Total Catecholamine Concentration Research Articles

Androgen Responses to Sprint Exercise in Young Men

The purpose of this study was to investigate the effects of a 6-month sprint training program on plasma androgens and catecholamine (CA) concentrations in response to a 6 s sprint in adolescent boys [training group (TG), n=6; control group (CG), n=6]. A 6 s-sprint test was performed on a cycle ergometer before and after training (Pre-T and Post-T, respectively). Plasma total testosterone (TT), bioavailable testosterone (BT), and CA concentrations were measured at rest, after a warm-up, immediately after a 6 s-sprint, and during the recovery (i. e. 5 and 20 min). After training period, plasma TT concentrations increased significantly at the end of the sprint and during the recovery in the TG. No effects for sampling times and period were observed in BT levels. Plasma TT concentrations after 5 min of recovery were positively correlated with the corresponding values of plasma lactate (La) concentrations and with post-6 s-sprint plasma adrenaline (A) concentrations (r=0.52; p<0.01 and r=0.61; p<0.01, respectively). These results suggest that sprint training increases plasma TT concentrations in response to sprint exercise in adolescent boys. Plasma A and plasma La concentrations increases in response to sprint exercise could be involved in this elevation of plasma TT concentrations.

Influence of Tumor Size on Anesthetic Management for Pheochromocytoma Resection

The relationship between tumor size and the complexity of anesthetic management was studied using several values: plasma catecholamine concentrations, requirement of vasoactive agents, surgical time, blood loss, plasma glucose concentrations, and hemodynamic variables. Ten patients with clinical and laboratory diagnosis of pheochromocytoma were prospectively studied. Each anesthesia was maintained using inhalational anesthetic agents. Control of arterial blood pressure (ABP), heart rate (HR), and pulmonary artery blood pressure (PABP) was attempted with only titrating the inhalational anesthetics and adenosine triphosphate (ATP). If the titration of both the inhalational anesthetic and ATP failed to control ABP, HR, or PABP, then phentolamine, propranolol, trinitroglycerine, or norepinephrine was additionally used. Tumor weight was significantly correlated with amount of blood loss, surgical time, duration of ATP requirement, maximal dose of ATP infusion used, maximal plasma glucose concentration, and plasma total catecholamine concentration. However, the tumor weight was not correlated with hemodynamic variables. Patients who required propranolol generally had a significantly larger tumor than those who did not. In conclusion, surgical removal of large pheochromocytoma required more complicated anesthetic management than that of small pheochromocytoma.

Influence of tumor size on anesthetic management for pheochromocytoma resection.

The relationship between tumor size and the complexity of anesthetic management was studied using several values: plasma catecholamine concentrations, requirement of vasoactive agents, surgical time, blood loss, plasma glucose concentrations, and hemodynamic variables. Ten patients with clinical and laboratory diagnosis of pheochromocytoma were prospectively studied. Each anesthesia was maintained using inhalational anesthetic agents. Control of arterial blood pressure (ABP), heart rate (HR), and pulmonary artery blood pressure (PABP) was attempted with only titrating the inhalational anesthetics and adenosine triphosphate (ATP). If the titration of both the inhalational anesthetic and ATP failed to control ABP, HR, or PABP, then phentolamine, propranolol, trinitroglycerine, or norepinephrine was additionally used. Tumor weight was significantly correlated with amount of blood loss, surgical time, duration of ATP requirement, maximal dose of ATP infusion used, maximal plasma glucose concentration, and plasma total catecholamine concentration. However, the tumor weight was not correlated with hemodynamic variables. Patients who required propranolol generally had a significantly larger tumor than those who did not. In conclusion, surgical removal of large pheochromocytoma required more complicated anesthetic management than that of small pheochromocytoma.

Changes in free and total catecholamine concentrations in plasma in patients undergoing coronary artery bypass grafting under high-dose fentanyl anesthesia.

