Central and peripheral sympathetic characteristics in hypertension considered from differences of catecholamine metabolite concentrations in plasma before and after adrenalectomy in male 2-month-old SHRSP and WKY

1992 ◽  
Vol 54 (2) ◽  
pp. 175-181 ◽  
Author(s):  
J. A. Woolliams ◽  
R. S. Nisbet ◽  
P. Løvendahl

AbstractEighty calves of both sexes, 4 months of age, of two lines, differing in genetic merit for fat plus protein production by 70 kg per 305-day lactation, were given one of four diets differing in protein content to give an estimated range of protein intakes from 299 to 530 g/day. After 21 days the calves were fasted for 72 h. Samples of blood were taken before and after feeding in the morning and afternoon prior to fasting, seven further samples were taken throughout the fast and five samples were taken ranging from 0·5 to 7·5 h after food was re-introduced. The samples were analysed for concentrations of urea, free fatty acids (FFA), glucose, triglyceride and f5-hydroxybutyrate.No association between metabolite concentrations and predicted breeding value (PBV) were found at any stage of the trial except for the effect of feeding on FFA concentration, the rate of increase of FFA during the fast and its ultimate concentration. These associations with FFA depended on the sex of the calf and were either absent or less marked in males. The results strengthen the possibility that FFA concentrations during fasting are related to PBV in females, and that sexual dimorphism may explain differing conclusions amongst previous trials.The magnitude of the estimate of coheritability of urea concentration during fasting with PBV, pooled across experiments, is reduced from -0·193 to -0·066 (s.e. 0·037) by inclusion of these results. However, heterogeneity between experiments is evident and remains to be explained. This suggests that urea concentrations are not consistent predictors of genetic merit and cannot be considered to be reliable for use in practice.


1988 ◽  
Vol 65 (2) ◽  
pp. 878-887 ◽  
Author(s):  
C. A. Piantadosi ◽  
P. A. Lee ◽  
A. L. Sylvia

Cerebrocortical b-cytochromes have been found to be sensitive to reduction in the presence of CO and O2 in vivo. CO-mediated cytochrome b reduction responses in "bloodless" rats were correlated in this study with changes in concentrations of high energy and glycolytic intermediates measured in cortex after rapid brain freezing. Cytochrome redox state and metabolite concentrations also were compared with cerebral blood flow (CBF) and cerebral metabolic rate for O2 (CMRo2) measured before and after CO administration. No definite biochemical evidence of energy limitation was found in parietal cortex after the fluorocarbon-for-blood exchange; however, CO had direct effects on brain metabolite concentrations. Fifteen-minute CO exposures at inspired CO/O2 of 0.003-0.06 increased cerebrocortical phosphocreatine and ADP and decreased creatine concentration. CO exposure produced no significant changes in either ATP concentration or CMRo2, although CBF increased slightly. These findings may be interpreted to indicate that CO binding to cytochrome aa3 at low CO/O2 in vivo increases extramitochondrial pH relative to that within the mitochondrial matrix. In the process, cytochrome b reduction levels increase, possibly signaling an increased efficiency of oxidative phosphorylation relative to O2 uptake by unblocked respiratory chains.


Toxics ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 53
Author(s):  
Manori J. Silva ◽  
Lee-Yang Wong ◽  
James L. Preau ◽  
Ella Samandar ◽  
Emmanuela Obi ◽  
...  

We know little about the potential health risks from exposure to diisoheptyl phthalate (DiHpP), a plasticizer used in commercial applications. The production of DiHpP ended in the United States in 2010, but DiHpP may still be present in phthalate diester mixtures. To investigate human exposure to DiHpP, we used three oxidative metabolites of DiHpP: Monohydroxyheptyl phthalate (MHHpP), mono-oxoheptylphthalate (MOHpP), and monocarboxyhexyl phthalate (MCHxP) as exposure biomarkers. We analyzed urine collected anonymously in 2000 (N = 144) and 2018–2019 (N = 205) from convenience groups of U.S. adults using high-performance liquid chromatography coupled with isotope-dilution high-resolution mass spectrometry. We detected MCHxP in all the samples tested in 2000 (GM = 2.01 ng/mL) and 2018–2019 (GM = 1.31 ng/mL). MHHpP was also detected in 100% of the 2018–2019 samples (GM = 0.59 ng/mL) and 96% of the 2000 urine samples analyzed (GM = 0.38 ng/mL). MOHpP was detected in 57% (2018–2019, GM = 0.03 ng/mL) and 92% (2000, GM = 0.19 ng/mL) of samples. The presence of MHHpP, MOHpP, and MCHxP in the 2018–2019 samples suggests recent exposure to DiHpP. Intercorrelations between metabolite concentrations were more significant in samples collected in 2000 than in samples collected in 2018–2019. The differences in urinary metabolite profiles and intercorrelations from samples collected during 2000 and 2018–2019 likely reflects changes in the composition of commercial DiHpP formulations before and after 2010.


