scholarly journals Diurnal variations in muscle and liver glycogen differ depending on the timing of exercise

2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Kaito Iwayama ◽  
Yoko Tanabe ◽  
Fumiya Tanji ◽  
Takahiro Ohnishi ◽  
Hideyuki Takahashi
Keyword(s):  
Energy Metabolism ◽  
Magnetic Resonance ◽  
Muscle Glycogen ◽  
Liver Glycogen ◽  
Diurnal Variations ◽  
Future Research ◽  
Resonance Spectroscopy ◽  
Molecular Sensors ◽  
Single Bout ◽  
Baseline Levels

AbstractIt has been suggested that glycogen functions not only in carbohydrate energy storage, but also as molecular sensors capable of activating lipolysis. This study aimed to compare the variation in liver and muscle glycogen during the day due to different timing of exercise. Nine healthy young men participated in two trials in which they performed a single bout of exercise at 70% of their individual maximal oxygen uptake for 60 min in the post-absorptive (morning) or post-prandial (afternoon) state. Liver and muscles glycogen levels were measured using carbon magnetic resonance spectroscopy (13C MRS). Diurnal variations in liver and muscle glycogen compared to baseline levels were significantly different depending on the timing of exercise. The effect of the timing of exercise on glycogen fluctuation is known to be related to a variety of metabolic signals, and the results of this study will be useful for future research on energy metabolism.

scholarly journals Liver and muscle glycogen repletion using 13C magnetic resonance spectroscopy following ingestion of maltodextrin, galactose, protein and amino acids

2013 ◽  
Vol 110 (5) ◽  
pp. 848-855 ◽  
Author(s):  
Eva Detko ◽  
John P. O'Hara ◽  
Peter E. Thelwall ◽  
Fiona E. Smith ◽  
Djordje G. Jakovljevic ◽  
...  
Keyword(s):  
Amino Acids ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Body Mass ◽  
Muscle Glycogen ◽  
Liver Glycogen ◽  
Resonance Spectroscopy ◽  
Post Exercise ◽  
Glycogen Repletion ◽  
Postprandial Insulin

The present study evaluated whether the inclusion of protein (PRO) and amino acids (AA) within a maltodextrin (MD) and galactose (GAL) recovery drink enhanced post-exercise liver and muscle glycogen repletion. A total of seven trained male cyclists completed two trials, separated by 7 d. Each trial involved 2 h of standardised intermittent cycling, followed by 4 h recovery. During recovery, one of two isoenergetic formulations, MD–GAL (0·9 g MD/kg body mass (BM) per h and 0·3 g GAL/kg BM per h) or MD–GAL-PRO+AA (0·5 g MD/kg BM per h, 0·3 g GAL/kg BM per h, 0·4 g whey PRO hydrolysate plus l-leucine and l-phenylalanine/kg BM per h) was ingested at every 30 min. Liver and muscle glycogen were measured after depletion exercise and at the end of recovery using 1H-13C-magnetic resonance spectroscopy. Despite higher postprandial insulin concentations for MD–GAL-PRO+AA compared with MD–GAL (61·3 (se 6·2) v. 29·6 (se 3·0) mU/l, (425·8 (se 43·1) v. 205·6 (se 20·8) pmol/l) P= 0·03), there were no significant differences in post-recovery liver (195·3 (se 2·6) v. 213·8 (se 18·0) mmol/l) or muscle glycogen concentrations (49·7 (se 4·0) v. 51·1 (se 7·9) mmol/l). The rate of muscle glycogen repletion was significantly higher for MD–GAL compared with MD–GAL-PRO+AA (5·8 (se 0·7) v. 3·7 (se 0·6) mmol/l per h, P= 0·04), while there were no significant differences in the rate of liver glycogen repletion (15·0 (se 2·5) v. 13·0 (se 2·7) mmol/l per h). PRO and AA within a MD–GAL recovery drink, compared with an isoenergetic mix of MD–GAL, did not enhance but matched liver and muscle glycogen recovery. This suggests that the increased postprandial insulinaemia only compensated for the lower MD content in the MD–GAL-PRO+AA treatment.

scholarly journals Sensory over-responsivity is related to GABAergic inhibition in thalamocortical circuits

