Urinary excretion of free noradrenaline and adrenaline related to age, sex and hypertension in 265 individuals

Urinary excretion of free noradrenaline and adrenaline during 24 h in 265 individuals was determined and related to sex, age, and hypertension as one indicator of the average sympathetic drive. Noradrenaline was found to correlate positively with age in healthy individuals. Noradrenaline and adrenaline were lower in healthy women than in men during the first half of life expectancy. Catecholamine excretion was similar in men and women in the second half of life expectancy. In hypertensive individuals, catecholamine excretion was slightly higher in the first half, and significantly higher in the second half of life expectancy. We assume that the differences in catecholamine excretion can contribute to the sex-and age-related differences in incidence of cardiovascular diseases, such as hypertension and coronary heart disease.

[Primary orthostatic hypotension]

We studied a 25-year-old man suffering from primary orthostatic hypotension whose blood pressure decreased to 65/45 mm Hg during orthostasis and to 95/70 mm Hg during ergometric exercise (50 and 100 watt), and whose heart rate responses were inadequate. Resting catecholamine levels were within the normal range and did not show any significant increase related to orthostasis or to ergometric exercise. Hypersensitivity was observed to low doses of intravenous noradrenaline and isoproterenol. Specific binding of 3H-Yohimbine to intact platelets revealed a normal number of alpha-2-adrenoreceptors in agreement with the adrenaline-induced platelet aggregation in vitro, which was, however, in contrast to hypersensitivity to noradrenaline. Specific 3H-Dihydroalprenolol binding to intact polymorphonuclear leucocytes revealed an increased beta-2-adrenoreceptor density in agreement with hypersensitivity to Isoproterenol. Prescription of Fludrocortison improved orthostatic hypotension.

Free plasma catecholamines, heart rates, lactate levels, and oxygen uptake in competition weight lifters, cyclists, and untrained control subjects

Responses of free plasma noradrenaline and adrenaline were evaluated in 10 competition cyclists, 8 competition weight lifters, and 9 untrained control subjects during exhaustive, incremental cycling. Ergometric performance and oxygen uptake ability were 403 +/- 20 W and 65.8 +/- 4.7 ml X kg-1 for the cyclists, 294 +/- 42 W and 47.2 +/- 4.6 ml for the weight lifters, and 296 +/- 40 W and 46.7 +/- 9.4 ml for the control subjects. At 100- and 150-W levels, noradrenaline was significantly lower in cyclists and weight lifters, and in cyclists also at 200- and 250-W levels, related to the other groups. No significant noradrenaline differences were seen between the three groups at their respective exhaustion levels. Compared with the control subjects, adrenaline responses were lower in cyclists and weight lifters at all identical work loads. The weight lifters showed the lowest levels of all three groups, even at their exhaustion level, which indicates an alteration of the adrenaline-noradrenaline ratio. Dynamically and statically trained subjects exhibit a similar training-related control of sympathetic activity. An increased vagal tone, however, only occurs in conjunction with dynamic endurance training.

Capillary-venous differences of free plasma catecholamines at rest and during graded exercise

Levels of free plasma catecholamines were simultaneously determined in 10 cyclists using capillary blood from one ear lobe and venous blood from one cubital vein. Catecholamine concentrations were higher in the ear lobe blood than in the venous blood at rest and during graded exercise. Average differences amounted to 1.7 nmol X 1(-1) (dopamine), 2.1 nmol X 1(-1) (noradrenaline) and 1.9 nmol X 1(-1) (adrenaline) at rest and increased only to 8.8 nmol X 1(-1) for noradrenaline during exercise. We assume that higher concentrations of dopamine and adrenaline in the capillary blood point to a significant neuronal release of these catecholamines, similar to noradrenaline. Catecholamine concentrations in capillary blood may better reflect sympathetic drive and delivery of catecholamines to the circulation than the concentrations in venous blood.

Cytoimmunological monitoring in acute rejection and viral, bacterial or fungal infection following transplantation

This study assessed the ability of immunomonitoring to differentiate between acute cardiac rejection and viral, bacterial or fungal infections, using data of thirty-five cyclosporine treated heart and heart-lung transplant recipients. Peripheral blood samples were analyzed daily for 20 days, then three times weekly until the patient's discharge. Later, peripheral blood was examined every fourteen days on an outpatient basis. White blood cells were counted and differentiated. A mononuclear concentrate was obtained by the Ficoll-Hypaque gradient and centrifugation method, and cytocentrifuged onto slides. The cells were stained by a five minute method. Percentages of lymphocytes, prelymphoblasts, lymphoblasts, large granular lymphocytes and monocytes were calculated. When activated cells were detected, aliquots of the mononuclear concentrate were labeled using monoclonal antibodies. In these thirty-five patients, more than 60 acute rejection episodes were diagnosed by the cytoimmunological method. Acute rejection was characterized by a significant rise of the number of leukocytes, lymphocytes, prelymphoblasts and lymphoblasts. The T-lymphocyte population increased while the B-cells remained normal. Ninety-five percent of all acute rejection episodes were diagnosed using cytoimmunological parameters. During viral infection more than 20% of the mononuclear cells were large granular lymphocytes and the OKT4/OKT8 ratio was less than one. During bacterial and fungal infections the B-lymphocytes increased to 40% of the mononuclear cells. In addition, juvenile polymorphs appeared in the mononuclear concentrate and the OKT4/OKT8 ratio was within normal limits (1.5 to 2.5).(ABSTRACT TRUNCATED AT 250 WORDS)

[Energy yield during physical exertion]

Every energy demanding process in the skeletal muscle is associated with the use of adenosinetriphosphate, the essential muscular high-energy phosphate. ATP is rephosphorylated by ADP (= adenosine diphosphate) and this process depends on the type, intensity and duration of the physical exercise. At the beginning of a vigorous physical exercise utilization of intramuscular ATP and phosphocreatine is predominant (= anaerobic-alactacide energy yielding). Then the ATP rephosphorylation based on the conversion of glycogen and glucose to lactate, especially by an exercise duration till 2 min (= anaerobic-alactacide energy yielding). Toward this duration or if the exertion intensity at start has been below 60 to 70% of maximal physical performance, ADP is rephosphorylated during oxidative phosphorylation by the skeletal muscle mitochondria using glycogen, glucose or free fatty acids as energy fuel. Training, age and sex may influence anaerobic and aerobic energy-yielding as well as metabolism and ultrastructure of skeletal muscle.

