Epinephrine affects hemodynamics of noninnervated normal and all-trans retinoic acid-treated embryonic chick hearts.
OBJECTIVE
To study the acute effect of epinephrine on hemodynamics of noninnervated normal and retinoic-acid-treated embryos.


METHODS
Prospective interventional study design.


METHODS
A total of 190 stage 15 (50-55 h of incubation) chick embryos were randomly treated with 1 microg all-trans retinoic acid and reincubated. At stage 20 (day 3) and stage 24 (day 4), dorsal aortic flow velocities were measured with a 20-MHz pulsed Doppler velocity meter, in normal and retinoic-acid-treated embryos. Flow velocity waveforms were assessed both before and after the administration of epinephrine (5 or 10 microg).


RESULTS
Epinephrine caused a significant increase (p < 0.05) in heart rate, peak and mean velocities, peak acceleration, peak and mean blood flows, stroke volume and dorsal aortic area of both stage 20 and stage 24 normal and retinoic-acid-treated chick embryos. However, before epinephrine administration, stage 24 retinoic-acid-treated embryos displayed a significantly lesser increase in all outcome variables with the exception of dorsal aortic area. This was even observed after epinephrine administration. The effect of retinoic acid on cardiac output could not be compensated by epinephrine application.


CONCLUSIONS
Epinephrine affects hemodynamics in both normal embryos and retinoic-acid-treated embryos prior to sympathetic innervation. A significant difference in hemodynamics exists between stage 24 normal and retinoic-acid-treated embryos. The underlying mechanism for the observed hemodynamic changes will need to be investigated.
Department of Obstetrics and Gynecology, Academic Hospital Rotterdam, Erasmus University, Rotterdam, The Netherlands.
Jeanne Margot
JM
Kroese
Monique L A
ML
Broekhuizen
Rob E
RE
Poelmann
Paul G H
PG
Mulder
Juriy W
JW
Wladimiroff
D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D002642:Chick Embryo; D004837:Epinephrine / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects* / Q000196:embryology / Q000294:innervation / Q000502:physiology*; D006329:Heart Conduction System / Q000196:embryology; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D013318:Stroke Volume / Q000187:drug effects; D013564:Sympathetic Nervous System / Q000196:embryology; D013997:Time Factors; D014212:Tretinoin / Q000494:pharmacology*
D014212:Tretinoin; D004837:Epinephrine