[Heart volume overload in the rabbit during growth via chronic arteriovenous fistula. Evaluation of an original model]. / Surcharge volumétrique cardiaque chez le lapin en croissance par fistule artério-veineuse chronique. Evaluation d'un modèle original.

A heart volume overload model was developed in male New Zealand rabbit nine weeks old, using femorofemoral or jugulo-carotid fistulae, producing 50% increase of the mean cardiac output. An evaluation was performed after 2 and 11 weeks. It was evaluated by dimensional echocardiogram and doppler system flow measurement at the aorta ring, angiography and right cardiac pressure recording. This hemodynamic analysis was completed by a heart and fistulae histopathological study. In some volume overload cases, an increasing volume index parameter was described. Two weeks later an increase of the cardiac frequency and a dilatation of the aorta ring were observed but the stroke volume remained unchanged. 11 old weeks fistula animals presented similar frequency and stroke volume. So, the heart compensatory mechanisms varied with the age of the rabbit. The right catheter and cardiac angiography were not useful for ventricular volume overload estimation. Histopathological study showed parenchymal changes and alveolo capillary congestion. An increase of the heart weight/body weight ratio was described. When analysed by ultrasound and blood flow measurement, data were similar to those obtained by invasive pressure recordings or by dilution system. An experimental model of overload volume in rabbit with non invasive recording methods (bidimensional ultrasound and doppler system) can be proposed.

[Consequences of ischemia of the terminal ileum in the rat: influence of exclusive parenteral nutrition]. / Conséquences de l'ischémie de l'ileon terminal chez le rat: influence de la nutrition parentérale exclusive.

An experimental model of ischemia of the distal part of the small intestine has been realized in rats. This experimental study realizes a moderate ischemia of the distal part of ileum loops, by vascular ligations. An important decreasing of the intestinal motility is observed 2 days after the operation, by in vitro study. The motility became normal 7 days after. During this time a microbiological evaluation revealed an important increasing of anaerobic germ in the distal ileum. Total parenteral nutrition preserves the intestinal motility and the endoluminal flora. Ischemia of the small bowel is an important component of enterocolitis by modification of the peristalsis. The total Parenteral Nutrition in such condition seems to protect the intestinal flora.

[Dopplerography of the venous return of the foot in the healthy subject. Preliminary to a study of ambulation]. / Dopplérographie du retour veineux du pied chez le sujet normal. Préliminaire à une étude de la marche.

The direction of venous return was monitored continuously by the Doppler method at 4 MHz, in order to study the effects of posture and certain kinesitherapeutic maneuvers on venous return in the foot of young, healthy and trained adults (kinesitherapy monitors, yoga assistants). It was noted that: the acceleration of venous return in the foot was expiratory in the recumbent position and inspiratory in the standing position; dorsiflexion (leg on foot or toes on heel) caused a more pronounced spurt phenomenon than plantar flexion; massage repeated at high frequency is less beneficial for venous return than slower massage, which allows better adaptation of venous compliance.

Sweat collection from athletes.

The difficulty in taking sweat during heavy physical exercise has drawn the authors into testing a technique of sampling generally used in paediatrics. The fact that the results, which have been dealt with statistically, should coincide with the physiological facts already published allows us to consider a use of the technique in order to investigate the physiological mechanisms in action during sweating under different metabolic conditions.

[Control of hypertension and blood lactate during exercise. Comparison of central antihypertensive agents with the cardio-selective beta blockers metoprolol and atenolol]. / Contrôle de l'hypertension artérielle et lactatémie à l'effort. Comparaison des antihypertenseurs centraux avec les bêtabloquants cardio-sélectifs métoprolol et aténolol.

To assess whether betablockers (BB) would better control blood pressure than central antihypertensive drugs (CAD) clonidine or alpha methyldopa in hypertensive patients during exercise, comparable triangular ergometric bicycle exercises were performed by the same patients while their hypertension had been controlled at rest either with CAD or BB. Blood pressure, heart rate and blood lactate before and during exercise were compared in II patients treated with metoprolol and CAD, and in 12 other patients treated with atenolol and CAD. Systolic and diastolic blood pressure on exercise were significantly lower with BB than with CAD. Heart rate and rate-pressure product were always lower with BB than with CAD. Blood lactate increase was greater with BB than with CAD. The work capacity was greater with atenolol than with CAD, but comparable between metoprolol and CAD.

[Application of the Doppler examination to the study of changes in the venous circulation of muscles during exercise]. / Application de la dopplerographie a l'étude des modifications de la circulation veineuse du muscle en exercice.

The authors use Doppler examination to study the functional hyperaemia of healthy muscle during muscle contraction. In the leg, isometric contraction of the gastrocnemii produces: 1) a flush effect, rapid but transient (1 to 2 sec.); 2) next a speed intermediate between that at peak and that at rest; 3) finally, a post-contractile hyperaemia. In the case of isotonic contractions, the same type of tracing is oberved more clearly for dorsal flexion of the foot (dorsiflexion) than for plantar flexion (extesion), and this occurs whether the mode of movement is active or passive. In the normal untrained subject, fatigue due to repetition of movement occurs very quickly, whatever the conditions, and results in a diminution of the venous flush. But in the trained subject, this effect does not appear, or not till much later.

[Metabolic and pharmacologic interactions on the bronchial tonus]. / Interactions métaboliques et pharmacologiques sur le tonus bronchique.

After reminding data concerning the part played by the as a rule antagonist cAMP system in moticity of the smooth muscle fibers in general and of the bronchial fibers in particular, the authors study the different types of interaction on bronchial muscular fibers which have been discribed. It is concerning the adrenergic fibers that the experimental and clinical data are prevalent (role of bronchial alpha- and beta2- receptors) and the authors point especially to their own studies performed since 1964 concerning the alpha1- -bronchoconstrictive component and progressive auto-inhibition of the bronchial beta2- receptors. But autacoids (serotonin, bradykinin, histamine and prostaglandines) and with the stimulating or inhibiting agents of the beta2 -receptors also begin to be recognized.

[Bronchial mediators and receptors: current data]. / Médiateurs et récepteurs bronchiques: données actuelles

This is a very precise study of the mechanisms which intervene in bronchial motility. It is apparent that the most important recent acquisitions in the realm of bronchial mediators, over these last 10 years remains: the demonstration in the animal and in man of the duality between adrenergic bronchoconstriction of alpha nature and adrenergic bronchoconstriction of beta-2 nature, the duality of the effects of prostaglandins (PGF2 alpha broncho-constrictive, and PGE2 bronchodilator), and the role of cyclic AMP at the junction of the action of numerous substances which are active on the bronchial musculature.