Plasma catecholamine and blood lactate cumulation during incremental exhaustive exercise

Six healthy male subjects performed two different incremental treadmill tests. Test 1 started at a velocity of 8 km.h-1 and was increased by 2 km.h-1 steps until subjective exhaustion was reached. The running time was 3 min per step with 30-s interruptions between two successive steps. In test 2, identical work loads were imposed on the subjects. However, there were 30-min recovery periods between two successive exercise steps. Heart rate, oxygen uptake (only in test 1), blood lactate, and free plasma catecholamine levels were simultaneously estimated during both testings and additionally at the end of each 30-min recovery period in test 2. Subjects reached 57 +/- 6 ml.kg-1. min-1 oxygen uptake. Only slight lactate and catecholamine differences were observed between both tests at moderate work loads. Lactate levels (+30%) as well as noradrenaline and adrenaline responses (+60%-90%) were higher in the cumulative experiment (test 1) at work loads corresponding to 70%-80% of the oxygen uptake capacity as compared to the noncumulative testing procedure (test 2). A further increase of these differences to approximately 50% (lactate), 156% (noradrenaline), and 165% (adrenaline) has to be considered to be near the exhaustion level. In conclusion, during incremental treadmill exercise in a cumulative design, a significant cumulation effect leads to an overproportional increase of lactate and catecholamine levels at submaximal--maximal work loads.

[Excretion of free dopamine, noradrenaline and adrenaline in 190 males in relation to age and blood pressure]

The 24-h urinary excretion of free catecholamines was evaluated in: 62 healthy and 20 hypertensive (primary hypertension, stage 1 and 2) male subjects, less than or equal to 39 years of age, and in 64 healthy and 44 hypertensive (primary hypertension, stage II and III) male subjects greater than or equal to 40 years of age. Noradrenaline excretion correlates positively with the age, based on the date of all 190 subjects (r = 0.29, P less than 0.001) and for the 126 healthy subjects (r = 0.37, P less than 0.001), however not for the 64 hypertensive patients. Adrenaline and dopamine excretion does not show any significant correlation with the age of the investigated subjects, neither for all 190 subjects nor for the different groups. The noradrenaline-adrenaline ratio also correlates positively with the age (r = 0.28, P less than 0.001, n = 190). The younger hypertensives (less than or equal to 39 years of age) show a slightly but not significantly higher noradrenaline excretion; this, however, is significantly higher in the group of older hypertensive subjects (P less than 0.05; greater than or equal to 40 years of age). No significant differences are recognizable for adrenaline and dopamine excretion between normotensive and hypertensive subjects.

[Conjugated plasma catecholamines are lower in power athletes at rest and in physical work than in untrained probands]

Lower levels of free plasma catecholamines, noradrenaline and adrenaline were recently described in statically trained athletes under identical work loads during incremental cycling as compared with untrained control subjects. These differences point to a control of sympathetic activity by static training. Theme of the presented investigation is the question of additional training-dependent alterations of the conjugated plasma catecholamines in statically trained athletes. Eight competition weight lifters (21 +/- 2 years of age; 73 +/- 10 kg body weight) and seven untrained healthy control subjects (26 +/- 6 years; 75 +/- 4 kg) were investigated. The conjugated catecholamines were radioenzymatically determined as the difference between total and free catecholamines. The investigated subjects performed an incremental, exhaustive bicycle ergometric test in an upright body position. Before exercise, the levels of conjugated plasma dopamine (P less than 0.10), of conjugated noradrenaline (P less than 0.001) and conjugated adrenaline (P less than 0.10) are 2-3 times lower in statically trained athletes than those of the control subjects. The conjugated catecholamines did not show any significant changes during exercise, the significant differences between both groups (P less than 0.05-P less than 0.01) were therefore also observed during exercise. In contrast to the free plasma catecholamine responses, the conjugated catecholamine fractions are seen as indicators of long term alterations of the sympathetic activity.

[Free and conjugated plasma catecholamines, lactate behavior and oxygen uptake at rest and in staged physical exertion as well as alpha receptor density in intact thrombocytes in trained athletes]

The influence of chronic static training on free and conjugated plasma catecholamines was investigated in 8 statically trained athletes (21 +/- 2 years of age) at rest and during incremental ergometric cycling. Plasma catecholamines are seen as biochemical indicators of the over-all sympathetic activity. Alpha-2-adrenoreceptors were additionally determined as one parameter of the organism's sensitivity to catecholamines. During modest and heavy exercise, free plasma noradrenaline and adrenaline are comparably low in statically and endurance trained athletes. They are lower than in untrained subjects. During exhaustion, however, free adrenaline responses of the statically trained athletes only amount to 30-50% of the concentrations observed in endurance trained athletes and untrained subjects. Free plasma dopamine and conjugated plasma catecholamines do not show any significant changes during ergometric exercise. Free and conjugated catecholamines correlate positively. Positive correlations are also observed between blood pressure and plasma catecholamines. These correlations however are clearer between conjugated catecholamines and blood pressure. This is also recognizable for the negative correlation between alpha-2-receptor density on intact platelets (1078 +/- 323 binding sites per cell) and conjugated catecholamines. In conclusion, statically trained athletes also show an alteration of sympathetic tone (catecholamines) comparable to that observed in endurance trained athletes. Maximal adrenaline responses however are lower in statically trained athletes than in endurance trained or untrained subjects. The alpha-adrenoreceptor density on intact thrombocytes seems to be increased in statically trained athletes.

