Cysteine—Homocysteine Mixed Disulphide: Differing Plasma Concentrations in Normal Men and Women

1979 ◽  
Vol 57 (2) ◽  
pp. 211-215 ◽  
Author(s):  
D. E. L. Wilcken ◽  
V. J. Gupta
Keyword(s):  
Plasma Concentrations ◽  
Premenopausal Women ◽  
Mean Value ◽  
Methionine Metabolism ◽  
Men And Women ◽  
Mean Values ◽  
Branched Chain Amino Acid ◽  
Branched Chain ◽  
Normal Men ◽  
Amino Acid Concentrations

1. The mixed disulphide of cysteine and homocysteine is known always to be present in the plasma of patients with homocystinuria, an abnormality of methionine metabolism. Recently we have shown that it is also detectable in low concentration in the plasma of normal fasting man. In the present study we measured mixed disulphide concentrations after an overnight fast in 24 normal men and compared the findings with those obtained in 24 normal premenopausal women of similar age. 2. The mean value for men (± sd) of 3·3 ± 0·8 μmol/l was significantly higher than that for women (2·4 ± 0·7 μmol/l; P < 0·001). Of the other neutral and acidic amino acids measured mean values for leucine, isoleucine and valine (P < 0·001) and cystine (P < 0·01) were also higher in the men but methionine concentrations were not significantly different. 3. The higher branched-chain amino acid concentrations in men could be related to larger muscle bulk and protein intake, but the higher cysteine—homocysteine mixed disulphide concentrations are consistent with differences in methionine metabolism between men and women under the age of 50 years.

Hyperglycemia after protein ingestion concurrent with injection of a GLP-1 receptor agonist in rats: a possible role for dietary peptides

2005 ◽  
Vol 289 (3) ◽  
pp. R688-R694 ◽  
Author(s):  
Alfred Aziz ◽  
G. Harvey Anderson ◽  
Adria Giacca ◽  
France Cho
Keyword(s):  
Amino Acid ◽  
Receptor Agonist ◽  
Plasma Concentrations ◽  
Intact Proteins ◽  
Branched Chain Amino Acid ◽  
Protein Ingestion ◽  
Amino Acid Mixtures ◽  
Glucagon Like Peptide 1 ◽  
Branched Chain ◽  
Amino Acid Concentrations

Protein ingestion after injection of the glucagon-like peptide-1 receptor agonist Exendin-4 (Ex-4) causes hyperglycemia in rats. The objectives of this study were to determine the components of protein digestion responsible for this effect and to associate it with changes in the concentrations of other metabolites and hormones. Two experiments were conducted. In the first experiment, food-deprived rats were gavaged with intact whey (WP) or albumin protein, their hydrolysates, amino acid mixtures (1 g/2.5 ml), or water 5 min after injection of either PBS or Ex-4 (0.5 μg/rat). Tail vein blood was analyzed for glucose over 2 h. In the second experiment, food-deprived rats were gavaged with WP with or without Ex-4. Groups of conscious rats were killed by decapitation either before, or at selected times after gavage. Plasma concentrations of glucose, amino acids, free fatty acids (FFA), glycerol, insulin, glucagon, and leptin were measured. In experiment 1, blood glucose was higher when intact proteins and protein hydrolysates, but not amino acid mixtures, were given with than without Ex-4 ( P < 0.05). In experiment 2, concentrations of glucose, FFA, and the ratio of tyrosine to branched-chain amino acid were higher ( P < 0.01), but leptin and essential amino acid concentrations were lower ( P < 0.05), and insulin, glucagon, and glycerol were similar when WP was given with or without Ex-4. We conclude that the hyperglycemia caused by the administration of Ex-4 concurrently with dietary protein arises from the action of peptides released during digestion and their interaction with Ex-4 in the regulation of glucose, fatty acid, and amino acid metabolism.

Comparison of effects of sustained isocapnic hypoxia on ventilation in men and women

1997 ◽  
Vol 83 (2) ◽  
pp. 599-607 ◽  
Author(s):  
Dimitar Sajkov ◽  
Alister Neill ◽  
Nicholas A. Saunders ◽  
R. Douglas McEvoy
Keyword(s):  
Menstrual Cycle ◽  
Minute Ventilation ◽  
Premenopausal Women ◽  
Follicular Phase ◽  
Inspiratory Time ◽  
Men And Women ◽  
Ventilatory Responses ◽  
Reduced Frequency ◽  
Normal Men ◽  
Respiratory Depressant

