THE PERFUSED RAT LIVER

1956 ◽  
Vol 39 (4) ◽  
pp. 567-583 ◽  
Author(s):  
David Jensen ◽  
Harold Tarver
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Bile Flow ◽  
Specific Activity ◽  
Reticuloendothelial System ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Rat Livers ◽  
New Protein

1. When the rat livers are perfused under the conditions of these experiments with rat blood diluted with saline, the livers remain capable of removing colloidal chromic phosphate normally for 4 hours or more; that is, the reticuloendothelial system continues to function normally. 2. Good rates of bile flow continue, generally for 4 hours. 3. The livers incorporate radioactivity from the amino acids methionine, lysine, and histidine at rapid rates for 1 or 2 hours. Thereafter the rates fall. 4. The specific activity of the free lysine and histidine in the perfusate falls rapidly during the experiments (to 25 or 35 per cent of its original value at 10 minutes). 5. The fall in rate of incorporation of radioactivity is attributable to the fall in amino acid specific activity. 6. Addition of a complete amino acid mixture to the perfusate does not appear to have any stimulatory effect on incorporation of radioactivity from labelled amino acids. 7. With lysine, on the assumption that incorporation is due to new protein formation, there is a rate of synthesis equivalent to 230 mg. of plasma protein per 100 gm. of rat per day. This result is in agreement with turnover data obtained from rats in vivo. 8. The results emphasize once again the importance of precursor specific activity in the interpretation of metabolic experiments with labelled amino acids.

scholarly journals Combined Effect of Arginine, Valine, and Serine on Exercise-Induced Fatigue in Healthy Volunteers: A Randomized, Double-Blinded, Placebo-Controlled Crossover Study

Nutrients ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 862 ◽  
Author(s):  
Yuichi Tsuda ◽  
Makoto Yamaguchi ◽  
Teruyuki Noma ◽  
Eiji Okaya ◽  
Hiroyuki Itoh
Keyword(s):  
Amino Acids ◽  
Healthy Volunteers ◽  
Perceived Exertion ◽  
Ketone Bodies ◽  
Blood Analysis ◽  
Rating Of Perceived Exertion ◽  
Physical Parameters ◽  
Positive Effects ◽  
Exercise Induced ◽  
Double Blinded

Although several kinds of amino acids (AAs) are known to affect physiological actions during exercise, little is known about the combined effects of a mixture of several AAs on fatigue during exercise. The aim of the present study was to investigate the effect of an AA mixture supplement containing arginine, valine, and serine on exercise-induced fatigue in healthy volunteers. These AAs were selected because they were expected to reduce fatigue during exercise by acting the positive effects synergistically. A randomized, double-blinded, placebo-controlled crossover trial was conducted. Thirty-nine males ingested an AA mixture containing 3600 mg of arginine, 2200 mg of valine, and 200 mg of serine or a placebo each day for 14 days. On the 14th day, the participants completed an exercise trial on a cycle ergometer at 50% of VO2max for 120 min. After the two-week washout period, the participants repeated the same trial with the other test sample. The participant’s feeling of fatigue based on a visual analog scale (VAS) and a rating of perceived exertion (RPE), as well as blood and physical parameters were evaluated. The feeling of fatigue based on VAS and RPE were significantly improved in AA compared to those in placebo. In the blood analysis, the increase in serum total ketone bodies during exercise and plasma tryptophan/branched-chain amino acids were significantly lower in AA than those in placebo. The present study demonstrated that supplementation with an AA mixture containing arginine, valine, and serine reduced the feeling of fatigue during exercise. The AA mixture also changed several blood parameters, which may contribute to the anti-fatigue effect.

scholarly journals Oxidative properties of carp red and white muscle

1989 ◽  
Vol 143 (1) ◽  
pp. 321-331 ◽  
Author(s):  
C. D. Moyes ◽  
L. T. Buck ◽  
P. W. Hochachka ◽  
R. K. Suarez
Keyword(s):  
Amino Acids ◽  
White Muscle ◽  
Citrate Synthase ◽  
Ketone Bodies ◽  
Redox Balance ◽  
Fatty Acyl ◽  
Oxidation Rates ◽  
Substrate Preferences ◽  
Glycerophosphate Dehydrogenase ◽  
Wide Range