[Changes in sympathetic activity in 18 postinfarct patients following a year of exercise therapy]

18 male post-infarction patients (56 +/- 9 years) were investigated before and after 1 year of controlled physical therapy. Results were compared with those observed in 7 healthy male control subjects (47 +/- 6 years). Left-ventricular impairment of the investigated patients corresponded haemodynamically to stages I and II of the Roskamm-Reindell classification, based on a Swan-Ganz catheter. The influence of physical therapy on plasma catecholamine levels was evaluated; free plasma catecholamines are seen as reference indicators of sympathetic activity. Cycling performance capacity (supine position) of the patients increased from 101 +/- 25 watt to 131 +/- 24 watt. Before and after physical therapy, maximal heart rate responses were similar (121 +/- 17 as compared with 119 +/- 16 min-1). After physical therapy, maximal noradrenaline responses were 16% lower, adrenaline responses down by 25%, and mean arterial blood pressure was 14 mm Hg lower. At identical work-load (50 watt level), reductions after physical therapy amounted to 25% (noradrenaline), 41% (adrenaline), 16% (heart rate), and 21 mm Hg (mean arterial blood pressure).

[Reversible orthostatic hypotension during vincristine therapy]

A 69-year old patient with high-grade malignant lymphoma experienced severe orthostatic hypotension during vincristine therapy. The symptoms disappeared when vincristine treatment was discontinued. The mechanism of the orthostatic hypotension is discussed.

Age- and exercise-related sympathetic activity in untrained volunteers, trained athletes and patients with impaired left-ventricular contractility

To study the influence of training, aging and left-ventricular contractility on the sympathetic nervous system, responses of plasma catecholamines and density of adrenoreceptors on intact blood cells were evaluated in 21 dynamically trained subjects, 8 statically trained weight lifters, 15 healthy young and 15 old control subjects, and 55 post-infarction patients. Plasma catecholamines are indicators of the overall sympathetic tone, while the density of adrenoreceptors is a cellular indicator of the sensitivity to catecholamines. Static and dynamic training result in lower catecholamine response at identical work loads during incremental ergometric tests. Higher density of beta 2 receptors on intact leucocytes and higher sensitivity to isoproterenol are seen in the dynamically trained test subjects. Higher density of alpha 2 receptors on intact thrombocytes is found in the weight lifters. Despite the training-dependent control of the sympathetic activity bradycardia occurs only in endurance-trained subjects, indicating an additionally increased vagal control. The exercise-related tachycardia of the weight lifters, on the other hand, points to an insufficient vagal control of the cardiac sinus rate. Decrease of physical fitness, as related to aging, a deficit in physical training and impaired left-ventricular contractility are connected with a higher sympathetic activity at identical work loads and a lower beta-receptor density on intact blood cells and, in cardiac patients, on myocardial cells as well (Bristow et al. 1982). Changes in the sympathetic system may amplify the age- and disease-dependent decrease of the cardiac function.(ABSTRACT TRUNCATED AT 250 WORDS)

[Is the alpha adrenergic receptor density increased in intact thrombocytes in non-isometric trained athletes?]

Alpha-adrenoreceptors were determined as an equivalent to 3H-dihydroergocryptine (DHE) specifically bound on intact thrombocytes in five untrained volunteers (I), eight non-staticly trained sportsmen (II), and eight intensively staticly trained athletes (III). Bmax was 933 +/- 363 (I), 982 +/- 373 (II), and 1796 +/- 539 fmol DHE X 10(-9) thrombocytes (III). KD was 1.28 +/- 0.49 (I), 2.94 +/- 1.12 (II), and 3.58 +/- 1.07 nmol X l-1 (III). The number of binding sites per cell amounted to 561 +/- 202 (I), 589 +/- 224 (II), and 1078 +/- 323 (III). The thrombocytes of the staticly trained athletes showed a significantly higher number of binding sites and a slightly higher affinity (KD) than the other groups (p less than 0.01). However, a wide range of overlapping has to be considered. The biologic significance of these results and their transferability to other organs are open at present. It is the question whether an altered adrenoreceptor density may be one factor of a higher prevalence of hypertension in staticly trained athletes on which our research group has reported recently.

Amino acid, ammonia and neurotransmitter concentrations in hepatic encephalopathy: serial analysis in plasma and cerebrospinal fluid during treatment with an adapted amino acid solution

We evaluated changes of advanced liver disease and hepatic encephalopathy on the concentrations of amino acids (AA) and ammonia in plasma and cerebrospinal fluid (CSF) and of the neurotransmitters norepinephrine, dopamine and 5-hydroxytryptamine (5-HT) as well as the 5-hydroxyindole acetic acid (5-HIAA) in CSF before and at the end of a 3-day period of treatment with infusions enriched with branched chain amino acids (BCAA). The subjects studied were 13 patients with alcoholic cirrhosis and hepatic encephalopathy stages 1-3 (n = 8) and stage 4 (n = 5). The patients in coma stages 1-3 recovered during the treatment (survivors), those in coma stage 4 died before the study period was finished (non-survivors). The data emerging from this study show: Alterations of AA concentrations are much more pronounced in the CSF than in the plasma. In the case of tryptophan the alterations in plasma and CSF were inverse. Before the treatment the CSF-plasma ratios of the concentrations of BCAA and aromatic amino acids (AAA) are increased reflecting an activated transport of both the BCAA and AAA through the blood-brain barrier. High dose BCAA nearly normalized CSF concentrations and CSF-plasma ratios of AAA assuming that the treatment brought about an effective competition of cerebral uptake between BCAA and AAA. The CSF concentrations of ammonia and glutamine decreased significantly during treatment while the plasma concentrations changed only moderately. As to the neurotransmitters, only the concentrations of 5-HT and its metabolite 5-HIAA correlated with the clinical picture and with the concentration of their precursor AA.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of alternating cycle lengths on refractoriness of the His-Purkinje system