We measured free and total catecholamine in ten patients undergoing coronary artery-bypass grafting under high-dose fentanyl (93.9 +/- 2.2 microg.kg(-1), mean +/- SE) anesthesia. Arterial blood samples were obtained: 1) before induction of anesthesia (control), 2) 1 min after intubation, 3) 1 min after skin incision, 4) 1 min after median sternotomy and, 5) just before termination of cardiopulmonary bypass (CPB). The concentrations of free and total catecholamine were measured by HPLC using fully automated analyzer, 8030-TOHSO. Free and total catecholamine concentrations did not change significantly before CPB. At the termination of CPB, however, the levels in free dopamine, norepinephrine and epinephrine all increased several fold as compared with control. Similarly, total norepinephrine and epinephrine also increased at the end of PCB, while total dopamine did not change. Present results indicated that 1) the measurement of free CAs is more significant than the measurement of total CAs for the assessment of sympathoadrenal responses to surgical stimuli, and that 2) high-doses of fentanyl produce hemodynamic stability by suppressing sympathoadrenal responses elicited by the usual surgical procedures. However, stress triggered by CPB could not be suppressed totally by fentanyl even with high dose.

The effect of tranquillizers on the immediate responses to repeated capture and handling of boma-kept impala

1. 1. The effects of tranquillizers on the physiological responses of wild boma-kept impala ( Aepyceros melampus melampus) to repeated capture and handling were investigated. 2. 2. The study involved three separate trials in which both a treatment and a control group of impala were confined in a boma and caught regularly for blood sampling. 3. 3. The plasma and blood were analysed for variables associated with the stress response namely, lactate, glucose, total protein, total lipid, cortisol and total catecholamine concentrations as well as haematocrit and osmolality. 4. 4. In each trial, both groups displayed increased lactate, glucose, cortisol, total catecholamines, osmolality and haematocrit but there was no difference between control or treatment groups. 5. 5. These results indicate that none of the tranquillizers used was effective in suppressing the physiological responses of boma-kept impala to capture and handling. However, the observable sedatory effects of these drugs may be beneficial in the initial adaptation of wild impala to confinement if they are not subjected to additional Stressors.

Catecholamine content of intracerebral adrenal medulla grafts

The rotational behavior which is produced by substantia nigra lesions can be decreased by adrenal medulla grafts adjacent to the denervated striatum. Perhaps these grafts secrete dopamine that diffuses into the striatum. In the present study, we measured concentrations of catecholamines in adrenal medulla grafts as compared with the normal adrenal medulla. The grafts were found to have high but extremely variable concentrations of dopamine. In hosts with substantia nigra lesions, concentrations of dopamine in the adrenal medulla grafts were decreased. Substantia nigra lesions, however, tended to increase concentrations of epinephrine in the grafts, while norepinephrine and total catecholamine concentrations were not significantly affected. It is concluded that at least some adrenal medulla grafts contain concentrations of dopamine sufficient to account for their behavioral effects.

Properties of norepinephrine N-methyltransferase from pigeon brain

Epinephrine cocentration in pigeon hypothalamus was higher on an absolute basis and as a percentage of total catecholamine concentration than in other regions of pigeon brain or in rat hypothalamus. Norepinephrine N-methyltransferase (NMT; the epinephrine-forming enzyme) from pigeon brain had Km values for S-adenosyl-L-methionine and L-norepinephrine of 24 ± 1 and 101 ± 4 μM, respectively. The enzyme was inhibited by excess L-norepinephrine and by several arylalkylamines that earlier had been identified as NMT inhibitors with the enzyme from mammalian brain and adrenal medulla. These results indicate that pigeon brain NMT is similar to that in mammalian brain and adrenal glands and can be inhibited by agents previously used to deplete brain epinephrine selectively in rats. The use of pigeons as experimental subjects in studies on the possible role of epinephrine-forming neurons in behavior is suggested.

Rat brain synaptic vesicles: uptake specificities of [3H]norepinephrine and [3H]serotonin in preparations from whole brain and brain regions.

