Exchange of Metabolites in the Leg of Exercising Juvenile Diabetic Subjects

1978 ◽  
Vol 55 (1) ◽  
pp. 73-80 ◽  
Author(s):  
J. Lyngsøe ◽  
J. P. Clausen ◽  
J. Trap-Jensen ◽  
L. Sestoft ◽  
O. Schaffalitzky de Muckadell ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Glucose Uptake ◽  
Ketone Bodies ◽  
Normal Subjects ◽  
Close Correlation ◽  
Juvenile Diabetes ◽  
Control Subjects ◽  
Arterial Blood ◽  
Esterified Fatty Acids ◽  
And Control

1. Exchange of metabolic substrates was studied across the leg at rest and during a bicycle exercise demanding 50% of the maximal oxygen uptake in seven patients with juvenile diabetes and six control subjects. The leg blood flow and the femoral arterial and venous substrate concentrations were measured in the fasting state and, in the diabetic subjects, 24 h after the last administration of insulin. 2. At rest a close correlation was seen in the control subjects between the leg glucose uptake and the arterial insulin concentration. The diabetic subjects, including three patients in whom it could be shown that the insulin concentrations were extremely low, had a resting glucose uptake in the same order of magnitude as the control subjects. The glucose uptake was inversely related to the arterial concentrations of non-esterified fatty acids in both groups. 3. During exercise the glucose uptake increased in both patients and control subjects, but the increase was not related to arterial concentrations of insulin or non-esterified fatty acids. 4. The release of lactate, pyruvate, alanine and glycerol from the leg was not different in diabetic and control subjects neither at rest nor during exercise. 5. The ketonaemia was increased in the diabetic subjects, but the uptake of total ketone bodies was not different in the two groups. No increase in the uptake of total ketone bodies in control and diabetic subjects was found during exercise. The leg uptake of acetoacetate was a function of the substrate load and tended to be higher in diabetic subjects during exercise, when no net uptake of β-hydroxybutyrate was found. 6. The above results suggest that the glucose uptake in human skeletal muscle at rest depends on the concentration of insulin and possibly also of non-esterified fatty acids in arterial blood. In contrast the glucose uptake during exercise is not related to the concentration of insulin or non-esterified fatty acids, which may explain why no differences in this aspect are seen between the leg metabolism of diabetic and normal subjects.

Relationship between Serum Tryptophan and Tryptophan Metabolite Levels after Tryptophan Ingestion in Normal Subjects and Age-Related Cataract Patients

1995 ◽  
Vol 89 (6) ◽  
pp. 591-599 ◽  
Author(s):  
Roger J. W. Truscott ◽  
Anthony J. Elderfield
Keyword(s):  
Anthranilic Acid ◽  
Kynurenic Acid ◽  
Normal Subjects ◽  
Serum Levels ◽  
Xanthurenic Acid ◽  
Control Subjects ◽  
Age Related ◽  
Hydroxyanthranilic Acid ◽  
And Control ◽  
Cataract Patients

1. Cataract is the single major cause of blindness worldwide; however, the reasons for the development of this condition remain unknown. It has been suggested that the essential amino acid tryptophan may be implicated in the aetiology but definitive evidence has been lacking. 2. The serum levels of tryptophan and seven of its metabolites have been measured in both cataract patients and control subjects, after administration of tryptophan, in order to determine the typical response profile and to discover whether differences could be found in tryptophan metabolism in the two groups. 3. Tryptophan, kynurenine, kynurenic acid, xanthurenic acid, 3-hydroxyanthranilic acid, 5-hydroxyanthranilic acid, 5-hydroxytryptophan and anthranilic acid were measured by HPLC with dual electrochemical and programmable wavelength fluorescence detection. Fasting cataract patients (n = 42) and control subjects (n = 37) were given an oral dose of l-tryptophan and sera were sampled at 0, 1, 2, 4 and 6 h. 4. Statistically significant differences in the distribution of data between the two groups were observed. The responses of kynurenine and 5-hydroxyanthranilic acid were higher in cataract patients, but those of kynurenic acid and total tryptophan were lower than in control subjects. No statistically significant differences in free tryptophan, anthranilic acid, 3-hydroxyanthranilic acid, xanthurenic acid or 5-hydroxytryptophan levels were noted. 5. We conclude that there is a major subgroup of age-related cataract patients with a dysfunction in the metabolism of tryptophan. This may be related to the onset of cataract. The mechanism remains to be established but may operate via the action of tryptophan metabolites, such as 5-hydroxyanthranilic acid, which become reactive towards protein upon oxidation.

