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PubMed1995

The effect of skin incision followed by alfentanil on catecholamine levels and on the T-wave amplitude of ECG during isoflurane anaesthesia.

Haemodynamic, ECG T-wave amplitude and plasma potassium changes and plasma catecholamine responses to skin incision followed by alfentanil were studied in 24 ASA I patients. Propofol and vecuronium were used without anticholinergics for induction of anaesthesia followed by isoflurane in 02/air. End-tidal isoflurane concentration was kept constant (0.7%) for 30 min before the skin incision. Five min after the skin incision alfentanil 30 mu g kg-1 was given. Blood samples for catecholamines and plasma potassium concentrations were drawn from right ventricle of the heart one minute before and after the skin incision and two minutes after alfentanil. Heart rate, systolic and diastolic arterial pressures increased after the skin incision (P < 0.001), and decreased after alfentanil (P < 0.001). Plasma adrenaline and noradrenaline concentrations increased slightly after the skin incision (P < 0.05 and P < 0.01, respectively). Noradrenaline levels continued to increase after alfentanil (P < 0.001) despite totally abolished haemodynamic responses to the skin incision. ECG T-wave amplitude changes, measured as R/T ratio, did not correlate to the changes in plasma catecholamine levels: both rapid increases and decreases in R/T ratio were seen. No plasma potassium changes were seen during the trial. T-wave changes, occurring in seconds after the skin incision, are probably produced by a direct catecholamine release from cardiac sympathetic nerve endings.

Adult↗
PubMed1976

A histochemical investigation of catecholamines in spinal cord injury.

The catecholamine hypothesis of progressive spinal cord necrosis following mechanical trauma was investigated with the histofluorometric method. Forty-four adult mongrel dog were examined as control, L1 crush-injured, and crush-injured with prior T1 total transection groups. In crush injured dogs, catecholamines were present in a 1 cm length of white matter at the crush site, with the greatest accumulation in the deep lateral and ventral funiculi. Gray matter fluorescence was not enhanced. Prior transection did not abolish the intense accumulation of catecholamines at the site of the cord injury. We propose that the catecholamines accumulating at the cord injured site are not central in origin, but represent an uptake mechanism into white matter as a reflection of cord microperfusion.

Animals↗
PubMed1992

Catecholamine synthesizing enzymes in 70 cases of functioning and non-functioning phaeochromocytoma and extra-adrenal paraganglioma.

Immunohistochemical localization of the catecholamine synthesizing enzymes, tyrosine hydroxylase (TH), aromatic L-amino acid decarboxylase (AADC), dopamine-beta-hydroxylase (DBH) and phenylethanolamine N-methyltransferase (PNMT), was investigated in 70 cases of functioning and non-functioning phaeochromocytomas comprising 52 of adrenal and 18 of extra-adrenal origin. Of 59 functioning tumours, 30 were mixed epinephrine and norepinephrine-producing (mixed type) and 29 were norepinephrine-producing tumours. TH, AADC and DBH were detected in all functioning phaeochromocytomas, but PNMT was limited to the mixed-type phaeochromocytomas. Non-functioning phaeochromocytomas were divided into two groups, comprising a complete type, which induced neither elevated plasma catecholamines nor their metabolites in urine, and an incomplete type which exhibited no elevated plasma catecholamines, but showed a slightly high urinary vanillylmandelic acid level. In the non-functioning complete-type tumours, immunoreactive TH was negative, but the incomplete tumours of the adrenal medulla had all four enzymes, and corresponded to a mixed-type phaeochromocytoma. AADC and DBH were present universally in all functioning and non-functioning tumours, including TH-negative tumours. TH is a rate-limiting enzyme of catecholamine biosynthesis and deficiency of TH is an important feature of extra-adrenal non-functioning phaeochromocytomas.

Adrenal Gland Neoplasms↗
PubMed1996

Cortisol and catecholamine kinetics during continuous hemodiafiltration in patients with multiple organ dysfunction syndrome.