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Emily T. Wood ◽  
Kaitlin K. Cummings ◽  
Jiwon Jung ◽  
Genevieve Patterson ◽  
Nana Okada ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Sensory Information ◽  
Network Connectivity ◽  
Sensory Stimulation ◽  
Autism Spectrum ◽  
Future Research ◽  
Resonance Spectroscopy ◽  
Gamma Aminobutyric Acid ◽  
Sensory Stimuli ◽  
Brain Responses

AbstractSensory over-responsivity (SOR), extreme sensitivity to or avoidance of sensory stimuli (e.g., scratchy fabrics, loud sounds), is a highly prevalent and impairing feature of neurodevelopmental disorders such as autism spectrum disorders (ASD), anxiety, and ADHD. Previous studies have found overactive brain responses and reduced modulation of thalamocortical connectivity in response to mildly aversive sensory stimulation in ASD. These findings suggest altered thalamic sensory gating which could be associated with an excitatory/inhibitory neurochemical imbalance, but such thalamic neurochemistry has never been examined in relation to SOR. Here we utilized magnetic resonance spectroscopy and resting-state functional magnetic resonance imaging to examine the relationship between thalamic and somatosensory cortex inhibitory (gamma-aminobutyric acid, GABA) and excitatory (glutamate) neurochemicals with the intrinsic functional connectivity of those regions in 35 ASD and 35 typically developing pediatric subjects. Although there were no diagnostic group differences in neurochemical concentrations in either region, within the ASD group, SOR severity correlated negatively with thalamic GABA (r = −0.48, p < 0.05) and positively with somatosensory glutamate (r = 0.68, p < 0.01). Further, in the ASD group, thalamic GABA concentration predicted altered connectivity with regions previously implicated in SOR. These variations in GABA and associated network connectivity in the ASD group highlight the potential role of GABA as a mechanism underlying individual differences in SOR, a major source of phenotypic heterogeneity in ASD. In ASD, abnormalities of the thalamic neurochemical balance could interfere with the thalamic role in integrating, relaying, and inhibiting attention to sensory information. These results have implications for future research and GABA-modulating pharmacologic interventions.

Contribution of net hepatic glycogenolysis to glucose production during the early postprandial period

1996 ◽  
Vol 270 (1) ◽  
pp. E186-E191 ◽  
Author(s):  
K. F. Petersen ◽  
T. Price ◽  
G. W. Cline ◽  
D. L. Rothman ◽  
G. I. Shulman
Keyword(s):  
Magnetic Resonance ◽  
Glycogen Content ◽  
Hepatic Glucose Production ◽  
Liver Volume ◽  
Glucose Production ◽  
Liver Glycogen ◽  
Whole Body ◽  
Hepatic Glycogen ◽  
Resonance Spectroscopy ◽  
13C Nuclear Magnetic Resonance

Relative contributions of net hepatic glycogenolysis and gluconeogenesis to glucose production during the first 12 h of a fast were studied in 13 healthy volunteers by noninvasively measuring hepatic glycogen content using 13C nuclear magnetic resonance spectroscopy. Rates of net hepatic glycogenolysis were calculated by multiplying the change in liver glycogen content with liver volume determined by magnetic resonance imaging. Rates of gluconeogenesis were calculated as the difference between rates of glucose production determined with an infusion of [6,6-2H]-glucose and net hepatic glycogenolysis. At 6 P.M. a liquid mixed meal (1,000 kcal; 60% as glucose) was given, to which [2-2H]glucose was added to trace glucose absorption. Hepatic glycogen content was measured between 11 P.M. and 1 A.M. and between 3 and 6 A.M. At 11 P.M. the concentration was 470 mM and it decreased linearly during the night. The mean liver volume was 1.47 +/- 0.06 liters. Net hepatic glycogenolysis (5.8 +/- 0.8 mumol.kg body wt-1.min-1) accounted for, on average, 45 +/- 6% and gluconeogenesis for 55 +/- 6% of the rate of whole body glucose production (12.6 +/- 0.6 mumol.kg body wt-1.min-1). In conclusion, this study shows that, even early in the phase of the postabsorptive period when liver glycogen stores are maximal, gluconeogenesis contributes approximately 50% to hepatic glucose production.

scholarly journals Evaluation of energy metabolism in masseter muscles of TMD patients using 31P-MRS(magnetic resonance spectroscopy).

