[Plasma dopamine-beta-hydroxylase activity in pheochromocytoma (author's transl)]. / Activité dopamine-beta-hydroxylase plasmatique après ablation d'un phéochromocytome. Etude chez trois sujets.

In 3 patients with proved pheochromocytoma, circulating catecholamine concentrations, vanillylmandelic acid and total free catecholamine urinary excretion, dopamine-beta-hydroxylase activities in plasma were measured the day before surgery, during the removal of the tumour and postoperatively. Following the removal of the pheochromocytoma, all these parameters declined with a different rate, possibly related to the half-life proper to each molecule. The results showing a decrease in plasma D beta H activities after the removal of the tumors are in good accordance with most authors. The mechanism and the meaning of catecholamines release from non-innervated tumor-cells remain to be elucidated. By considering these three cases, it does not seem that the evolution of D beta H activity after removal of the tumor is dependent upon the fact that the pheochromocytoma releases preferentially either epinephrine or nephinephrine.

[Nutritional, cardiac and adrenergic changes induced by swimming training in rats (author's transl)]. / Etude chez le rat des modifications nutritionnelles, cardiaques et adrénergiques induites par l'entraînement.

The effects of training were investigated in male Sprague Dawley rats group (N), fed ad libitum, by measuring the weight increase and food intake of the animals, biochemical parameters (myocardial triglycerides and glycogen levels), mechanical and metabolic properties of the heart, and adrenergic reactions to swimming stress. An other group of rats remaining sedentary served as control (T). Conditioned rats had been submitted to a one hour test swim 6 days a week for 9 weeks. Gradually additional weights were fixed to the thorax. At the end of training, the load reached 6% of the body weight. Both groups were sacrified by decapitation at the same time, thirty hours after the last swimming session. The study of mechanical performances and metabolic properties was achieved with isolated working heart preparation. Adrenergic reactions of swimming stress were evaluated from plasma, heart and adrenal catecholamine concentrations.

[Determination of the adrenergic response by measurement of catecholamines and activity of dopamine-beta-hydroxylase (D-beta-B) in arterial capillary blood]. / Evaluation de la réaction adrénergique à l'effort par dosage des catécholamines et de l'activité dopamine-beta-hydroxylase (D beta H) dans le sang capillaire artérialisé.

Plasma dopamine-beta-hydroxylase activity and catecholamines (adrenaline and noradrenaline) level in venous blood taken from the cubital vein and in arterialized capillary blood taken from the ear lobe were measured before and after a maximal exercise on a treadmill in 14 healthy untrained volunteers. The authors have shown a good correlation between these parameters in venous blood and those in capillary blood. It is concluded that the determination of plasma dopamine-beta-hydroxylase activity and catecholamines level in arterialized capillary blood could be a valid measure of the sympathetic activity.

Evaluation of sympathoadrenal activity, adrenocortical function and androgenic status in five men during a Himalayan mountaineering expedition (ascent of Mt Pabil, 7,102 m, 23,294 ft).

Sympathoadrenal activity, adrenocortical function and androgenic status were studied in five well-trained mountaineers during the different phases of a mountaineering expedition during the ascent of Mt Pabil (7,102 m) in the Ganesh Himal massif. Sympathoadrenal activity was evaluated by measuring urinary excretion of adrenaline, noradrenaline, metanephrines, and vanillinmandelic acid. Adrenocortical function was assessed by measuring urinary excretion of free cortisol, 17 OHCS (17-hydroxycorticosteroids) and androgenic status by measuring testosterone glucuronide, Adiol (5 alpha-androstane-3 alpha, 17 beta diol) and 17KS (17-ketosteroids). Reference values were obtained at Chamonix at 1,037 m during rest. During trekking noradrenaline increased significantly while Adiol and 17-KS decreased. The fall in the urinary androgenic pool persisted during the next phases of the expedition. At base camp (4,800 m) noradrenaline, its metabolites and free cortisol increased mainly during physical activity. Above 6,000 m, adrenaline, noradrenaline, their metabolites, free cortisol and 17-OHCS reached a maximum value. During the return to sea level, the urinary level of these parameters was still high. The drop in the urinary androgenic pool observed during trekking and exposure to high altitude confirms results obtained in other studies on prolonged efforts. This hypoandrogenicity may play an important role in the metabolic adaptations as well as in the mental state of the climbers. The increase of sympathoadrenal activity and of adrenocortical function may be considered as a regulatory element in the adaptative response to hypoxia and other stressors proper to high altitude.