Biomedical subjects

H Perrault

Publications and source records attributed to H Perrault.

38 records · Page 3Linked to original sources

PubMed1981

Plasma norepinephrine response to exercise before and after training in humans.

Plasma norepinephrine (NE) concentration was measured by means of a sensitive radioenzymatic assay in blood collected from an antecubital vein in 10 healthy male subjects (37 +/- 2 yr, mean +/- SE). The subjects were evaluated at rest and during exercise before and after a 20-wk training program on bicycle ergometer (three 30-min sessions per week at 80% of maximal heart rate). Following the training program, maximal oxygen uptake increased significantly from 33 +/- 2 to 42 +/- 1 ml . kg-1 . min-1. Resting plasma NE remained unchanged after training (167 +/- 38 before and 185 +/- 29 pg . ml-1 after training). For a given absolute work load (735 +/- 51 kg . m. min-1) the sympathetic nervous response was lower after training as reflected by the decrease in NE concentration (1,371 +/- 286 vs. 687 +/- 64 pg . ml-1). At the same relative work load (heart rate: 158 +/- 5 before and 157 +/- 5 beats . min-1 after training) plasma NE concentration was unchanged after training (1,371 +/- 286 vs. 1,729 +/0 371 pg . ml-1). Results from the present study show that the sympathetic nervous activity is closely linked to the exercise demands and confirm earlier suggestions that it remains constant in relation to the relative work load.

Adult↗

PubMed1980

Electro- and echocardiographic study of the left ventricle in man after training.

Fourteen sedentary middle-aged men underwent a chest X-ray, a 12 lead ECG, a VCG, and an echocardiographic examination prior to and following 5 months of training a moderately severe intensity, on a cycle ergometer. No modification in the X-ray cardiac profile was observed following training. Some electrocardiographic (R wave amplitude in V5 and V6 and Sokolow index: SV1 + RV5 or V6) and vectorcardiographic (maximal QRS vector amplitude, maximal spatial QRS vector, and R wave amplitude) indices of left ventricular hypertrophy were slightly but significantly increased following training. The echocardiographic measurements in diastole (septal and posterior wall thickness, left ventricular internal diameter, and left ventricular mass) were unchanged after training. Results suggest that electrical changes may not provide adequate indications of left ventricular morphological modifications. The lack of echocardiographic evidences of left ventricular hypertrophy suggest that: (1) training does not necessarily induce left ventricular hypertrophy; (2) the large heart sometimes observed in athletes may be the result of a genetic factor or of a prolonged and very intensive training pursued since a very young age, over a number of years; and (3) left ventricular enlargement probably plays a minor role in the increase in aerobic capacity following training.

Echocardiography↗