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A comparative study of ephedrine, tyramine and epinephrine with special reference to the circulation
Chen, H. K., and Meek, Walter J.: A Comparative Study of Ephedrine, Tyramine .Tour. Pharmaeol. and Epinephrine with Special Reference to the Circulation. and
Espcr.
Thcrap.,
192G,
SST-iii,
59.
Buitablc doses of cphedrinc make the blood l~r~3sure rise to almost the b:CrIIc I(~\<~1 as ordinary doses of epincphrine given to laboratory itninmls and maintain it for :I much longer time. SVhcn miscd with cpinephrin,, cphcdrine shows s.vncrgisul ullt only in intensit.y but in duration. Tyrarnine coniparcd with cphcdrine raises blo~nl l~rc3:“ure ILiglwr but does nut maiw On ret.ain a high level as long when injeetcd intravenously in anesthctizcd dogs. of 16 to ?ll peated injections in stimulating doses tymmine, when given at intervals minutes, does not rapidly low its effectiveness in raising the blood pr~ssura as tyraminc shows synergisnr with ephinephrine both ephedrine does. Like ephedrine, in intensity and duration. In man, w11ei1 give by mouth, tymmiuc fails to raise blood pressure while ephedrine dew. Tyramine, when injected intravenously in ancsthetixrd dogs increases the heart rate and amplitude of contractions if the vapi are atrophinized during the rise of blood pressure. Under the same conditions it incxeascs the cardiac minute output as confirmed by eardiometric and teleroent~-cno~raplli(: nlcthods. Large doses 0-F tyramine also produce a sudden fall of blood pressure, but this fall, unlike rphedrinc. is not due to the interference of the automatic or conductive system of the heart. as shown hy the clcctrorardioaram. but slur to vase dilatation.
The authors explain the difference of the chemical stability and pcrsistcnce of action between tyramine and elGnephrinc on the one hand and ephedrine on the other chiefly in the phenolic hydrusyl k‘groups of the thrrs substances. The absence of thi+ group from ephedrine should lueke it more rcsistclnt to phy.iic*al and chemical agents as well as other gastrointestinal enzymes. Persistenw of action confcrrcd by cph~ ~lrinn is an important tlrwa~lcutic a
Harrison.
Dog.
Tinsley R., and Jour. Clin. Invest.,
Blalock, Alfred: 19-Oiit ii, 13.5.
Cardiac
Output
in
Pneumonia
in the
The accidental finding of hish cardiac output in a supposedly normal dog, whicll at autopsy was found to hare c+&ensi\-c l)roncllol~~lc~~nlonia, lead the authors to study the hlood flow on twenty-fuur a~lditional animals. Thc;v have studied the various factors causing variations in the output or the hrart in pneumonia. The cardiac nutput was s;tnclicrl l,- thr Fick mctlin~l. Thy -fnun(l thr wtpnt to 11c usuallyil:cwawrl. Whrn thn infection is of short
Espcr.
Thcrap.,
192G,
SST-iii,
59.
Buitablc doses of cphedrinc make the blood l~r~3sure rise to almost the b:CrIIc I(~\<~1 as ordinary doses of epincphrine given to laboratory itninmls and maintain it for :I much longer time. SVhcn miscd with cpinephrin,, cphcdrine shows s.vncrgisul ullt only in intensit.y but in duration. Tyrarnine coniparcd with cphcdrine raises blo~nl l~rc3:“ure ILiglwr but does nut maiw On ret.ain a high level as long when injeetcd intravenously in anesthctizcd dogs. of 16 to ?ll peated injections in stimulating doses tymmine, when given at intervals minutes, does not rapidly low its effectiveness in raising the blood pr~ssura as tyraminc shows synergisnr with ephinephrine both ephedrine does. Like ephedrine, in intensity and duration. In man, w11ei1 give by mouth, tymmiuc fails to raise blood pressure while ephedrine dew. Tyramine, when injected intravenously in ancsthetixrd dogs increases the heart rate and amplitude of contractions if the vapi are atrophinized during the rise of blood pressure. Under the same conditions it incxeascs the cardiac minute output as confirmed by eardiometric and teleroent~-cno~raplli(: nlcthods. Large doses 0-F tyramine also produce a sudden fall of blood pressure, but this fall, unlike rphedrinc. is not due to the interference of the automatic or conductive system of the heart. as shown hy the clcctrorardioaram. but slur to vase dilatation.
The authors explain the difference of the chemical stability and pcrsistcnce of action between tyramine and elGnephrinc on the one hand and ephedrine on the other chiefly in the phenolic hydrusyl k‘groups of the thrrs substances. The absence of thi+ group from ephedrine should lueke it more rcsistclnt to phy.iic*al and chemical agents as well as other gastrointestinal enzymes. Persistenw of action confcrrcd by cph~ ~lrinn is an important tlrwa~lcutic a
Harrison.
Dog.
Tinsley R., and Jour. Clin. Invest.,
Blalock, Alfred: 19-Oiit ii, 13.5.
Cardiac
Output
in
Pneumonia
in the
The accidental finding of hish cardiac output in a supposedly normal dog, whicll at autopsy was found to hare c+&ensi\-c l)roncllol~~lc~~nlonia, lead the authors to study the hlood flow on twenty-fuur a~lditional animals. Thc;v have studied the various factors causing variations in the output or the hrart in pneumonia. The cardiac nutput was s;tnclicrl l,- thr Fick mctlin~l. Thy -fnun(l thr wtpnt to 11c usuallyil:cwawrl. Whrn thn infection is of short