Substrate preferences of isolated mitochondria and maximal enzyme activities were used to assess the oxidative capacities of red muscle (RM) and white muscle (WM) of carp (Cyprinus carpio). A 14-fold higher activity of citrate synthase (CS) in RM reflects the higher mitochondrial density in this tissue. RM mitochondria oxidize pyruvate and fatty acyl carnitines (8:O, 12:O, 16:O) at similarly high rates. WM mitochondria oxidize these fatty acyl carnitines at 35–70% the rate of pyruvate, depending on chain length. WM has only half the carnitine palmitoyl transferase/CS ratio of RM, but similar ratios of beta-hydroxyacyl CoA dehydrogenase/CS. Ketone bodies are poor substrates for mitochondria from both tissues. In both tissues mitochondrial alpha-glycerophosphate oxidation was minimal, and alpha-glycerophosphate dehydrogenase was present at low activities, suggesting the alpha-glycerophosphate shuttle is of minor significance in maintaining cytosolic redox balance in either tissue. The mitochondrial oxidation rates of other substrates relative to pyruvate are as follows: alpha-ketoglutarate 90% (RM and WM); glutamate 45% (WM) and 70% (RM); proline 20% (WM) and 45% (RM). Oxidation of neutral amino acids (serine, glycine, alanine, beta-alanine) was not consistently detectable. These data suggest that RM and WM differ in mitochondrial properties as well as mitochondrial abundance. Whereas RM mitochondria appear to be able to utilize a wide range of metabolic fuels (fatty acids, pyruvate, amino acids but not ketone bodies), WM mitochondria appear to be specialized to use pyruvate.

Effect of tauroursodeoxycholic acid on bile flow and calcium excretion in ischemia-reperfusion injury of rat livers

1995 ◽  
Vol 23 (5) ◽  
pp. 582-590 ◽  
Author(s):  
Takashi Ono ◽  
Naofumi Nagasue ◽  
Hitoshi Kohno ◽  
Masaaki Uchida ◽  
Yoshinari Takemoto ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Bile Flow ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Calcium Excretion ◽  
Tauroursodeoxycholic Acid ◽  
Rat Livers

Formation of hepatic lymph

1964 ◽  
Vol 207 (4) ◽  
pp. 877-882 ◽  
Author(s):  
J. S. Krebs ◽  
R. W. Brauer ◽  
J. L. Bollman ◽  
G. F. Leong
Keyword(s):  
Blood Plasma ◽  
Continuous Infusion ◽  
Extracellular Space ◽  
Bile Flow ◽  
The Other ◽  
Hepatic Cells ◽  
Rat Livers ◽  
In Blood Plasma

Samples of hepatic lymph collected from isolated perfused rat livers or from livers of whole rats, during continuous infusion of BSP, showed two types of response with respect to content of BSP. One of these was characterized by lymph BSP concentrations below those in blood plasma, and a chromatographic composition of lymph BSP different from that in both plasma and bile. In the other response BSP concentrations in lymph were grossly higher than those in plasma, and the chromatographic composition of the BSP was identical with that in bile. The second response was observed whenever bile flow was deliberately arrested, but it also occurred when bile was apparently flowing freely, suggesting that a type of nonobstructive, nonhemolytic jaundice could exist, based on failure of labile mechanisms which normally prevent diffusion of biliary substances into the extracellular space. The chromatographic composition of the BSP in responses of the first type suggests that part of the BSP in hepatic lymph normally arises from the hepatic cells, rather than from either the blood plasma or the bile.