OBJECTIVE: To assess the influence of continuous hemodiafiltration (CHDF) on cortisol and catecholamine kinetics in multiple organ dysfunction syndrome. DESIGN: Consecutive clinical study. SETTING: General intensive care unit of a university hospital. PATIENTS: Ten adult patients with multiple organ dysfunction syndrome requiring CHDF. MEASUREMENTS AND RESULTS: A total of 40 samples were collected during CHDF for cortisol and catecholamine assays. The clearances for cortisol, epinephrine, norepinephrine and dopamine were 2.5 +/- 1.7 ml/min, 26.3 +/- 2.7 ml/min, 16.7 +/- 4.2 ml/min and 26.3 +/- 2.6 ml/min (Mean +/_ SE), and their daily extractions were 1.8 +/- 0.2 mg/day, 11.4 +/- 4.8 micrograms/day, 1.0 +/- 0.1 micrograms and 2.3 +/- 0.3 micrograms/day, respectively. There were no significant changes in blood cortisol and catecholamine levels during CHDF conducted for 48 h. CONCLUSIONS: The cortisol and catecholamine losses during CHDF were small and unlikely to lead to hemodynamic disturbances.

Blood Glucose↗
PubMedDate not supplied

Noncompetitive catecholamine-antagonism of acetylcholine in the sympathectomized mammalian ventricular myocardium.

The effect of the vagus transmitter on the ventricular myocardium varies qualitatively as well as quantitatively in different warm-blood species. In the ventricular myocardium of birds (duck, hen), a part of the acetylcholine sensitivity remains even after catecholamine depletion. In contrast, the inhibitory effects of acetylcholine on the ventricular myocardium of mammals (rat, guinea pig, cat, dog, man) depend on the activity of the sympathicus. In the chemically sympathectomized (6-OH-DA) cat ventricular myocardium, a cholinergic innervation is, histochemically, clearly demonstrable. Correspondingly significant effects of endogenous (i.e. releasable by field stimulation) and exogenous acetylcholine can be seen if the contraction force is enhanced by exogenous catecholamines. This preparation is, therefore, a good model for the demonstration of a catecholamine antagonism of acetylcholine. Using this model, on the basis of dose-response relationships, it is possible to demonstrate that a noncompetitive catecholamine-antagonism of acetylcholine indeed exists in the mammalian ventricular myocardium independent of a cholinergically mediated reduction in the norepinephrine release.

Acetylcholine↗
PubMed1994

Extraversion as a modifying factor in catecholamine and behavioral responses to ethanol.

Individual differences in catecholamine response to stress and ethanol were tested in extraverts and introverts on the basis of Eysenck's drug postulate claiming that introverts would be less susceptible to sedative drugs like ethanol. Forty-four healthy males received either 0.8 g/kg ethanol mixed into a drink of caffeine-free cola or a respective placebo and were tested with a stressful mental arithmetic task before and 40 min after the intake of the drink. Plasma catecholamines were determined from blood samples drawn at five defined intervals from an indwelling cannula and self-ratings on deactivation, relaxation, and anxiety were obtained as well as quality and quantity of performance in the arithmetic task. Results showed that there was no difference in catecholamine stress responses between introverts (Ex -) and extraverts (Ex +) before the drink, but that the intake of the fluid (both ethanol and placebo) resulted in higher norepinephrine (NE) increases in Ex - than in Ex +. The combined effects of ethanol and stress yielded larger responses of longer durations in Ex - than in Ex +. The concomitant psychological changes showed larger reductions in anxiety and increases in relaxation as well as larger decrements in quality of performance (% errors) in introverts in spite of their higher catecholamine increases. Thus, the predictions on the basis of arousal theory could not be verified experimentally and the drug postulate has to be modified in the sense that introverts probably have a higher depletion of NE in the central nervous system under physical but not under mental stress which is reflected by higher levels in the plasma and respective decreases in performance and activation.

Adult↗
PubMed1997

Expression of catecholamine-synthesizing enzymes, peptidylglycine alpha-amidating monooxygenase, and neuropeptide Y mRNA in the rat adrenal medulla after acute systemic nicotine.

The expression of catecholamine-synthesizing enzymes in the adrenal medulla is upregulated in parallel by stress and pharmacological treatments. In this study we examined whether a neuropeptide and its processing enzyme are regulated in parallel with catecholamine enzyme genes after drug treatment. Because the main effect of stress on the adrenal medulla is via splanchnic nerve stimulation of nicotinic receptors, we used nicotine to stimulate the medulla and visualized expression of catecholamine enzyme genes, the medullary peptide neuropeptide Y (NPY), and the neuropeptide-processing enzyme peptidylglycine alpha-amidating monooxygenase (PAM) by in situ hybridization quantified by image analysis of autoradiographic images. Rats received a single injection of nicotine (0, 1, or 5 mg/kg sc). Six hours later, rats were transcardially perfused. Free-floating adrenal gland sections were hybridized with 35S-labeled cDNA probes for tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DBH), phenylethanolamine N-methyltransferase (PNMT), PAM, and NPY. Nicotine treatment upregulated the expression of TH, PNMT, and NPY genes in a dose-dependent fashion. Small but nonsignificant increases were observed in DBH and PAM mRNA levels. These results suggest that common transcriptional activation mechanisms may upregulate both catecholamine and neuropeptide synthesis in the adrenal medulla after nicotinic stimulation.

