[Limb vasodilation provoked by stimulation of the carotid sinus. Importance of histaminergy in the dog]. / Sur la vasodilatation des membres provoquée par la stimulation du sinus carotidien. Importance de l'histaminergie chez le chien.

The vasodilator reflex induced by baroreceptor stimulation was studied on the hindlimbs of the dog. The reflex was induced by norepinephrine (1 microgram/kg) either by intravenous injection or by direct injection into the carotid sinus. In other experiences, the baroreceptor stimulation was obtained by distension of the sinus by rapid injection of 100 ml of physiological serum. The vascular response was studied by recording the hindlimbs blood flow. One of the limbs was previously pretreated by mepyramine and cimetidine (blockage of histaminergic H1 and H2 receptors). During the first minute after the baroreceptor stimulation, blood samples were collected from the venous blood of hindlimbs for histamine assay (fluorometric assay). Our results show: a much lower vasodilation on the limb pretreated by histamine antagonist, a significant increase during the reflex vasodilation of histamine blood levels measured in the efferent blood of hindlimbs. These results, obtained in experimental conditions as physiological as possible (blood perfusion of the limbs with "natural" hemodynamic parameters) permit to conclude that the vasodilation induced by baroreceptor reflex is at least partially histaminergic in the dog.

Immunoglobulin E in human aqueous humor and corresponding serum. A physiopathological and clinical study.

The analysis of IgE in aqueous humor yielded an average concentration of 3.4 +/- 0.97 U/ml for 22 cataract patients and 5.5 +/- 3.42 U/ml for five uveitis patients. The IgE level in aqueous humor (IgEa.h.) of the cases examined is most probably, beside hematoocular diffusion of serum IgEs, the result of intra-ocular IgE production. In comparison with (mostly normal) IgEs levels, the IgEa.h. concentration appears relatively elevated, not only with uveitis patients, but also with cataract patients, above all when lenticular opacity is accompanied by other ophthalmic diseases (glaucoma, high myopia, diabetes). This "increase" of IgEa.h. concentration in very probably due to the radioimmunosorbent (RIST) technique employed, the most sensitive method available at the time of the present study. Thus, the calculated IgEa.h. value in the cataractous eyes should be regarded simply as approximate to the normal IgEa.h. concentration. These values are of clinical significance however, since a reference IgEa.h. mean-value is indispensable to the interpretation of pathologically high IgEa.h. levels and ethics do not permit of IgEa.h. determination in healthy eyes. The mean IgEa.h. levels of the delayed-type uveitis and cataract patients examined reveal no significant differences. IgEa.h. determination could make a contribution to the etiological clarification of, for example, immediate-type uveitis cases and intra-ocular parasitosis and serve as an appropriate model to study intra-ocular immunomechanisms.

Original method of showing some constitutive elements of the capillary wall.

The ascorbic acid and the 1-epi-3', 4', 5', 5, 7-pentahydroxy-flavan-3-ol have been located in the blood capillary wall by an histochemical method for electron microscopy. The method consists in an intra-arterial administration of vegetal oxydases specific of the compound to put in evidence. Those oxydases fix themselves on their effectors, and the addition of osmium and lead salts gives co-precipitates opaque to electrons.

[Endogenous histamine. Principles of prevention]. / L'histamine endogène. Principes de protection.

After recalling the machanisms of liberation of endogenous histamine and its fate; the author discusses the pharmacological methods of protection of the organism against histamine liberation.

[Study of prostaglandin synthesis during anaphylactic shock in guinea pigs]. / Etude de la synthèse de prostaglandines au cours du choc anaphylactique chez le Cobaye

In guinea pigs actively sensitized with ovalbumin and shocked, we have measured blood histamine and histaminase, pulmonary content in cycli AMP and prostaglandins (PG) E1, E2 and F2alpha. In pulmonary efferent blood, both PGE and PGF are increased. In lung tissue, only PGF2alpha, which are bronchoconstructive mediators, are increased. Th increased level in PG seems to have two origins: first a specific increase, then an increased synthesis secondary to histamine release.

[Study of histamine in asthma]. / Papel de la histamina en el asma

Histamine is generally considered as the principal chemical mediator in experimental allergy of type I and anaphylaxis. However, its part in human bronchial asthma remains discussed, because neither the dosage of histamine in blood, nor the use of antihistaminics have furnished any real evidence. This study is dealing with two elements: the importance of local bronchopulmonary phenomena, and the associated mediators also liberated in asthma, such as SRSA. ECFA, kinines, prostaglandins and disorders of balance between, on one hand, alpha and beta-actions of the catecholamines, and on the other hand, between the two main types of cyclic nucleotides. These considerations should allow a better approach of the asthma etiopathology and perhaps an improvement of its treatment.

[Histamine liberation and its mechanism]. / La libération d'histamine et ses mécanismes

The author, on the basis of his personal work, proposes a classification of the mechanisms of histamine liberation: a metabolic mechanism (acting like anaphylaxis) and a mechanism by amine displacement. Subsequently, the action on histamine of two hydrosoluble vitamins: ascorbic acid and nicotinamide is considered, in the animal as a whole and on the mastocytes of rat peritoneum.