AbstractA fraction containing neurotransmitter storage vesicles was isolated from rat whole brain and brain regions, and the uptakes of [3H]norepinephrine and [3H]serotonin were determined in vitro. Norepinephrine uptake in vesicle preparations from corpus striatum was higher than in prep arations from cerebral cortex, and uptake in vesicles from the remainder (midbrain + brainstem + cerebellum) was intermediate. The Km for norepinephrine uptake was the same in the three brain regions, but the regions differed in maximal uptake capacity by factors which paralleled total catecholamine concentration rather than content of norepinephrine alone. Intracisternal administration of 6‐hydroxydopamine, but not of 5,6‐dihydroxytryptamine, reduced vesicular norepinephrine uptake, and pretreat‐ment with desmethylimipramine (which protects specifically norepinephrine neurons but not dopamine neurons from the 6‐hydroxydopamine) only partially prevented the loss of vesicular norepinephrine uptake. These studies indicate that uptake of norepinephrine by rat brain vesicle preparations occurs in vesicles from norepinephrine and dopamine neurons, but probably not in vesicles from serotonin neurons. Uptake of serotonin by brain vesicle preparations exhibited time, temperature and ATP‐Mg2+ requirements nearly identical to those of norepinephrine uptake. The affinity of serotonin uptake matched that of serotonin for inhibition of norepinephrine uptake, and the maximal capacity was the same for serotonin as for norepinephrine. Norepinephrine, dopamine and reserpine inhibited serotonin uptake in a purely competitive fashion, with Kis similar to those for inhibition of norepinephrine uptake. Whereas 5,6‐dihydroxytryptamine treatment reduced synaptosomal serotonin uptake but not vesicular serotonin uptake, 6‐hydroxydopamine reduced vesicular serotonin uptake in the absence of reductions in synaptosomal serotonin uptake. Thus, in this preparation, serotonin appears to be taken up in vitro into catecholamine vesicles, rather than into serotonin vesicles.

Lack of relation between venous plasma total catecholamine concentrations and ventricular arrhythmias after acute myocardial infarction.

Electrocardiographic tracings were recorded continuously to monitor ventricular tachycardia and R-on-T and R-on-apex-T ventricular premature beats, and repeated estimations of venous plasma total catecholamine concentrations were carried out in 26 patients admitted to a coronary care unit with acute myocardial infarction. No relation existed between the increased catecholamine concentrations found in these patients and the incidence of ventricular arrhythmias occurring six to 48 hours after the onset of symptoms.

Rapid semiautomated method for the differential determination of urinary catecholamines.

A semiautomated method is presented for the determination of adrenaline and noradrenaline by a combination of the trihydroxyindole procedure for total catecholamines and a new procedure for the specific direct determination of adrenaline without interference from noradrenaline at physiological levels. This new procedure involves the reaction of adrenaline with alkaline thiosemicarbazide to produce a fluorophor of acceptable stability for use in automated procedures. Its structure is as yet unknown. The within-batch standard deviation for the trihydroxyindole and alkaline thiosemicarbazide procedures respectively were 0.005 mumol/24h at a concentration of 0.368 mumol/24h and 0.012 mumol/24h at a concentration of 0.133 mumol/24h. The between-batch standard deviations of the two procedures were respectively 0.018 mumol/24h at a concentration of 0.388 mumol/24h and 0.015 mumol/24h at a concentration of 0.111 mumol/24h. Normal ranges for urine are presented for 24 healthy ambulant laboratory staff. The total catecholamine concentration (calculated as adrenaline) was 0.452 +/- 0.069 mumol/24/ (SD), range 0.349-0.616 mumol/24h. Using the alkaline thiosemicarbazide procedure, the normal range which was determined for adrenaline was 0.100 +/- 0.054 mumol/24h, range 0.022-0.207 mumol/24h. Noradrenaline calculated by difference was 0.355 +/- 0.081 mumol/24h, range 0.195-0.497 mumol/24h.