The effects of alternating cycle lengths (bigeminal rhythm) on His-Purkinje system refractoriness were studied in 14 patients using His bundle and right bundle recordings. Programmed atrial stimulation at constant cycle length (method I) was scanned using the atrial extrastimulus technique (A2) and compared with an atrial cycle length of identical duration coupled to A2 on alternate beats (method II). The results showed that (a) despite shorter cycle length of the His-Purkinje system with method II due to effect of A2 on atrioventricular nodal conduction (699 +/- 90 vs. 743 +/- 87 ms, P less than 0.001), the relative refractory period of the His-Purkinje system was always longer with method II (463 +/- 52 vs. 440 +/- 43 ms, P less than 0.001). A similar increase also occurred in effective refractory period of the His-Purkinje system; (b) while functional right bundle branch block occurred in eight patients and functional left bundle branch block in two patients with method I, functional right bundle branch block occurred in all 14 patients and left bundle branch block in seven patients with method II; (c) in two patients where both functional right and left bundle branch block occurred with method I this never was manifest at identical degree of abbreviation of His-Purkinje system cycle length but was manifest at identical abbreviation in each of seven patients with method II; (d) site of conduction delay and/or block during functional right bundle branch block was always proximal, i.e., between the His bundle and right bundle recordings with both methods. During method II this resulted in shortening of the subsequent right bundle cycle length relative to the subsequent His bundle (and of necessity left bundle) cycle length. The finding of increased His-Purkinje system refractoriness despite shorter preceding cycle length of the His-Purkinje system during atrial bigeminy has never been previously described and suggests that classical concepts of His-Purkinje system behavior may require revision in this setting. Secondly, during atrial bigeminy the occurrence of alternating functional bundle branch block cannot be accounted for solely by the degree of abbreviation of His-Purkinje system cycle length, but may be explained by a relative shortening of the next ipsilateral bundle branch cycle length in the bundle manifesting block.

[Sympathetic activity in patients with coronary insufficiency]

Twelve healthy control subjects, 9 cardiac patients with normal central hemodynamics, 9 patients with impaired left-ventricular contractility during exercise, and 10 patients with impaired contractility and coronary insufficiency (anginal pain and ST-segment depression of ECG) were investigated. Central hemodynamic values (Swan-Ganz catheter) as well as free plasma catecholamines noradrenaline and adrenaline were simultaneously determined at rest and during incremental exercise. At rest, no significant differences were observed between all groups. The cardiac patients with normal central hemodynamics also did not show any significant differences in their plasma catecholamine responses during exercise as compared with healthy control subjects. Patients with impaired left-ventricular contractility, indicated by a significantly increased pulmonary capillary wedge pressure, as reference value of increased left ventricular end-diastolic pressure, both with negative and positive indicators of coronary insufficiency during exercise, showed significantly higher noradrenaline levels at identical work loads than control subjects. However, adrenaline responses were only significantly higher in patients with positive indicators of coronary insufficiency during exercise. The noradrenergic responses may be triggered by a borderline reduction of cardiac output as well as by increased pressures in the low-pressure system. The over-proportional adrenergic responses may be an indicator of precordial anginal pain and anxiety. This reaction is seen to be significant for a further increase in myocardial oxygen demands and anginal pain.

Effect of amiodarone on conduction and refractoriness of the His-Purkinje system in the human heart

Although the antiarrhythmic aspect of amiodarone has been extensively studied, its effects on His-Purkinje system conduction and refractoriness have not been systematically investigated in human beings. In 24 patients, anterograde His-Purkinje system conduction (HV intervals) and variables of His-Purkinje system refractoriness using the ventricular extrastimulus (V2) technique were analyzed before and after long-term therapy with amiodarone. The mean duration of amiodarone therapy at the time of repeat study was 16.2 +/- 7.7 weeks (range 11 to 42). The anterograde His-Purkinje system conduction time (HV interval) measured 49.6 +/- 9.5 ms (range 40 to 80) before and 60.6 +/- 10.7 ms (range 45 to 90) after amiodarone (p less than 0.005). During retrograde refractory period studies, the longest V1V2 interval at which a retrograde His bundle potential (H2) emerged from the V2 electrogram (relative refractory period of the His-Purkinje system) was consistently longer after amiodarone as compared with the control period (376.4 +/- 46.6 versus 318.8 +/- 33.1 ms, p less than 0.005). Similarly, the shortest and longest His-Purkinje system conduction times ( V2H2 interval) at comparable V1V2 intervals were uniformly and significantly prolonged after administration of the drug. Amiodarone also abolished macroreentry in the His-Purkinje system in six of the nine patients who showed such reentry during the control period. The effective refractory period of the ventricular myocardium was also increased from a mean of 227.1 +/- 13.9 to 259.2 +/- 20.2 ms (p less than 0.005) in this series of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma catecholamines, beta-adrenergic receptors, and isoproterenol sensitivity in endurance trained and non-endurance trained volunteers

Six male non-endurance trained subjects (S) and six marathon runners (M) underwent graded treadmill exercise (T) and isoproterenol stimulation (I; 2 and 4 microgram X min-1). beta-adrenergic receptor density was additionally determined as the amount of 3H-Dihydroalprenolol (DHA) specifically bound on intact polymorphonuclear leucocytes. Heart rate, VO2 uptake, lactate, plasma noradrenaline, and adrenaline were estimated during T. Heart rate, stroke volume, cardiac output, as well as lactate, glucose, free fatty acids (FFA), and glycerol levels in the blood were determined during I. M showed the known training-dependent responses during T, such as lower heart rates, lactate levels, and plasma catecholamines at identical work loads, as well as higher VO2 max than S. I-induced cardiac output increase was quite similar in both groups. Stroke volume, however, increased significantly in M and stayed constant in S. Lactate decreased (S), glucose increased significantly (M), glycerol increased similarly in both groups, FFA rise was less marked in S. I-induced stroke volume response (I) may be indicative of a more economic regulation of heart work in M than S. Lactate decrease and less marked FFA increase, as observed in S, may be the result of a somewhat higher cardiac energy demand, dependent on less economic heart work. Higher DHA-binding as observed in M, as well as stroke volume response and glucose increase, may be indicators of a training-dependent rise in sensitivity to catecholamines. The unsolved question is, however, to what extent beta-receptor responses in intact blood cells are significant for receptor behavior in other organs.

