Morris H. Nathanson

The Action of Norepinephrine, Epinephrine and Isopropyl Norepinephrine on the Rhythmic Function of the Heart

The actions of norepinephrine and isopropyl norepinephrine on the rhythmic property of the heart were studied and compared with that of epinephrine. Norepinephrine does not abolish cardiac standstill by carotid sinus stimulation, has no effect on the ventricular rate of heart block and induces a sinus bradycardia. Isopropyl norepinephrine acts similarly to epinephrine in that it abolishes the induced cardiac standstill, increases the ventricular rate of heart block and produces a sinus tachycardia. In the treatment of cardiac arrest, the isopropyl compound appears to possess optimum features as it is very potent in the prevention of cardiac standstill and does not predispose to ventricular fibrillation.

Diffusion of Sulfonamides and Penicillin into Fibrin.

Summary and Conclusion Using a modification of the cup assay method on agar and iibrin plates, there is no evidence of penetration of sulfathiazole and sulfadiazine into fibrin. Penicillin diffuses almost as well into fibrin as into agar. It is suggested that the diffusibility of penicillin into fibrin is an important factor in the efficacy of this substance in the treatment of subacute bacterial endocarditis.

Effect of 1-(3,4, dihydroxyphenyl)-2-Isopropylaminoethanol, (Isopropylepinephrine) on the Rhythmic Property of the Human Heart.

Conclusions Isopropylepinephrine, a non-pressor homologue of epinephrine increases cardiac rhythmicity, as indicated by the abolition of the carotid sinus induced cardiac standstill, and by an increase of the ventricular rate in complete heart block. This drug may be of practical value in the therapy and prevention of sudden cardiac standstill.

STUDIES RELATIVE TO THE CHEMOTHERAPY OF BACTERIAL ENDOCARDITIS

Excerpt The introduction of a successful therapeutic agent in a disease often leads to clarification of the nature of that disease. This is illustrated by the progress that has been made in the elu...

A Method for Study of Circulation Time Throughout the Vascular System.

Summary An objective method is described for the study of circulation time throughout the vascular system. The results of the application of this method in normal subjects and in individuals with peripheral vascular disease is reported.

The cardiovascular effects of paredrine

Abstract Paredrine is the name which has been given to the new epinephrinelike compound, parahydroxyphenylisopropylamine. This substance stands between epinephrine and ephedrine in chemical structure, and, judging from its chemical composition, should possess a more intense sympathomimetic action than ephedrine. The action of this compound in the prevention of cardiac standstill has already been described by one of us (M. H. N.). 1 The purpose of the present communication is to report observations on both the cardiac and pressor actions of the substance, and to discuss therapeutic applications.

Comparative Pressor Effects of Parahydroxyphenylisopropylamine (Paredrine) and Parahydroxyphenylisopropylmethylamine (Paredrinol)

Conclusions Paredrine and paredrinol have a definite pressor effect in man when administered orally or subcutaneously. The systolic pressure is much more influenced than the diastolic pressure. Paredrine consistently shows a much greater and more prolonged pressor action than paredrinol. There is a marked variation in response in different individuals to a given dose. A comparison of the results of oral and subcutaneous administration in the same individual indicates in most instances a complete or practically complete absorption and utilization of these compounds when administered by mouth.

Effect of Paredrine on Blood Specific Gravity and Blood Volume

Conclusion The administration of paredrine in doses sufficient to produce a definite and prolonged rise in blood pressure has no influence on the specific gravity of the blood and blood volume in normal individuals.