Circulating Catecholamines and Systolic Time Intervals in Labile and Sustained Hypertension

1. Average supine circulating total catecholamine concentrations were found to be higher than the normal range in about 50% of patients with labile hypertension and in about 30% of patients with sustained essential hypertension. 2. These higher resting concentrations were mainly due to an increase in adrenaline in labile hypertension and to an increase in noradrenaline in sustained hypertension. 3. Patients with elevated catecholamine concentrations were also characterized by a higher heart rate, by an increased myocardial contractility and by greater hypotensive response after treatment with beta-adrenoreceptor blocking agents. 4. These studies suggest the existence of sub-groups of hypertensive patients with increased sympathetic tone.

The Effect of Antilipolytic Agents on Cyclic AMP, Free Fatty Acid and Total Catecholamine Concentrations in Plasma

Plasma concentrations of adenosine 3':5' cyclic monophosphate (cyclic AMP) and free fatty acids have been measured in 15 patients with acute myocardial infarction and in 6 dogs given infusions of isoprenaline. Plasma total catecholamines were also estimated in the patients. Inhibition of adipose tissue lipolysis with a nicotinic acid analogue did not decrease plasma cyclic AMP concentrations, either in the patients or when elevated in the dogs, thus suggesting that this tissue is not a major source of the nucleotide in plasma.

Semi-automated method for the differential determination of plasma catecholamines.

A method is described for the estimation of adrenaline and noradrenaline in a 5 to 10 ml plasma sample.A batch technique of adsorption and elution from alumina is used and the final estimation is carried out using an automated fluorimetric technique based on the trihydroxyindole method. Fluorescence is stabilized first by thioglycollic acid to give noradrenaline concentrations only and then by ascorbic acid to give the total catecholamine concentration. The results of a number of catecholamine analyses are given.

Left ventricular performance and blood catecholamine levels in the isolated heart.

Left ventricular performance in the isolated heart of the dog as expressed by the peak systolic intraventricular pressure was observed during control periods when the heart was perfused with blood from a healthy anesthetized donor and after the donor was removed and the heart perfused with blood oxygenated by isolated lungs. Heart rate, coronary perfusion pressure, ventricular end-diastolic pressure, and stroke volume were maintained constant throughout. While the heart was perfused with blood from a donor, ventricular performance showed no tendency to decline, although coronary flow invariably increased. On removing the donor and perfusing the heart with blood oxygenated by isolated lungs, myocardial performance declined in proportion to the decline in the total catecholamine concentration of the perfusing blood. Restoration of catecholamine levels by infusing epinephrine and norepinephrine also restored left ventricular performance.

Catecholamines in plasma and urine at high altitude.

The concentration of free epinephrine and norepinephrine in plasma and 24-hr urine samples, collected from members of the Dutch Monte Rosa expedition (July 1963) was investigated during 17 days at various altitudes up to 4,560 m. The results indicate that the levels of both plasma and urine catecholamines were elevated during the expedition, the plasma levels reaching a maximum towards the end of the 12 days sojourn at 4,560 m. In general there was a twofold increase in total catecholamine concentration in the samples collected at high altitude as compared to control values at sea level. This difference was due to a significant increase in the norepinephrine concentration; there was little change in epinephrine level. epinephrine and norepinephrine; sympathoadrenal activity Submitted on September 2, 1964

Cytophotometric study on the chromaffin reaction, the iodate reaction and formalin-induced fluorescence as indicators of adrenaline and noradrenaline concentrations in the adrenal medulla.

Variable depletion of adrenal catecholamines was caused in rats by injections of reserpine and muscular work. The intensities of the chromaffin reaction, the iodate reaction and formalin-induced fluorescence in adrenal sections were measured by cytophotometry and compared with chemically determined concentrations of adrenaline and noradrenaline in the adrenal medulla. A close correlation was observed between the optical density of the chromaffin reaction and the total catecholamine concentration, as well as between the intensity of the formalin-induced fluorescence, the optical density of the iodate reaction and the noradrenaline concentration.