Functional characteristics of retrograde conduction in a pacing model of "endless loop tachycardia"

A pacing model was designed that stimulated "endless loop tachycardia," a complication found in the new generation of DDD (atrioventricular [AV] universal) pacemakers. The functional characteristics of the train of ventricular impulses simulating endless loop tachycardia were studied during both AV sequential pacing and basic ventricular drive. AV sequential pacing, by causing a decrease in ventriculoatrial (VA) conduction time of the first beat of the endless loop tachycardia, was associated with a decrease in the cycle length at which VA block occurred in 9 of 12 patients. The site of block was the His-Purkinje system in 4 of these 12 patients and the AV node in the remaining 8. At a cycle length with 1:1 VA conduction, a steady state VA conduction time was achieved in 2 to 4 beats (VA conduction time accommodation). The pattern of such accommodation depended on the site (His-Purkinje system versus AV node) of the maximal conduction delay. The steady state VA conduction time itself was altered with AV sequential pacing in patients showing His-Purkinje system delay, but not in patients with AV nodal delay. The results suggest that in most patients, the cycle length of VA block and the longest steady state VA conduction time will depend on the retrograde conduction time of the first beat of the tachycardia. In addition, pharmacologic measures to prevent or terminate endless loop tachycardia will have to take into account the fact that both the His-Purkinje system and the AV node can be the site of initial block.

[Incidence of hypertension in 810 male sportsmen]

Blood pressure was recorded at rest and during exercise (n = 577) in 810 male sportsmen. Larger subgroups included 125 cyclists, 98 long-distance runners, 90 cross-country skiers, 108 players of various ball games, 25 weight-lifters, and 29 swimmers. At rest, hypertension was observed in 3.8% and borderline hypertension in 7.8% of the sportsmen investigated. When blood pressure responses during exercise were also included, values were increased by 28% to 4.9% (hypertension) and by 26% to 9.8% (borderline hypertension). In the sportsmen investigated, the age range 14-29 years was overrepresented. The age-corrected prevalence was 5.4% (hypertension) and 11.1% (borderline hypertension) at rest. The prevalence of increased blood pressure in sportsmen was about half of the prevalence expected for the total population (p less than 0.05). The low incidence of hypertension in sportsmen may be due to physical training as well as to genetic factors. Increased blood pressure was significantly more frequent in swimmers and weight-lifters than in the other investigated subgroups. In these two sports, unfavorable training-specific factors may compensate for the possible beneficial effects of physical training.

Facilitation of ventricular tachycardia induction with abrupt changes in ventricular cycle length

The effect of abrupt short-to-long changes in cycle length (CL) on the postulated reentrant circuit of ventricular tachycardia (VT) was evaluated. This was performed using single and double ventricular extrastimuli in a group of 21 patients clinically suspected of having VT in whom VT could not be induced at comparable or shorter constant CLs. A second group of 10 patients without suspected VT was similarly studied. Compared with constant CLs of equal or shorter duration preceding the single or double ventricular extrastimuli, abrupt short-to-long CL changes resulted in (1) initiation of sustained VT in 13 of 21 patients in whom VT could not be induced at constant CLs despite the use of shorter S1S3 by 66 +/- 17 ms; (2) increased incidence of initiation of sustained VT after the V3 phenomenon resulting from macroreentry within the His-Purkinje system (Re-HPS); (3) a small but higher incidence of sustained VT due to sustained Re-HPS; and (4) no induction of sustained or nonsustained VT with either method in the second group of patients. These results provide additional support for reentry as the basis for sustained ventricular tachyarrhythmias. Abrupt short-to-long CL changes may be effective for initiating sustained VT in patients at risk for these arrhythmias.

[Comparative clinical studies on parenteral and oral premedication in childhood with special regard to the volume and acidity of the gastric juice]

90 children of age between 1 and 10 years who were scheduled for adenotomy were randomized into 3 premedication-groups. Group 1 received no premedication, group 2 chlorprothixene 1 mg/kg i.m. and group 3 chlorprothixene 2 mg/kg orally. Prior to induction of anaesthesia 63.3% of the unpremedicated children were anxious or crying, in contrast to 23.3% of the children given oral or i.m. premedication. With respect to the reaction on venepuncture with a Butterfly G 23, there was no significant difference between the groups. The volume of gastric acid (median values) was 0.056 ml/kg in group 1, 0.063 ml/kg in group 2, and 0.068 ml/kg in group 3, with a pH of 2.0, 1.5 and 2.0 respectively. One hour after operation 44.8% of the children in group 1, 92.6% in group 2 and 84.6% in group 3 were calm or sleeping. Premedication definitively improves the pre- and postoperative management of children. We now recommend oral chlorprothixene for the premedication of children because the effect of this oral premedication is equivalent to i.m. application, and the oral route has no influence on the quantity or acidity of gastric contents.

