Abstract
The cardiovascular responses of the fetus to hypoxemia are characterized by hypertension and bradycardia and are mediated by increases in sympathetic and parasympathetic tone. The sympathetic activity is likely to be a combination of increased adrenergic neuronal tone and circulating Cat. This study was undertaken to quantitate plasma norepinephrine (NE) and epinephrine (E) levels at rest and following hypoxemia in 10 chronically catheterized fetal lambs in utero. Hypoxemia was produced by gradual inflation of an umbilical cord cuff-constrictor while fetal heart rate and blood pressure were monitored continuously. Cat were measured by radioenzymatic assay using 50 μL of plasma.
Control E levels rose significantly during the last .25 gestation from 16±6 to 37±7 pg/ml (p<.05). NE and E increased exponentially in response to hypoxemia and the magnitude of the response was independent of gestational age. In conclusion, the late gestation fetal lamb is capable of manifesting a profound Cat response to hypoxemia. The increase in plasma NE and E appears to play a major role in the fetal cardiovascular compensation to stress.
Log in or create a free account to read this content
Gain free access to this article, as well as selected content from this journal and more on nature.com
or
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Lewis, A., Evans, W. & Sischo, W. 265 FETAL CATECHOLAMINE (CAT) RESPONSE TO HYPOXEMTA. Pediatr Res 15 (Suppl 4), 484 (1981). https://doi.org/10.1203/00006450-198104001-00276
Issue date:
DOI: https://doi.org/10.1203/00006450-198104001-00276