Occlusal Force and Condylar Motion in Patients with Anterior Open Bite

2005 ◽  
Vol 84 (2) ◽  
pp. 133-137 ◽  
Author(s):  
S. Miyawaki ◽  
Y. Araki ◽  
Y. Tanimoto ◽  
A. Katayama ◽  
A. Fujii ◽  
...  
Keyword(s):  
Temporomandibular Disorders ◽  
Hypothesis Test ◽  
Test Group ◽  
Normal Subjects ◽  
Open Bite ◽  
Control Groups ◽  
Anterior Open Bite ◽  
Occlusal Force ◽  
Control Subjects ◽  
And Control

Patients with open bite often show a weak occlusal force and temporomandibular disorders (TMDs). If these are the main cause of open bite, it may be hypothesized that both pre-pubertal and adult open-bite patients would show a weak occlusal force and abnormal condylar motion. The purpose of this study was to test this hypothesis. Test group subjects consisted of 13 consecutive pre-pubertal and 13 adult patients with anterior open bite. They were compared with age-matched normal subjects. The adult open-bite group showed a weaker occlusal force and a shorter range of condylar motion compared with the control subjects. In the pre-pubertal subjects, however, there were no significant differences in the occlusal force and range of condylar motion between the open-bite and control groups. Therefore, these results suggest that a weak occlusal force or TMDs may not be the main cause of open bite.

Central sympathetic outflow to skeletal muscle: the major link between non-esterified fatty acids and elevated blood pressure?

2009 ◽  
Vol 118 (1) ◽  
pp. 43-45 ◽  
Author(s):  
Markus Schlaich
Keyword(s):  
Blood Pressure ◽  
Fatty Acids ◽  
Pressor Response ◽  
The Metabolic Syndrome ◽  
Arterial Blood ◽  
Esterified Fatty Acids ◽  
System Activation ◽  
Central Sympathetic Outflow ◽  
Sympathetic Nervous System Activation

Sympathetic nervous system activation is a hallmark of several conditions associated with an adverse prognosis, including hypertension and the metabolic syndrome. Proposed mediators of increased sympathetic drive include hyperinsulinaemia, leptin, NEFAs (non-esterified fatty acids), pro-inflammatory cytokines, baroreflex impairment and others. The role of NEFAs appears to be of particular importance given the increased levels observed in human obesity and the experimental results linking the NEFA-induced pressor response to sympathetic activation. Findings from human studies have yielded conflicting results with regards to a sympathetically mediated association between NEFAs and elevated arterial blood pressure. In the present issue of Clinical Science, Florian and Pawelczyk present some interesting results obtained from a small number of healthy normotensive lean volunteers who were exposed to NEFA infusion and cardiovascular and sympathetic monitoring using state of the art methodology that appears to be in support of such a link. However, several methodological and conceptual considerations need to be taken into account when interpreting the results from this study. Put into perspective, the case for a substantial sympathetically mediated pressor response to NEFA infusion does not appear to be a very strong one.

