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Biomedical subjects

M Boucher

Publications and source records attributed to M Boucher.

At least 109 records · Page 6Linked to original sources

A comparison of changes in atropine-induced tachycardia and atropine concentration in conscious dogs.

In the conscious dog, after intravenous injection of 0.2 mg/kg 3H-labelled atropine the progressive decrease of the heart rate was well correlated with the disappearance of atropine from the blood. But, with atropine infusion (0.2 mg/kg/h) the tachycardia decreased progressively in spite of an increase in the blood concentration of atropine. Differences appeared between the normal animals or those pretreated with propranolol or reserpine, and the animals which had undergone bilateral thoracic sympathectomy. In the stellectomized animals atropine induced a smaller but much more lasting cardiac acceleration than under the other experimental conditions. It seems that only peripheral factors are involved in the complex interactions between the adrenergic and cholinergic nervous systems at the sinus node level.

Animals↗

Catecholamines and cardiac rhythms in the unanesthetized dog with chronic AV block.

The effects of epinephrine, norepinephrine, and isoproterenol were studied in the nonanesthetized dog with chronic atrioventricular block before and after blockade of cholinergic receptors. Epinephrine and norepinephrine reduced the atrial rate in a reflex manner, whereas isoproterenol increased it. In contrast, all three substances increased idioventricular rate. After atropine, atrial and ventricular rate increases were observed after administration of the three catecholamines. Moreover, blockade of cholinergic receptors led to an increase in ventricular acceleration induced by epinephrine and norepinephrine, but did not significantly modify the acceleration induced by isoproterenol. These results appear to indicate the possibility of the involvement (intensified by a reflex mechanism) of ventricular cholinergic innervation.

Animals↗

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France↗

Comparative effects of amiodarone, perhexiline and bepridil on the cardiac rhythms of the unanesthetized dog in chronic heart block.

The effects of amiodarone, perhexiline and bepridil, which decrease effort cardioacceleration although they have no adrenergic beta blocking properties, were studied in the unanesthetized dog in chronic heart block. All three products decreased atrial rate in a durable way after an initial phase of tachycardia. Amiodarone had no depressant effect on idioventricular rate; however, this was significantly slowed by the other two compounds.

Amines↗

[Study of neurological manifestations of chronic lymphatic leukemia (lymphosis). Role of associated globulin anomalies (apropos of 8 cases)].

The authors emphasize the relative frequency of neurological symptoms in lymphatic leukaemia. Clinically, these cause more or less diffuse encephalitic or multineuritic syndromes, generally a combination of the two. Their pathogenesis is usually connected with lymphoid tissue infiltration into either the meninges or the vascular sheaths of the central nervous system or the sheaths of the roots or of the peripheral nerves. The authors stress the possible function of immunoglobulin abnormalities of the C.S.F. indicative of the presence of the leukaemic process within the nervous system. This pathogenesis prompts the use of therapeutic methods directly attacking leukaemic infiltration of the nervous system (focal cobalt therapy, intrathecal chemotherapy) and the authors have found that these give favourable results.

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