Adrenal Medulla↗
PubMed1995

Dietary copper supplementation increases the catecholamine levels in genetically obese (ob/ob) mice.

The interactive relationship between Cu deficiency and depressed synthesis of certain neurotransmitters has been recognized. To investigate the effects of dietary Cu supplementation on the catecholamine levels in genetically obese mice, male obese (ob/ob) mice and their lean (+/?) counterparts were administered either a control diet (4.0 mg/kg) or a Cu-supplemented diet (50 mg/kg) for 4 wk. The ob/ob mice that were fed a control diet showed lower liver and higher plasma levels of Cu. Depressed levels of plasma and brain catecholamines were also found in ob/ob mice that were fed the control diet. The ob/ob mice that received a Cu-supplemented diet showed significant increases in the levels of catecholamine in the plasma and brain. This study showed that catecholamine levels in ob/ob mice can be increased by dietary Cu supplementation. However, the interaction between Cu and sympathetic nervous activity in obesity was not elucidated in this study.

Animals↗
PubMed2004

Survey of the use of catecholamines by French physicians.

OBJECTIVE: The objective of the study was to perform a descriptive approach of the current use of catecholamines by French physicians. DESIGN: A questionnaire of 12 questions with 4 items established by a group of French intensivists. POPULATION: French physicians from 433 departments working in the following practicing areas: intensive care unit (ICU), emergency department, and pre-hospital setting. MEASUREMENTS: Responding physicians were asked about the catecholamine that they would select in various clinical settings. RESULTS: The response rate was 82%. Of the responding physicians, 277 (78%) worked in an ICU, 28 (8%) in an emergency department, and 21 (6%) in a pre-hospital setting. Dobutamine was chosen for patients with cardiogenic shock by 90% of the respondents. Norepinephrine was the first choice agent as vasopressor in patients with septic shock in 52% of the cases. Dopamine was selected in a clinical setting requiring an optimization of regional blood flow, as in the concept of high-risk surgical patients. Dopexamine was used as a second or third choice agent to improve regional blood flow and cardiac output. The indications of epinephrine for anaphylactic shock and cardio-circulatory arrest were obvious for more than 90% of responding physicians. CONCLUSION: A lack of standardization appears in the use of catecholamines by French physicians, particularly for improvement of regional circulation and management of high-risk surgical patients. Guidelines that define the place of each catecholamine in these settings are required to improve the quality of prescription.

Catecholamines↗
PubMed2007

Stimulation of catecholamine synthesis via activation of p44/42 MAPK in cultured bovine adrenal medullary cells by milnacipran.

Milnacipran is a serotonin noradrenaline reuptake inhibitor (SNRI) and is used clinically as an antidepressant. We report here the effect of milnacipran on catecholamine synthesis in cultured bovine adrenal medullary cells. Incubation of adrenal medullary cells with milnacipran (300 ng/ml, 1,065 nM) for 20 min resulted in a significant increase in 14C-catecholamine synthesis from [14C]tyrosine, but not from [14C]DOPA, whereas the selective serotonin reuptake inhibitors (SSRIs), paroxetine (300 ng/ml, 800 nM) and fluvoxamine (300 ng/ml, 691 nM), had little effect. Milnacipran, but not paroxetine or fluvoxamine, increased the activity of tyrosine hydroxylase, the rate-limiting step of catecholamine biosynthesis, in a concentration-dependent manner (100-300 ng/ml, 355-1,065 nM). U0126 (1 microM), an inhibitor of p44/42 mitogen-activated protein kinase (MAPK) kinase, abolished the stimulatory effects of milnacipran on tyrosine hydroxylase activity. Furthermore, incubation of cells with milnacipran (30-100 ng/ml) for 5 min activated p44/42 MAPK, whereas paroxetine and fluvoxamine did not. The present findings suggest that milnacipran activates tyrosine hydroxylase and then stimulates catecholamine synthesis through a p44/42 MAPK-dependent pathway in cultured bovine adrenal medullary cells.