[Determination of beta-receptors on intact polymorphonuclear leukocytes in autologous plasma]

The binding of tritium labelled radioligand dihydroalprenolol was investigated on live polymorphonuclear leukocytes of 6 endurance trained (VO2 max. 65.7 +/- 2.0 ml/kg . min), and 9 non-endurance trained subjects (VO2 max. 52.0 +/- 4.0 ml/kg . min). The specific binding of dihydroalprenolol is seen as an indicator of the beta-receptor density. The specific binding of dihydroalprenolol is defined as the difference between the total binding and that amount of dihydroalprenolol that could not be displaced. The leukocytes were reincubated for the binding studies in their autologous plasma. The specific binding of dihydroalprenolol on live polymorphonuclear leukocytes shows a levelling off behaviour at a concentration of approximately 2 nmol/l dihydroalprenolol in trained as well as in untrained subjects. The specific binding amounts to about 85% (0.1 nmol/l dihydroalprenolol) to 51% (2.0 nmol/l dihydroalprenolol) of the total binding. Based on Scatchard analysis, Bmax was determined as 41.2 fmol/10(7) cells (trained subjects) and 21.6 fmol/10(7) cells (untrained subjects). KD is 0.44 nmol/l dihydroalprenolol (untrained subjects), and 0.49 nmol/l dihydroalprenolol (trained subjects). The beta-adrenergic binding sites are approximately 1300 (untrained subjects), and 2500 binding sites/cell (trained subjects). The specific binding of dihydroalprenolol on live polymorphonuclear leukocytes is significantly higher in trained than in untrained subjects. This training dependent change in beta-receptor density may be an indicator of an increased sensitivity to catecholamines.

Correlations between laboratory testing and distance running performance in marathoners of similar performance ability

Correlations between distance running performance and laboratory testing were examined in 11 marathoners of similar fitness (VO2max 66.4 +/- 1.7 ml/kg X min). They performed a graded treadmill test and a subsequent 30 km cross-country run. Heart rate, oxygen intake, blood lactate, and plasma catecholamines were measured during the treadmill test. Lactate equivalent, individual lactate threshold, 4 mmol lactate threshold, submaximum (16 km/h running velocity) lactate behavior, submaximum catecholamine responses, submaximum lactate-catecholamine product, measured VO2max, and extrapolated VO2max were examined for their adequacy in the evaluation of distance running capacity. Race times and free urine catecholamines were estimated in the field experiment. Direct correlations were found between race times and minimum lactate equivalent (r = 0.69), submaximum lactate levels (r = 0.52), submaximum catecholamine responses (r = 0.69), submaximum lactate-catecholamine product (r = 0.79), respectively. Inverse correlations were observed between race times and oxygen intake at individual lactate threshold (r = -0.68), 4 mmol lactate threshold (r = -0.76), measured VO2max (r = -0.71), and extrapolated VO2max (r = -0.63). Further correlations were found between submaximum noradrenaline and lactate behavior (r = 0.53), as well as between noradrenaline and adrenaline responses (r = 0.72). No significant correlation was observed between relative heart volumes or catecholamine excretion and race times.

[Plasma dopamine, noradrenaline and adrenaline response during cardiac and peripheral-muscular exhaustion]

Nine healthy subjects performed 2 different graded bicycle ergometric tests. The 1st test started with 50 watt and was increased 50 watt after 3 min till exhaustion as a model of a metabolic and cardiac exhaustion. The 2nd test started with 100 watt and was increased 50 watt after 15 min till exhaustion as a model of a peripheral-muscular exhaustion. The behaviour of plasma catecholamines, lactate and glucose levels, heart rate and oxygen intake was examined. The results were as following: Performance ability 305 (test 1) and 233 watt (test 2; mean values), work time 17.5 min (1) and 51 min (2), heart rate 185 min-1 (1) and 175 min-1 (2), noradrenaline 30.7 nmol/l (1) and 11.0 nmol/l (2), adrenaline 6.9 nmol/l (1) and 2 nmol/l (2), lactate 9.2 (1) and 6.6 mmol/l (2), glucose 5.6 mmol/l (1) and 4.7 mmol/l (2). During highly intensive dynamic exercise (test 1), three times higher catecholamine and 50% higher lactate responses were observed, than during peripheral-muscular limited endurance exercise (test 2). Above an exercise level of more than 30% VO2 max., nor- and adrenaline increased significantly. Below 50-70% VO2 max. steady-state-behaviour occurred. Above this range unsteady-state-behaviour of plasma catecholamines was observed. Dopamine did not show any significant time and intensity dependent increase. Noradrenaline and adrenaline followed the same initial 1st order elimination kinetic.

[Simultaneous determination of hemodynamics and plasma catecholamines in trained and untrained subjects and patients with contraction disorders of the heart during rest and physical activity]

6 trained (TS) and 7 untrained (US) subjects and 16 patients (P) with left ventricular dysfunction were investigated by means of a Swan-Ganz floating catheter during graded bicycle ergometry in a supine position. 9 P suffered from a myocardial infarction and 10 were known to be hypertensive; 10 suffered from acute coronary insufficiency during exercise. Hemodynamic values, free plasma catecholamines, and heart volume at rest were determined in all cases. The relative heart volume was increased training-dependent in the TS as compared with US and P. In TS stroke volume increased more than in US, whereas in P a heart-rate-dependent adaptation of cardiac output was observed during exercise. In P cardiac output was slightly reduced during exercise and the arteriovenous oxygen difference augmented. Systolic and diastolic pulmonary artery pressure, pulmonary wedge pressure, and peripheral diastolic arterial pressure rose more in P during exercise than in TS and US. TS showed reduced, whereas P showed increased levels of circulating free plasma catecholamines (norepinephrine and epinephrine). Training-dependent changes in hemodynamic values and catecholamine levels were seen as an economic adaptation of the heart to physical stress, and the results in the patients were interpreted as indicating an uneconomic stress adaptation. In patients with disturbed left ventricular function, extracardiac compensatory mechanisms such as enhanced sympathetic activity and increased arteriovenous oxygen difference are necessary for the adaptation to physical stress.