1997 ◽  
Vol 4 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Taihiko Yamaguchi ◽  
Kaori Satoh ◽  
Kosetsu Komatsu ◽  
Tomoyoshi Kimura ◽  
Yoichi Uchiyama ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
31P Mrs ◽  
Masseter Muscles

scholarly journals P1240EVALUATION OF COGNITIVE FUNCTION IN HEMODIALYSIS PATIENTS USING MAGNETIC RESONANCE SPECTROSCOPY: FIVE YEARS FOLLOW UP RESULTS

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Shigeru Owada ◽  
Aki Hirayama ◽  
Teruhiko Maeba
Keyword(s):  
Cognitive Impairment ◽  
Cognitive Function ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Future Research ◽  
Resonance Spectroscopy ◽  
Brain Metabolites ◽  
Dialysis Patients ◽  
Cont Group ◽  
The Brain

Abstract Background and Aims In Japan, the elderly population is increasing remarkably, and dialysis patients are aging as usual. According to statistics from the Japanese Society for Dialysis Therapy, at the end of 2017, the incidence of HD patients is estimated to be 3 per 1,000 population, and by the end of 2020, the average age will be over 70 years. Therefore, early diagnosis of cognitive impairment is an important issue. With the aging of dialysis patients, the number of cases showing cognitive dysfunction increase in addition to the decline of physical strength. The problem of the onset of dementia involves many difficulties in medical treatment and nursing. Magnetic resonance spectroscopy (MRS) has been progressing from 1970s to evaluate neurological functions by measuring metabolites in the brain non-invasively. There are few reports using MRS for dialysis patients. In this study, we investigated the brain metabolites of hemodialysis (HD) patients with or without cognitive impairments using MRS and evaluated its usefulness for the diagnosis of cognitive disorder. Method A Toshiba MR device of 1.5 T was used. PRESS sequence was used to acquire water-suppressed 1H-MRS. Timing was TR/TE 2000/25 ms. Three kinds of brain metabolites, namely N-acethylaspartate (NAA), creatine (Cr) and mioinositol (MI) in the posterior cingulate gyrus were measured for 25 healthy adults (Cont group, 44±16 y.o.) and 84 HD patients (HD group, 74±11 y.o.), and ratios of NAA/Cr, MI/Cr and MI/NAA were calculated. The concentration of each metabolite was analyzed using LC model. HD patients were classified into three groups, namely normal cognitive function group (HD-N, n=25, 72±16 y.o.), mild cognitive impairment (HD-M, n=29, 74±9 y.o.) and dementia (HD-D, n=30, 79±8 y.) using MMSE test. Also, sequential changes of the brain metabolites were evaluated for 13 patients with worse cognitive function prospectively. Results HD patients showed a significant decrease of NAA and increases of MI and MI/NAA ratios compared to those of Cont group, suggesting that some metabolic abnormalities were inducted in HD. With a detailed classification of cognitive function in HD patients, NAA/Cr ratios were 1.69±0.17, 1.57±0.15, 1.71±0.20 and 1.54±0.22 in Cont, HD-N, HD-M and HD-D groups, respectively, and was significantly lower even in HD-N group than that of Cont group. MI/Cr ratios were 0.78±0.21, 0.90±0.21, 0.95±0.28 and 1.02±0.27 in Cont, HD-N, HD-M and HD-D groups, respectively, and those of HD-N/-M/-D were significantly higher than that of Cont group. Also, the value of HD-D was significantly higher than those in the other groups. MI/NAA ratios were 0.46±0.13, 0.56±0.17, 0.54±0.16 and 0.66±0.15, in Cont, HD-N, HD-M and HD-D groups, respectively. Again, those of HD-N/-M/-D were significantly higher than that of Cont group. HD-D group was highest among the HD patients. In the prospective study, dementia progressed in 10 of 13 HD patients who were observed more than 5 years. The MI/NAA ratio increased in the patients with dementia progression (from 0.58±0.11 to 1.24±0.17) while that value of the patients without dementia progression showed no changes (from 0.51±0.14 to 0.55±0.18). Conclusion These result suggest that the measurement of metabolic fluctuation in the brain using MRS is useful for the diagnosis of cognitive function in HD patients. The MI/NAA value is a strong candidate for a predictive biomarker of dementia progression. In the future, research and development of measurements of various parts of the brain and their integration to show changes in the whole brain are desired.

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