Adrenal Medulla↗
PubMed1997

Catecholamines and dihydroxyphenylalanine in metamorphosing larvae of the nudibranch Phestilla sibogae Bergh (Gastropoda: Opisthobranchia).

The content of catecholamines and dihydroxyphenylalanine in larvae of the nudibranch Phestilla sibogae was analyzed by high-performance liquid chromatography with electrochemical detection. Dihydroxyphenylalanine, norepinephrine and dopamine were identified in larvae of all ages examined (5 through 12 days post-fertilization). Dihydroxyphenylalanine could be accurately quantified only in larvae of ages 8 through 12 days, when its average concentration increased from 0.62 to 6.71 x 10(-2) pmol micrograms protein-1. Between ages 5 and 12 days dopamine rose from 0.081 to 0.616 pmol microgram protein-1, and norepinephrine from 0.45 to 2.17 x 10(-2) pmol micrograms protein-1. Dihydroxyphenylalanine, dopamine and norepinephrine were also measured at different stages of metamorphic progress in 10- to 12-day larvae. Dihydroxyphenylalanine increased by a factor of 2.4 between the onset and completion of metamorphosis, but levels of dopamine and norepinephrine remained stable. One millimolar alpha-methyl-DL-m-tyrosine, an inhibitor of catecholamine synthesis, inhibited natural metamorphosis and depleted endogenous norepinephrine and especially dopamine, respectively, to 75% and 35% of control values. The existence of unexpectedly high levels of catecholamines in metamorphically competent larvae, and the association of catecholamine depletion with inhibition of metamorphosis, indicate that these compounds may participate in the control of gastropod development.

Animals↗
PubMed2003

Kinetics of catecholamines and potassium, and heart rate during exercise testing in obese subjects. Heart rate regulation in obesity during exercise.

BACKGROUND: Obesity is characterised by a marked insulin resistance which involves an abnormal regulation of K(+) uptake and metabolism. Less is known about the effect of physical exercise on K(+) kinetics. AIM OF THE STUDY: To assess plasma catecholamines and potassium levels and their relationship with cardiac activity during a physical effort up to exhaustion in young obese subjects. METHODS: Blood samples for epinephrine (E), norepinephrine (NE), potassium (K+) and heart rate (HR) were collected at the end of every step during a progressive cycloergometric test up to exhaustion in twelve obese subjects (6 males, aged 26+/-2, BMI 39.9+/-1) and twelve normal subjects (6 males, aged 28.2+/-2, BMI 22+/-1). In every subject anaerobic threshold (AT) was detected. RESULTS: In obese subjects plasma catecholamines rose faster but had a lower peak in correspondence of maximal work-loads, with respect to controls. Catecholamines had a linear correlation in the obese group and a quadratic one in the control group when plotted vs O(2) consumption. The increase of plasma potassium was less in obesity than in control. CONCLUSIONS: During physical exercise K(+) and catecholamines kinetics differ significantly in obese subjects vs normals and they may justify a less prompt cardiac response at the higher work-loads and a lower work capacity. The present data can be interpreted in the light of the insulin resistance syndrome of obesity, which causes an abnormal regulation of the Na-KATPase and of K(+) channels during physical exercise. The results of the present study may be relevant to nutritionists when suggesting physical exercise to obese subjects.

Adult↗
PubMed2005

Catecholamine-synthesizing enzymes in the adult and prenatal human testis.

Catecholamines play functional roles in the mature and developing mammalian testis but the cell types responsible for their local synthesis are still controversially discussed. Here, we demonstrate that four enzymes involved in the biosynthesis of catecholamines, namely, tyrosine hydroxylase (TH), aromatic amino acid decarboxylase (AADC), dopamine beta-hydroxylase (DBH) and phenylethanolamine- N-methyltransferase (PNMT), are expressed in Leydig cells of the human testis. Tyrosine hydroxylase, the key enzyme of the biosynthesis of catecholamines, was localized to Leydig cells both at the transcript level (by RT-PCR analyses and by in situ hybridization assays) and at the protein level (by immunoblotting and by immunohistochemistry). The other enzymes were also demonstrated in Leydig cells by RT-PCR and immunohistochemical analyses. The presence of TH, AADC, DBH, and PNMT in human Leydig cells was found, in addition, by immunohistochemical approaches carried out on sections from prenatal human testes. Thus, the present study identifies the Leydig cells as the presumed sites of catecholamine production in both the mature and fetal human testes and further supports the previously recognized neuroendocrine characteristics of this cell type.