1992 ◽  
Vol 55 (2) ◽  
pp. 295-298 ◽  
Author(s):  
S. E. Bachman ◽  
M. L. Galyean ◽  
D. M. Hallford ◽  
C. E. Heird ◽  
G. C. Duff

Eight wether lambs were used to determine effects of an oestradiol-17β (E2β) implant on metabolic responses to an epinephrine challenge. Blood was sampled before and after an epinephrine challenge, on days 0 and 22 of E2p implantation.Oestradiol-17 ft implants increased pre-injection (basal) serum insulin (INS), growth hormone and free fatty acids (FFA), and decreased basal serum urea nitrogen. After 21 days of E2Pimplantation, total concentrations of FFA decreased and INS increased in response to the epinephrine challenge compared with pre-implantation values. It is concluded that E2/3 implants alter metabolic responses to an epinephrine challenge in wether lambs.


1975 ◽  
Vol 21 (6) ◽  
pp. 735-740 ◽  
Author(s):  
Teruo Kitagawa ◽  
Barbara A Smith ◽  
Eleanor S Brown

Abstract Phenylalanine and its metabolites were determined in serum and urine of phenylketonuric subjects and in subjects with milder hyperphenylalaninemia in whom blood phenylalanine concentrations were usually <200 mg/liter. Metabolite concentrations were related to serum phenylalanine, and in hyperphenylalaninemic subjects were between those for treated and untreated phenylketonuric subjects. Phenyllactic and phenylpyruvic acids were excreted by all of the mild hyperphenylalaninemic subjects except for the youngest (one-year-old twins) and the only subject with a serum phenylalanine of <100 mg/liter. Serum and urinary metabolites of heterozygotes of both conditions were similar before and after a phenylalanine load. The similar pattern of metabolites in phenylketonuric and mild hyperphenylalaninemic subjects reinforces the belief that the latter have some phenylalanine hydroxylase activity, and that this is the essential difference between the two groups.


2015 ◽  
Vol 93 (12) ◽  
pp. 5791-5800 ◽  
Author(s):  
J. T. Cribbs ◽  
B. C. Bernhard ◽  
T. R. Young ◽  
M. A. Jennings ◽  
N. C. Burdick Sanchez ◽  
...  

Author(s):  
David L. Ashley ◽  
Víctor R. De Jesús ◽  
Osama A. Abulseoud ◽  
Marilyn A. Huestis ◽  
Daniel F. Milan ◽  
...  

Cannabis use through smoking, vaping, or ingestion is increasing, but only limited studies have investigated the resulting exposure to harmful chemicals. N-acetyl-S-(2-cyanoethyl)-L-cysteine (2CYEMA), a urinary metabolite of acrylonitrile, a possible carcinogen, is elevated in the urine of past-30-day cannabis users compared to non-cannabis users. Five frequent and five occasional cannabis users smoked and vaped cannabis on separate days; one also consumed cannabis orally. Urine samples were collected before and up to 72 h post dose and urinary 2CYEMA was quantified. We compared 2CYEMA pre-exposure levels, maximum concentration, time at maximum concentration for occasional versus frequent users following different exposure routes, and measured half-life of elimination. Smoking cannabis joints rapidly (within 10 min) increased 2CYEMA in the urine of occasional cannabis users, but not in frequent users. Urine 2CYEMA did not consistently increase following vaping or ingestion in either study group. Cigarette smokers had high pre-exposure concentrations of 2CYEMA. Following cannabis smoking, the half-lives of 2CYEMA ranged from 2.5 to 9.0 h. 2CYEMA is an effective biomarker of cannabis smoke exposure, including smoke from a single cannabis joint, however, not from vaping or when consumed orally. When using 2CYEMA to evaluate exposure in cannabis users, investigators should collect the details about tobacco smoking, route of consumption, and time since last use as possible covariates.


Metabolites ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 141 ◽  
Author(s):  
Erica Pitti ◽  
Greta Petrella ◽  
Sara Di Marino ◽  
Vincenzo Summa ◽  
Marco Perrone ◽  
...  

Saliva samples of seventeen soccer players were analyzed by nuclear magnetic resonance before and after an official match. Two different ways of normalizing data are discussed, using total proteins and total metabolite concentrations. Changes in markers related to energy, hydration status, amino acids and other compounds were found. The limits and advantages of using saliva to define the systemic responses to exercise are examined, both in terms of data normalization and interpretation, and the time that the effect lasts in this biofluid, which is shorter to that commonly observed in blood. The heterogeneous nature and different timing of the exercise developed by players also plays an important role in the metabolic changes that can be measured. Our work focuses mainly on three different aspects: The effect that time sampling has on the observed effect, the type of normalization that is necessary to perform in order to cope with changes in water content, and the metabolic response that can be observed using saliva.


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