[Beta-adrenergic receptors and plasma catecholamine behavior in trained and untrained athletes]

6 sports students (VO2 max. 54.0 +/- 2.6 ml/kg . min) and 6 marathoners (VO2 max. 65.7 +/- 2.0 ml/kg . min) performed graded treadmill tests. Free plasma catecholamines (noradrenaline and adrenaline), heart rate, lactate were assessed at rest and during exercise. The behaviour of beta-adrenergic receptors of polymorphonuclear leukocytes was estimated additionally before the treadmill test. The maximum running velocity was 14.6 +/- 0.8 km/h (sports students) and 17.3 +/- 0.6 km/h (marathoners). Noradrenaline was approximately 46% (v = 12 km/h) to 67% (v = 14 km/h) lower in the group of marathoners than in sports students; adrenaline showed no or smaller differences between both groups. No significant differences in the plasma catecholamine behaviour occurred between the groups at rest and during maximum exercise. Specific binding of 3H-Dihydroalprenolol to intact cells was higher in the marathoners than in sports students (p greater than 0.01). Scatchard analysis revealed a maximum binding of 21.1 fmol/10(7) cells (sports students) and 35.3 fmol/10(7) cells (marathoners), which indicated approximately 1,300 (sports students) and 2,150 binding sites cell (marathoners). Inverse correlations between noradrenaline (r = -0.63), VO2max. (r = -0.79) and the specific binding of 3H-DHA were observed. The reduction of plasma catecholamines (approximately 46-67%) and the increase in specific binding sites (approximately 67%) were in the same range.(ABSTRACT TRUNCATED AT 250 WORDS)

[Hemodynamics, plasma catecholamine behavior and beta-adrenergic receptor density in trained and untrained subjects and cardiac insufficiency patients]

Swan-Ganz semifloating balloon-tipped catheters were introduced in 6 endurance-trained subjects, 7 untrained volunteers, 29 patients suffering from coronary heart disease, 8 patients with right heart insufficiency induced by chronic obstructive syndromes, and 8 patients with idiopathic congestive cardiomyopathy. All subjects except the patients with resting cardiac insufficiency performed graded ergometric tests during the catheter investigation. Hemodynamic values, plasma noradrenaline and adrenaline (in all subjects), and beta-adrenergic receptor density on intact polymorphonuclear leucocytes (in 6 endurance-trained subjects, 5 untrained healthy volunteers, and 6 patients with left heart insufficiency) were determined. For all subjects investigated, significant correlations were observed between resting plasma catecholamine levels and resting hemodynamic values, such as stroke volume (r = 0.47, p less than 0.001), cardiac output (r = 0.32, p less than 0.05), heart rate (r = 0.37, p less than 0.01), pulmonary vascular resistance (r = 0.52, p less than 0.001), and total vascular resistance (r = 0.40, p less than 0.01). An inverse relationship existed between the resting catecholamine levels and the performance ability. Catecholamine levels were approximately three- to fourfold higher and the beta-adrenergic receptor density approximately two- to threefold lower in patients with left heart insufficiency than in healthy untrained subjects. The plasma catecholamine levels were lower and the beta-adrenergic receptor density approximately 60% greater in trained subjects. The beta-adrenergic receptor density may be a critical dynamic parameter for the modulation of sympathetic effects.

[Sensitivity of free and conjugated plasma catecholamines as indicators of left ventricular contraction disorder of the heart]

Hemodynamic parameters were measured (using a Swan-Ganz semifloating balloon-tipped catheter) and free and conjugated catecholamines were assessed radioenzymatically in plasma from the pulmonary artery in 6 patients (5 postinfarction patients, 1 with idiopathic congestive cardiomyopathy; 56 +/- 7 years old) and 6 healthy control subjects (48 +/- 6 years old). The tests were carried out at rest and during bicycle ergometry in the supine position at incremented work loads. Neither at rest nor during exercise was cardiac output in patients and controls significantly different. The mean capillary wedge pressure (PCPm) was elevated above control values in 1 patient at rest and in all patients during exercise. This may be indicative of impaired left ventricular contractility. The mean ergometric exercise level in patients was 100 w, in the control group 187 w. Conjugated plasma catecholamines showed no exercise dependency, and there were no significant differences between patients and controls. Free dopamine comprised less than 5% of the whole dopamine fraction, free noradrenaline and free adrenaline less than 50% of their fractions. A significant exercise dependency was observed in the case of free noradrenaline and adrenaline in patients and controls; at the same exercise levels, the increase in free noradrenaline was significantly higher in patients than in control subjects (p less than 0.01). During exercise, a correlation between free plasma noradrenaline and PCPm (r = 0.60, p less than 0.01) was observed, but not with certainty in patients (r = 0.27). The free plasma noradrenaline may be seen as a sensitive sympathetic indicator of impaired left ventricular contractility.

The metabolism of radiohafnium in rats and hamsters: a possible analog of plutonium for metabolic studies

The metabolism of radiohafnium (175Hf + 181Hf) was studied in male Sprague-Dawley rats and Chinese hamsters for periods of up to 168 days. The results were compared with similar data for 239Pu in the same rat strain. In rats and hamsters the radiohafnium organ distribution was skeleton greater than skin greater than muscle greater than liver at about 7 days postinjection. Retention of radiohafnium and plutonium was similar in plasma and liver, as were the retention times observed for other organs: Absorption of radiohafnium from the gastrointestinal tract of rats was less than 0.05%. Biochemical studies showed that the radiohafnium was bound mainly to the iron-transport protein, transferrin, in blood plasma and in the liver cytosol of both the rat and the hamster, as has been observed also for plutonium. The metabolic behavior of radiohafnium mimics, to a large extent, that of plutonium, and it is suggested that radiohafnium can serve as a non-alpha-particle-emitting analog of plutonium for metabolic, biochemical, and selected human investigations.

