Power spectral analysis of the baroreflex in neonatal swine.
The baroreflex was observed in neonatal swine as young as 4 h of age. Bolus injections of Na nitroprusside (NP) and phenylephrine (PE), induced changes in blood pressure and elicited changes in both heart rate and in cervical sympathetic and splanchnic discharge; changes in sympathetic discharge were reflected in altered power spectral magnitude. Measures of heart rate showed that the magnitude of the PE-induced decreases was positively correlated with increasing postnatal age. The results indicate that the baroreflex, as indicated by changes in sympathetic discharge and heart rate, is present in early neonatal swine.
Department of Physiology, State University of New York, Brooklyn 11203.
H L
HL
Cohen
P M
PM
Gootman
B W
BW
Hundley
G
G
Condemi
L P
LP
Eberle
D000375:Aging / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D001794:Blood Pressure / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D009333:Neck / Q000294:innervation; D009599:Nitroprusside / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D011311:Pressoreceptors / Q000502:physiology*; D012018:Reflex / Q000502:physiology*; D013153:Splanchnic Nerves / Q000502:physiology; D013552:Swine; D013564:Sympathetic Nervous System / Q000502:physiology
D009599:Nitroprusside; D010656:Phenylephrine