Altered autonomic cardiac regulation in individuals with Down syndrome

2005 ◽  
Vol 289 (6) ◽  
pp. H2387-H2391 ◽  
Author(s):  
Ferdinando Iellamo ◽  
Alberto Galante ◽  
Jacopo M. Legramante ◽  
Maria Enrichetta Lippi ◽  
Claudia Condoluci ◽  
...  
Keyword(s):  
Congenital Heart Disease ◽  
Down Syndrome ◽  
Heart Disease ◽  
Congenital Heart ◽  
Sinus Node ◽  
Control Subjects ◽  
Arterial Blood ◽  
Cardiac Regulation ◽  
Autonomic Cardiac Regulation ◽  
And Control

We tested the hypothesis that individuals with Down syndrome, but without congenital heart disease, exhibit altered autonomic cardiac regulation. Ten subjects with Down syndrome (DS) and ten gender-and age-matched healthy control subjects were studied at rest and during active orthostatism, which induces reciprocal changes in sympathetic and parasympathetic traffic to the heart. Autoregressive power spectral analysis was used to investigate R-R interval variability. Baroreflex modulation of sinus node was assessed by the spontaneous baroreflex sequences method. No significant differences between DS and control subjects were observed in arterial blood pressure at rest or in response to standing. Also, R-R interval did not differ at rest. R-R interval decreased significantly less during standing in DS vs. control subjects. Low-frequency (LFNU) and high-frequency (HFNU) (both expressed in normalized units) components of R-R interval variability did not differ between DS and control subjects at rest. During standing, significant increase in LFNU and decrease in HFNU were observed in control subjects but not in DS subjects. Baroreflex sensitivity (BRS) did not differ between DS and control subjects at rest and underwent significant decrease on going from supine to upright in both groups. However, BRS was greater in DS vs. control subjects during standing. These data indicate that subjects with DS exhibit reduced HR response to orthostatic stress associated with blunted sympathetic activation and vagal withdrawal and with a lesser reduction in BRS in response to active orthostatism. These findings suggest overall impairment in autonomic cardiac regulation in DS and may help to explain the chronotropic incompetence typically reported during exercise in subjects with DS without congenital heart disease.

scholarly journals The metabolism of circulating non-esterified fatty acids by the whole animal, hind-limb muscle and uterus of pregnant ewes

1983 ◽  
Vol 49 (1) ◽  
pp. 129-143 ◽  
Author(s):  
D. W. Pethick ◽  
D. B. Lindsay ◽  
P. J. Barker ◽  
A. J. Northrop
Keyword(s):  
Fatty Acids ◽  
Hind Limb ◽  
Ketone Bodies ◽  
Gravid Uterus ◽  
Limb Muscle ◽  
Entry Rate ◽  
Esterified Fatty Acids ◽  
Arterial Concentration ◽  
Pregnant Sheep ◽  
Hind Limb Muscle

1. The over-all and regional metabolism of non-esterified fatty acids (NEFA) was studied using a combination of isotopic and arteriovenous-difference techniques.2. There was a common linear relationship, whether stearic, palmitic or oleic acids were used as tracer, between the arterial NEFA concentration and the rates of entry and oxidation.3. Assuming that the tracer used reflected the metabolism of all the NEFA, the total entry rate in fed and fasted pregnant ewes was (mean±SE) 0·44±0·02 and 0·55±0·07 mmol/h per kg body-weight respectively. Oxidation of NEFA contributed (mean±SE) 34±5 and 58±7% to the respiratory carbon dioxide in fed and fasted animals, this accounting for (mean±SE) 46±6 and 59±3% of the respective entry rates.4. Hind-limb muscle both utilized and produced NEFA. The mean gross fractional extraction (calculated from isotopic uptake) was (mean±SE) 9±1%. Gross utilization of any NEFA and appearance of 14CO2 across the muscle were linearly related to the arterial concentration of tracer fatty acid, irrespective of whether this was oleate or stearate. The amount of 14CO2 appearing was consistent with (mean±SE) 54±8% of the CO2 produced by the hind-limb being derived from NEFA oxidation.5. Infused NEFA were partly converted to ketone bodies. Uptake and oxidation in the hind-limb of ketones formed in the liver could account for approximately 20% of the 14CO2 apparently produced in muscle from NEFA. Correction for this reduces the proportion of CO2 derived from NEFA to 43%. There was some indication that ketones were also produced from NEFA in the hind-limb.6. NEFA were not a significant energy source for the gravid uterus.7. An over-all view of energy sources for the whole animal and for hind-limb muscle in normal and fasted pregnant sheep was presented.