Aged↗
PubMed2004

Leptin, catecholamines and free fatty acids related to reduced recovery delays after training.

The aim of this study was to observe the effects of exercise on plasma free fatty acids (FFA), the catecholamines (adrenaline, noradrenaline, dopamine) and leptin levels, before and after training, to determine their possible influence on the improvement of the regulation of energy homeostasis. Eleven trained rowers performed two exercise sessions (S1, S2) of 90 min each (70-75% V(.)O(2peak)), separated by a 36-week period of intense endurance training. Leptin, FFA and catecholamine plasma concentrations were measured both at the beginning and at the end of S1 and S2, and after recovery periods of 2 and 24 h. Training modified leptin levels in S2 as opposed to S1 ( P<0.001); in S1 leptin levels remained lower after a 24 h recovery whereas they returned to pre-exercise levels in S2. The respiratory exchange ratio was significantly reduced in S2 compared to S1 ( P=0.018). The FFA and leptin levels were correlated after a 24-h recovery in S1 ( r=0.87; P=0.0082), and after a 2-h recovery in S2 ( r=0.66; P=0.021). All data were expressed as the means and standard errors of the mean. In the two sessions, an immediate exercise effect was observed on the levels of the catecholamines, which did not persist after recovery. This training effect was apparent for all catecholamines in response to exercise, particularly on noradrenaline ( P=0.0006). The noradrenaline and leptin levels were correlated after a 2-h recovery in S2 ( r=-0.74; P=0.0042). We conclude that the effect of training on the response of noradrenaline to exercise seems to be involved in the delay in the normalization of leptin levels. We suggest that the amplitude of the noradrenaline response to exercise induced an increase in fat use and a rapid leptin recovery after exercise. The sensitivity of leptin to changes in the fat stores may be improved after training. Both training effects seemed to be involved in the reduction of the recovery time observed for the leptin levels.

Adult↗
PubMed2003

Hemodynamic and catecholamine responses during tracheal intubation using a lightwand device (Trachlight) in elderly patients with hypertension.

PURPOSE: Tracheal intubation using a lightwand device (Trachlight) should minimize hemodynamic change by avoiding direct-vision laryngoscopy. We evaluated hemodynamic and catecholamine responses during tracheal intubation using a Trachlight in elderly patients with hypertension. METHODS: Twenty-six hypertensive patients aged over 65 years undergoing orthopedic surgery were randomly divided into two groups, group L (n = 13) and group T (n = 13). Anesthesia was induced with fentanyl (2 microg x kg(-1)) and propofol (1.5 mg x kg(-1)), and then muscle relaxation was obtained with vecuronium (0.15 mg x kg(-1)). The trachea was intubated with either a Macintosh laryngoscope (group L) or a Trachlight (group T). Hemodynamics, plasma catecholamine concentrations, and arterial blood gases were measured before the induction of anesthesia (T0), before tracheal intubation (T1), immediately after tracheal intubation (T2), and 3 min after tracheal intubation (T3). RESULTS: The intubation time was shorter in group T than in group L (12.6 +/- 1.7 vs 23.5 +/- 2.9 s, mean +/- SE; P < 0.01). Compared with the preinduction (T0) value, systolic blood pressure (SBP) showed a significant decrease at T1 and T3 in group L and at T1, T2, and T3 in group T. The heart rate (HR) and plasma norepinephrine (NE) concentration showed no change in either group throughout the time course, whereas the plasma epinephrine (E) concentration showed a significant decrease at T2 and T3 in both groups. The mean values of the rate-pressure product (RPP: HR x SBP) were less than 15000 after tracheal intubation in both groups. There was no significant difference in hemodynamic or catecholamine responses between groups at any point. No patient had ischemic ST-T changes in either group. CONCLUSION: A lightwand has no advantage over a laryngoscope in terms of hemodynamic and plasma catecholamine responses to tracheal intubation in elderly patients with hypertension, despite a shorter intubation time.

Aged↗
PubMed2004

Role of catecholamines in glucagon-induced thermogenesis.