Metabolic Effects of the Use of Protein-Sparing Infusions in Postoperative Patients

1980 ◽  
Vol 58 (6) ◽  
pp. 507-515 ◽  
Author(s):  
K. J. Foster ◽  
K. G. M. M. Alberti ◽  
C. Binder ◽  
Leslie Hinks ◽  
S. Karran ◽  
...  
Keyword(s):  
Amino Acids ◽  
Blood Glucose ◽  
Amino Acid ◽  
Total Nitrogen ◽  
Insulin Infusion ◽  
Ketone Bodies ◽  
Treated Group ◽  
Saline Infusion ◽  
Nitrogen Excretion ◽  
Protein Sparing

1. The mechanism of the purported protein-sparing effects of different postoperative intravenous regimens still remains controversial. We have therefore measured circulating concentrations of metabolites and hormones in blood and urine nitrogen excretion in patients receiving (a) sodium chloride solution (saline), (b) 1.5 g of glucose day−1 kg−1 body weight, (c) 1.5 g of glucose day−1 kg−1 with insulin (0.56 unit day−1 kg−1) or (d) mixed amino acids (1.5 g day−1 kg−1) after abdominal operation. 2. Compared with results for saline-treated patients, glucose infusion resulted in raised glucose and insulin concentrations and lowered ketone body and non-esterified fatty acid concentrations but did not influence protein catabolism. 3. Addition of insulin lowered blood glucose by approximately 1 mmol/l. Total nitrogen excretion during glucose/insulin infusion was significantly less than during saline infusion. 4. Infusion of amino acids, compared with saline infusion, resulted in raised blood glucose, alanine, serum insulin and plasma glucagon concentrations but lower concentrations of plasma non-esterified fatty acids and blood ketone bodies. Insulin concentrations, however, were similar in both amino acid- and glucose-treated groups. 5. Amino acid infusion increased urea and total nitrogen excretion but net nitrogen loss was only 1.9 mmol of nitrogen day−1 kg−1 compared with 12.7 mmol day−1 kg−1 in the saline-treated group and 11.0 mmol day−1 kg−1 in the glucose-treated group. 6. Glucose (and insulin) infusion appeared to inhibit gluconeogenesis, and amino acids to enhance it. The nitrogen-sparing effect of amino acids appears largely related to their mass and is apparently unrelated to changes in ketone bodies and insulin.

Structure-function relationships of peptide fragments of gastrin and cholecystokinin.

1977 ◽  
Vol 233 (4) ◽  
pp. E286
Author(s):  
D L Kaminski ◽  
M J Ruwart ◽  
M Jellinek
Keyword(s):  
Amino Acids ◽  
Structure Function ◽  
Bile Flow ◽  
Hydrogen Ion ◽  
Biliary System ◽  
Peptide Fragments ◽  
Hepatic Bile ◽  
Amino Acid Peptide ◽  
The Common ◽  
Active Fragments

This study evaluates the structure-function relationships of the C-terminal peptide fragments of gastrin and cholecystokinin (CCK) in the biliary system and the stomach. Dogs with chronic biliary and gastric fistulas were used. Administration of the common fragments of CCK and gastrin with four and five amino acids and the active fragments of CCK with six through eight amino acids without sulfation of tyrosine in position 7 failed to alter hepatic bile flow from control values while significantly stimulating gastric hydrogen ion output. Administration of the seven and eight amino acid peptide fragments of CCK with sulfation of tyrosine in position 7 significantly increased hepatic bile flow. Administration of the sulfated octapeptide with 4 microgram/kg per h of nonsulfated octapeptide did not result in the inhibition of the choleresis produced by the sulfated peptide. The gastric hydrogen ion response produced by the administration of the nonsulfated and sulfated peptide was equal to that of the nonsulfated peptide alone. These results suggest that in the biliary system the receptor is highly specific as sulfation of the peptide fragment of CCK is essential for combining with the receptor, whereas in the stomach the receptor has little specificity and combines with all of the peptide fragments evaluated.