Airway and Metabolic Responsiveness to Intravenous Salbutamol in Asthma: Effect of Regular Inhaled Salbutamol

1981 ◽  
Vol 60 (5) ◽  
pp. 579-585 ◽  
Author(s):  
J. E. Harvey ◽  
C. J. Baldwin ◽  
P. J. Wood ◽  
K. G. M. M. Alberti ◽  
A. E. Tattersfield
Keyword(s):  
Fatty Acids ◽  
Cyclic Nucleotide ◽  
Response Curve ◽  
Normal Subjects ◽  
Asthmatic Patients ◽  
Esterified Fatty Acids ◽  
Show Evidence ◽  
Airway Response ◽  
Adrenoceptor Agonists ◽  
Inhaled Salbutamol

1. Airway, metabolic and cyclic nucleotide responses to intravenous salbutamol were measured in five patients with mild asthma who had taken no medication in the week before the study. The studies were repeated after the patient had taken regular inhaled salbutamol for 4 weeks, in doses increasing to 2000 μg daily in week 4. 2. The pretreatment airway, metabolic and cyclic nucleotide responses to salbutamol were similar to those previously reported in normal subjects. These patients therefore did not show evidence of partial β-adrenoceptor blockade. 3. After 4 weeks' salbutamol therapy the airway response to intravenous salbutamol was unchanged. 4. The glucose, pyruvate and adenosine 3′:5′-cyclic monophosphate (cyclic AMP) responses to intravenous salbutamol were depressed after regular salbutamol administration. The dose-response curve for non-esterified fatty acids and insulin, though displaced downwards, did not indicate an impaired response to salbutamol since the shape was unchanged. There was no significant change in the lactate, glycerol and total ketone response. 5. This study confirms that tissues differ in the ease with which they develop resistance to β-adrenoceptor agonists. Asthmatic airways appear to be relatively protected from developing resistance when compared with other tissues in asthmatic patients and when compared with the airways of normal subjects.

scholarly journals Non-esterified fatty acids impair insulin-mediated glucose uptake and disposition in the liver

Diabetologia ◽  
2004 ◽  
Vol 47 (7) ◽  
pp. 1149-1156 ◽  
Author(s):  
P. Iozzo ◽  
R. Lautamaki ◽  
F. Geisler ◽  
K. A. Virtanen ◽  
V. Oikonen ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Glucose Uptake ◽  
Esterified Fatty Acids

PLASMA NON-ESTERIFIED FATTY ACID LEVELS IN HYPOPITUITARY SUBJECTS

1966 ◽  
Vol 35 (1) ◽  
pp. 107-115 ◽  
Author(s):  
T. C. B. STAMP
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Oral Administration ◽  
Normal Subjects ◽  
Control Group ◽  
Insulin Administration ◽  
Plasma Nefa ◽  
Prolonged Fasting ◽  
Fat Mobilization ◽  
Esterified Fatty Acids

SUMMARY Changes in the plasma levels of non-esterified fatty acids (NEFA) in a group of patients with proven hypopituitarism have been compared with those found in control subjects during prolonged fasting, after the injection of insulin and after the oral administration of glucose with and without the previous administration of insulin. During a 4 hr. prolongation of an overnight fast plasma NEFA levels increased at a significantly slower rate in the patients with hypopituitarism. The intravenous injection of insulin was followed by a prompt fall in NEFA levels in the control group, and by a rapid return to or above original values. The recovery was consistently and markedly impaired in the patients with hypopituitarism and this abnormality differentiated them more clearly from the normal subjects than the abnormality in their plasma sugar response to insulin. The patients with pituitary hypofunction had a flat plasma sugar curve after the oral administration of glucose, but there were only minor differences from the normal plasma NEFA levels. Previous insulin administration impaired glucose tolerance in normal subjects and resulted in a more rapid late return of NEFA levels than after the administration of glucose alone. This late rise in NEFA did not occur in the hypopituitary group. The results obtained support the concept that pituitary integrity is required for normal fat mobilization. The consistency of the changes suggests that tests based on plasma NEFA measurements may provide a useful indirect means of diagnosing pituitary hypofunction.

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