Sajkov, Dimitar, Alister Neill, Nicholas A. Saunders, and R. Douglas McEvoy. Comparison of the effects of sustained isocapnic hypoxia on ventilation in men and women. J. Appl. Physiol. 83(2): 599–607, 1997.—Sleep-related respiratory disturbances are more common in men than in premenopausal women. This might, in part, be due to different susceptibilities to the respiratory depressant effects of hypoxia. Therefore, we compared ventilation during 10 min of baseline room-air breathing and 20-min sustained isocapnic hypoxia (fractional inspired O2 = 11%, arterial saturation of O2 ≈ 80%) followed by 10 min of breathing 100% O2 in 10 normal men and in 10 women in the follicular phase of the menstrual cycle. Control measurements were made during two transitions from room air (10 min) to 100% O2 (10 min) and averaged. Inspired minute ventilation (V˙i) after 2 min of hypoxia was the same in men and women [131 ± 6.1% baseline for men, 136 ± 7.7% baseline for women; not significant (NS)] and declined to the same level after 20 min (115 ± 5.0% baseline for men, 116 ± 6.6% baseline for women; NS) associated with a similar decline in inspiratory time and tidal volume. Breathing frequency did not change.V˙i decreased transiently during subsequent 100% O2 breathing in both men and women, associated with reduced frequency and duty cycle and increased expiratory time. The fall inV˙i was significantly greater than that observed during control hyperoxia experiments in men but not in women. We conclude that ventilatory responses to sustained isocapnic hypoxia do not differ between awake healthy men and women in the follicular phase of their menstrual cycle. However, after termination of isocapnic hypoxia, men appear to depress their ventilation to a greater degree than women.

scholarly journals Branched-Chain Amino Acid Oxidation Is Elevated in Adults with Morbid Obesity and Decreases Significantly after Sleeve Gastrectomy

2020 ◽  
Vol 150 (12) ◽  
pp. 3180-3189
Author(s):  
Hong Chang Tan ◽  
Jean W Hsu ◽  
Jean-Paul Kovalik ◽  
Alvin Eng ◽  
Weng Hoong Chan ◽  
...  
Keyword(s):  
Morbid Obesity ◽  
Sleeve Gastrectomy ◽  
Plasma Concentrations ◽  
Fat Free Mass ◽  
Acid Oxidation ◽  
Morbidly Obese ◽  
Healthy Weight ◽  
Leucine Oxidation ◽  
Branched Chain Amino Acid ◽  
Branched Chain

ABSTRACT Background Plasma concentrations of branched-chain amino acids (BCAAs) are elevated in obese individuals with insulin resistance (IR) and decrease after bariatric surgery. However, the metabolic mechanisms are unclear. Objectives Our objectives are to compare leucine kinetics between morbidly obese and healthy-weight individuals cross-sectionally, and to prospectively evaluate changes in the morbidly obese after sleeve gastrectomy. We hypothesized that leucine oxidation is slower in obese individuals and increases after surgery. Methods Ten morbidly obese [BMI (in kg/m2) ≥32.5, age 21–50 y] and 10 healthy-weight participants (BMI &lt;25), matched for age (median ∼30 y) but not gender, were infused with [U-13C6] leucine and [2H5] glycerol to quantify leucine and glycerol kinetics. Morbidly obese participants were studied again 6 mo postsurgery. Primary outcomes were kinetic parameters related to BCAA metabolism. Data were analyzed by nonparametric methods and presented as median (IQR). Results Participants with obesity had IR with an HOMA-IR (4.89; 4.36–8.76) greater than that of healthy-weight participants (1.32; 0.99–1.49; P &lt; 0.001) and had significantly faster leucine flux [218; 196–259 compared with 145; 138–149 μmol · kg fat-free mass (FFM)−1 · h−1], oxidation (24.0; 17.9–29.8 compared with 16.1; 14.3–18.5 μmol · kg FFM−1 · h−1), and nonoxidative disposal (204; 190–247 compared with 138; 129–140 μmol · kg FFM−1 · h−1) (P &lt; 0.017 for all). After surgery, the morbidly obese had a marked improvement in IR (3.54; 3.06–6.08; P = 0.008) and significant reductions in BCAA concentrations (113; 95–157 μmol/L) and leucine oxidation (9.37; 6.85–15.2 μmol · kg FFM−1 · h−1) (P = 0.017 for both). Further, leucine flux in this group correlated significantly with IR (r = 0.78, P &lt; 0.001). Conclusions BCAA oxidation is not impaired but elevated in individuals with morbid obesity. Plasma BCAA concentrations are lowered after surgery owing to slower breakdown of body proteins as insulin's ability to suppress proteolysis is restored. These findings suggest that IR is the underlying cause and not the consequence of elevated BCAAs in obesity.