Intracellular alkalinization stimulates bile flow and vesicular-mediated exocytosis in IPRL

1993 ◽  
Vol 265 (2) ◽  
pp. G347-G353 ◽  
Author(s):  
R. Bruck ◽  
A. Benedetti ◽  
M. Strazzabosco ◽  
J. L. Boyer
Keyword(s):  
Horseradish Peroxidase ◽  
Biliary Excretion ◽  
Bile Flow ◽  
Channel Blocker ◽  
Rat Hepatocytes ◽  
Disulfonic Acid ◽  
K Channel ◽  
Rat Livers ◽  
Intracellular Alkalinization ◽  
Stimulation Of

Intracellular pH recovery from an acute alkaline load in rat hepatocytes is mediated by a Cl(-)-HCO3- exchanger, which is electroneutral, Na+ independent, and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) sensitive. Stimulation of this Cl(-)-HCO3- exchanger requires intact microtubules, suggesting that vesicular transport may be required to activate this exchanger. To determine if intracellular alkalinization stimulates biliary HCO3- excretion and bile flow in the intact liver by vesicle-mediated exocytosis, isolated perfused rat livers (IPRL) were alkalinized by two protocols. Isohydric changes in CO2 and HCO3- concentrations induced transient increases in bile flow by 36% (P < 0.01), which were abolished by DIDS (0.01 mM), inhibited by pretreatment with colchicine (P = 0.01), but not affected by membrane depolarization with the K(+)-channel blocker BaCl2 (1 mM). Similarly, perfusion with 20 mM NH4Cl produced a 42% increase in bile flow (P < 0.01) and a 26% increase in biliary HCO3- excretion. Both the increases in bile flow and HCO3- excretion were almost completely blocked by DIDS and inhibited by pretreatment with colchicine (P < 0.01). Biliary excretion of horseradish peroxidase was also increased during intracellular alkalinization with either protocol (P < 0.01). These findings suggest that intracellular alkalinization stimulates bile flow and biliary HCO3- excretion. Microtubule-dependent vesicular-mediated exocytosis is involved in this response.

scholarly journals A commercial grain-free diet does not decrease plasma amino acids and taurine status but increases bile acid excretion when fed to Labrador Retrievers

2020 ◽  
Vol 4 (3) ◽  
Author(s):  
Renan A Donadelli ◽  
Julia G Pezzali ◽  
Patricia M Oba ◽  
Kelly S Swanson ◽  
Craig Coon ◽  
...  
Keyword(s):  
Amino Acids ◽  
Bile Acid ◽  
Whole Blood ◽  
Repeated Measures ◽  
Case Reports ◽  
Fecal Excretion ◽  
Plasma Amino Acids ◽  
Acid Excretion ◽  
Bile Acid Excretion ◽  
Labrador Retrievers

Abstract Grain-free diets tend to have greater inclusions of pulses in contrast to grain-based diets. In 2018, the Food and Drug Administration (FDA) released a statement that grain-free diets may be related to the development of canine dilated cardiomyopathy (DCM). However, all dog foods met regulatory minimums for nutrient inclusion recommended by the Association of American Feed Controls Official. In some FDA case reports, but not all, dogs diagnosed with DCM also had low concentrations of plasma or whole blood taurine; thus, we hypothesized that feeding these diets will result in reduced taurine status from baseline measures. The objective of this study was to determine the effects of feeding a grain-free diet to large-breed dogs on taurine status and overall health. Eight Labrador Retrievers (four males and four females; Four Rivers Kennel, MO) were individually housed and fed a commercial complete and balanced grain-free diet (Acana Pork and Squash formula; APS) for 26 wk. Fasted blood samples were collected prior to the start of the trial (baseline; week 0) and at weeks 13 and 26 for analyses of blood chemistry, hematology, plasma amino acids, and whole blood taurine. Urine was collected by free catch at weeks 0 and 26 for taurine and creatinine analyses. Fresh fecal samples were collected at weeks 0 and 26 for bile acid analyses. Data were analyzed using the GLIMMIX procedure with repeated measures in SAS (v. 9.4). Plasma His, Met, Trp, and taurine and whole blood taurine concentrations increased over the course of the study (P &lt; 0.05). Urinary taurine to creatinine ratio was not affected by diet (P &gt; 0.05). Fecal bile acid excretion increased after 26 wk of feeding APS to dogs. Despite the higher fecal excretion of bile acids, plasma and whole blood taurine increased over the 26-wk feeding study. These data suggest that feeding APS, a grain-free diet, over a 26-wk period improved taurine status in Labrador Retrievers and is not the basis for the incidence of DCM for dogs fed APS. Other factors that may contribute to the etiology of DCM should be explored.

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