The present work was undertaken in order to investigate whether the observed thermogenesis following glucagon injection requires the participation of catecholamines. Our experiments aim at studying the effects of intraperitoneal injection of glucagon on metabolic rates, plasma catecholamine and fuel metabolites in guanethidine-treated ducklings reared at thermoneutrality (25 degrees C). The chronic guanethidine treatment induced a marked decrease in catecholamines levels in peripheral tissues (heart, muscle and intestine) but not in adrenals. At thermoneutrality, intraperitoneal injection of glucagon had lower thermogenic effects in guanethidine-treated compared to control ducklings. Glucagon injection elicited a concomitant increase of plasma norepinephrine, metabolic rate and energy metabolites in control ducklings, whereas in guanethidine-treated ducklings, the plasma catecholamines and metabolic rate did not undergo any consistent change. The thermogenic action of glucagon in birds involves at least the mobilization of lipids and catecholaminergic system stimulation.

Adipose Tissue↗
PubMed1998

The role of catecholamines in desmopressin induced locomotor stimulation.

Central and peripheral administration of DDAVP increase locomotor activity in rats in doses that alter brain dopamine neurochemistry. In order to delineate the role of catecholamines in this behavioural effect of DDAVP, the effects of different catecholamine manipulating agents on DDAVP-induced locomotor stimulation were studied in rats. The catecholamine depleting agent reserpine (5 mg/kg), administered alone or together with the catecholamine synthesis inhibitor alpha-methyltyrosine (250 mg/kg), completely prevented the locomotor stimulatory effect of DDAVP. The dopamine D1 receptor antagonist Sch-23390 (0.01 and 0.03 mg/kg) significantly antagonized the DDAVP-induced locomotor stimulation when administered in the higher dose, that also produced a significant reduction of locomotor activity per se, whereas the dopamine D2 receptor antagonist raclopride (0.08 and 0.16 mg/kg) had no significant effect. The two dopamine blockers administered together produced a significant, dose-dependent reduction of DDAVP-induced locomotor stimulation, while controls were not significantly affected. Also the alpha-adrenoceptor antagonist phenoxybenzamine decreased the DDAVP-induced locomotor stimulation in a dose (20 mg/kg) that did not influence locomotor activity in controls, and, finally, administration of Sch-23390, raclopride and phenoxybenzamine antagonised the DDAVP-induced effect in a dose combination that failed to influence locomotor activity per se. In vivo microdialysis experiments in awake, freely moving rats indicated that DDAVP increases dopamine overflow in the nucleus accumbens, a brain area of importance for initiation of locomotor activity, by approximately 25%, as compared to baseline levels. Taken together, these results indicate that the central stimulatory action of DDAVP involves granula-mediated dopamine release and subsequent activation of dopamine D1 and D2 receptors, and that alpha-adrenoceptors possibly also are involved.

Adrenergic alpha-Antagonists↗
PubMed1989

Exercise-related changes in serum catecholamines and potassium: effect of sustained exercise above and below lactate threshold.

Plasma potassium and catecholamines exhibit rapid shifts during exercise testing, particularly when exercise intensity exceeds lactate threshold. To assess changes that may occur during sustained exercise, we studied 10 healthy men to determine the effect of 20 minutes of exercise at 25 W above lactate threshold (ALT) and 20 minutes of exercise at 25 W below lactate threshold (BLT). Both conditions showed elevation of catecholamines at end exercise compared to baseline, but catecholamine levels ALT were significantly higher than the levels BLT (2270 +/- 190 versus 900 +/- 230 pg/ml norepinephrine, p less than 0.001; 509 +/- 69 versus 150 +/- 18 pg/ml epinephrine, p less than 0.001). This difference persisted at 2 minutes of recovery (1620 +/- 130 versus 590 +/- 60 pg/ml norepinephrine, p less than 0.001; 216 +/- 31 versus 98 +/- 16 pg/ml epinephrine, p less than 0.001). Both conditions resulted in a significant elevation in potassium at end exercise compared to baseline, but the potassium levels ALT were significantly higher than the levels BLT (1.1 +/- 0.1 mEq/L versus 0.5 +/- 0.1 mEq/L, p less than 0.001. The fall in potassium in the immediate post-exercise period was significantly greater following exercise ALT (-0.8 +/- 0.1 mEq/L versus -0.2 +/- 0.1 mEq/L, p less than 0.001). Thus sustained exercise slightly ALT resulted in a significant potassium flux and very elevated catecholamine levels. Avoiding these metabolic stresses by exercising BLT may decrease chances for exercise-related arrhythmia or other cardiac dysfunction in susceptible patients.

Adult↗