Atrioventricular sequential pacing: differential effect on retrograde conduction related to level of impulse collision

Patients with DDD pacemakers who have intact retrograde conduction are known to be at risk of developing ventricular and "endless loop" tachycardia. To address this problem, a pacing protocol was designed in which V2A2 conduction was assessed in 16 patients during ventricular pacing alone (standard method) and during paced atrioventricular (AV) sequential drive (AV sequential method); the results were then compared. In eight of 16 patients who had intact retrograde conduction with both methods (group 1), the V2A2 intervals were significantly shorter (by 60 to 340 msec) with the AV sequential method. In the remaining eight patients, who demonstrated V2A2 block with the standard method, no V2A2 block occurred with the AV sequential method. In this study, two sets of AV intervals were programmed to produce collision of the two impulses (atrial and ventricular), either in the AV node or the His-Purkinje system (HPS). The site of V2A2 facilitation was related to the site of impulse collision. These results can be explained by earlier excitation by the atrial impulse (of AV node and/or HPS) during AV sequential pacing. However, in some cases it was evident that antegrade propagation of the atrial impulse was responsible for subsequent facilitation. The data suggest that assessment of retrograde conduction in candidates for DDD pacemakers can be made most accurately by the AV sequential method.

Identification of transferrin as the principal plutonium-binding protein in the blood serum and liver cytosol of rats: immunological and chromatographic studies

An analysis of 239Pu-labelled protein complexes in serum and liver cytosol fractions prepared from rats injected intravenously with 239Pu-citrate indicated that among the possible metal-binding proteins, ferritin, transferrin and metallothionein, 239Pu was bound almost exclusively to transferrin. The method employed for the quantitative determination of 239Pu-transferrin was chromatography on immobilized rabbit anti-rat apo-transferrin. There was no evidence that transferrins from serum and liver cytosol are serologically different. The residual blood content of perfused and non-perfused liver was measured using 51Cr-labelled red blood cells and the amounts of blood-derived 239Pu and 239Pu-transferrin in the liver cytosol were calculated. The results are discussed with respect to the possible role of transferrin in the uptake of Pu into cells.

[Two-dimensional stress echocardiography and plasma catecholamine measurements in the evaluation of the physiologically hypertrophied heart]

Two-dimensional stress echocardiography was performed in 8 untrained subjects, 8 long-distance runners, and 8 cyclists. The ergometric investigation was performed with subjects in supine position on a bicycle ergometer with increasing work loads of 50 Watts. At each working level, lactate, norepinephrine, and epinephrine were measured. The long-distance runners and the cyclists had an equal maximum oxygen uptake when tested with treadmill or bicycle ergometer. Absolute and relative heart volumes also showed the same amount of hypertrophy. In spite of this, lactate, catecholamines, and heart rate of the long-distance runners rose earlier during the supine ergometer test. End-diastolic volume and stroke volume in the cyclists increased significantly more (delta EDV = 15%, delta SV = 32%) than in the long-distance runners (delta EDV = 1%, delta SV = 13%) and untrained subjects (delta EDV = 5%, delta SV = 9%). It is assumed that this difference in heart function is caused by diminished sympathetic activity, which is dependent on the aerobic capacity of the working muscles.

Influence of chelating agents on the distribution and excretion of cadmium in rats

The effects of the chelating agents CaNa2-ethylenediaminetetraacetate (EDTA), CaNa3-diethylenetriaminepentaacetate (DTPA), 2,3-dimercaptosuccinic acid (DMSA), 2,3-dimercaptopropanol (BAL), and 2,3-dimercaptopropane-1-sulfonate (DMPS) and of the lipophilic chelating agents Puchel, Puchel-bisamidocysteineethyl ester (Puch-D), and EDTA-bis-amidocysteineethyl ester (EDTA-D) on the distribution of iv injected Cd were studied in male Sprague-Dawley rats. The chelating agents were injected iv as single doses given 10 sec, 1 hr, or 3 hr after 3 mumol/kg Cd + 115mCd. When the chelating agents were injected within 10 sec after the metal, all agents reduced the total body cadmium burden by varying extents ranging from 3% of that in untreated control rats after 0.01 mmol BAL/kg to 94% following 0.1 mmol DTPA/kg. When given 1 hr after Cd injection, the efficacy of all the agents tested was markedly reduced or abolished; at this time only Puchel and Puch-D provoked significant reductions in the body burden of Cd by 21 and 32%, respectively. When treatment was delayed until 3 hr after Cd injection, only Puch-D was able to reduce the body and liver burden of the metal by 14 and 9%, respectively. Combined treatment with Puchel + DTPA, BAL + DTPA, or BAL + DMPS did not enhance Cd removal to an extent greater than that expected from the equivalent dose of the more effective agent of that pair alone. Repeated administration of DTPA, 20 X 0.1 mmol/kg, during 4 weeks by ip or po administration of the same dose in the drinking water over 4 weeks, was no no more effective than the first dose of the chelating agent alone. Gel chromatographic studies of the distribution of Cd among the proteins of the liver cytosol in treated and untreated animals indicate that neither DTPA nor Puchel was able to release Cd from the metallothionein complex.

[Behavior of free catecholamines in blood and urine of ambulance men and physicians during quick responses]

Free urine adrenaline, noradrenaline, (additional free plasma catecholamines in the physicians), and blood lactate were determined in 11 ambulance men and 5 physicians to assess stress during medical service. Stress was evaluated employing a stress index, based on difficulties in driving, traffic, severity of injuries or illness. Emergency cases with seriously injured subjects or reanimation were judged to have a 4-fold higher stress index than routine cases where strong physiological or psychological stress was absent. Urine catecholamines and stress indices were estimated in 3-h intervals. The calculations were based on the stress induced catecholamine concentrations minus the basal excretion during the same 3-h interval. Urine adrenaline and noradrenaline in ambulance men and physicians correlated directly with the stress index, as well as the plasma catecholamines of the physicians. Lactate levels showed similar behaviour and a descriptive direct correlation with the plasma catecholamines. Urine adrenaline increased more--dependent on the stress index--than urine noradrenaline. This over-proportional adrenaline response may be an indicator for the additional psychological stress in emergency cases. Therefore physicians showed--based on the same stress index--a tendency to higher urine adrenaline excretion and blood lactate levels than the ambulance men, which might be the consequence of the overall responsibility of the physicians. Because of the observed catecholamine responses during medical service, coronary insufficiency or hypertension might be contra-indications for participation in the medical service; regular clinical investigations including ergometric tests are advisable.