H. Weicker

Electrochemical detection of catecholamines in urine and plasma after separation with HPLC.

The catecholamines in plasma and urine were determined by electrochemical detection after separation on a HPLC column RCM 100 C 18. Linear calibration plots of epinephrine, norepinephrine and dopamine have been obtained in the range expected to appear in urine or plasma. Coefficients of variation (0.5 to 10%), recovery rates (60 to 80%) and the standard deviation were satisfactory, whereas plasma dopamine showed a greater variation (10-15%). The values ascertained by this technique were compared with those determined by the radioenzymatic assay of Da Prada et al. They showed a good correlation for norepinephrine r = 0.92, p less than 0.001 and epinephrine r = 0.80, p less than 0.01, but less for dopamine r = 0.1. Experimental details of isolation from plasma with Al2O3 adsorption and desorption with HClO4, and from urine with ion exchange chromatography on Bio-Rex 70 and elution with boric acid are described. Technical modifications which improve the method are reported. The optimized assay could reliably be employed in investigations of more than 3000 urine and plasma samples obtained from patients and athletes before and after exercise.

Cardiopulmonary adjustment and metabolic response to maximal and submaximal physical exercise of boys and girls at different stages of maturity.

SummaryCardiopulmonary and metabolic variables were investigated at maximal and submaximal bicycle ergometer exercises in 41 swimmers of both sexes, 8–18 years old.

A new gas chromatographic method for determination of amino acid levels in human serum.

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Comparison of sympatho-adrenergic regulation at rest and of the adrenoceptor system in swimmers, long-distance runners, weight lifters, wrestlers and untrained men

O2 max and

Effect of acute and chronic exercise on plasma amino acids and prolactin concentrations and on [3H]ketanserin binding to serotonin2A receptors on human platelets.

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Sustained noradrenaline sulphate response in long-distance runners and untrained subjects up to 2 h after exhausting exercise

O2 max·HR−1 were higher in boys than in girls and increased with maturity, while