Prolonged submaximal eccentric exercise is associated with increased levels of plasma IL-6

1997 ◽  
Vol 273 (1) ◽  
pp. E85-E91 ◽  
Author(s):  
T. Rohde ◽  
D. A. MacLean ◽  
E. A. Richter ◽  
B. Kiens ◽  
B. K. Pedersen
Keyword(s):  
Eccentric Exercise ◽  
Proliferative Response ◽  
Muscle Protein ◽  
Plasma Concentrations ◽  
Cytokine Response ◽  
Cytotoxic Activities ◽  
Branched Chain Amino Acid ◽  
Muscle Protein Degradation ◽  
Branched Chain ◽  
The Relationship

To study the relationship between exercise-related muscle proteolysis and the cytokine response, a prolonged eccentric exercise model of one leg was used. Subjects performed two trials [a branched-chain amino acid (BCAA) supplementation and a control trial]. The release of amino acids from muscle during and after the eccentric exercise was decreased in the BCAA trial, suggesting a suppression of net muscle protein degradation. The plasma concentrations of interleukin (IL)-6 increased from 0.75 +/- 0.19 (preexercise) to 5.02 +/- 0.96 pg/ml (2 h postexercise) in the control trial and in the BCAA supplementation trial from 1.07 +/- 0.41 to 4.15 +/- 1.21 pg/ml. Eccentric exercise had no effect on the concentrations of neutrophils, lymphocytes, CD16+/CD56+, CD4+, CD8+, CD14+/CD38+, lymphocyte proliferative response, or cytotoxic activities. BCAA supplementation reduced the concentration of CD14+/CD38+ cells. This study shows that the concentration of IL-6 in plasma is increased after prolonged eccentric exercise and suggests that the cytokine response is independent of the muscle proteolysis that occur during exercise.

DETERMINATION OF DEHYDROEPIANDROSTERONE AND DEHYDROEPIANDROSTERONE SULPHATE IN HUMAN PLASMA USING ELECTRON CAPTURE DETECTION OF 4-ANDROSTENE-3,6,17-TRIONE AFTER GAS-LIQUID CHROMATOGRAPHY

1972 ◽  
Vol 53 (3) ◽  
pp. 461-474 ◽  
Author(s):  
F. H. de JONG ◽  
H. J. van der MOLEN
Keyword(s):  
Liquid Chromatography ◽  
Electron Capture ◽  
Plasma Concentrations ◽  
Mean Value ◽  
Electron Capture Detection ◽  
Gas Liquid Chromatography ◽  
Mean Values ◽  
Peripheral Plasma ◽  
Competitive Protein Binding ◽  
The Mean

SUMMARY A method for the measurement of dehydroepiandrosterone (DHA) and of its sulphate (DHAS) in human peripheral plasma is described and evaluated. After isolation of DHA from the sample the steroid is oxidized to 4-androstene-3,6,17-trione, which is measured with an electron capture detector after gas—liquid chromatography. It is possible to detect 100 pg 4-androstene-3,6,17-trione. The smallest amount of DHA per sample that can be distinguished from zero is approximately 4 ng, when recovery (27·9 ± 8·8%) and method blank (0·23 ± 0·38 ng) are taken into account. The oxidation to 4-ene-3,6-diones is specific for steroidal 5-en-3-ols. Specificity for DHA is ensured by several chromatographic steps. Repeated estimation of 10 ng DHA gave a mean value of 9·6 ± 1·45 (s.d.) ng (n = 35). Mean concentrations and their standard deviations for DHA and DHAS in peripheral plasma from 18 individuals were 0·50 ± 0·25 and 78 ± 40 μg/100 ml, respectively, at 08.30 h and 0·32 ± 0·17 and 84 ± 34 μg/100 ml, respectively, at 17.00 h of the same day. Levels of plasma cortisol in the same plasma samples estimated with a competitive protein-binding method were 16·7 ± 1·8 and 11·9 ± 3·8 μg/100 ml, respectively. No significant differences between the sexes were observed by any of the three assays. The mean values of the plasma concentrations of cortisol and DHA in the morning were significantly higher than those in the evening (P < 0·001 and P < 0·005, respectively). In contrast, the mean value of the plasma levels of DHAS in the morning was significantly lower than that in the evening (P < 0·025).

Serotonergic markers and lowered plasma branched-chain-amino acid concentrations in fibromyalgia

2000 ◽  
Vol 97 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Michael Maes ◽  
Robert Verkerk ◽  
Laure Delmeire ◽  
Ann Van Gastel ◽  
Fran van Hunsel ◽  
...  
Keyword(s):  
Amino Acid ◽  
Branched Chain Amino Acid ◽  
Branched Chain ◽  
Amino Acid Concentrations
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