Biomaterial Database

Carotid, not aortic, chemoreceptors mediate the fetal cardiovascular response to acute hypoxemia in lambs. 1993

B Bartelds, and F van Bel, and D F Teitel, and A M Rudolph

Department of Pediatrics, University of California, San Francisco 94143-0544.

The fetal cardiovascular response to acute hypoxemia consists of a decrease in heart rate, a variable change in mean arterial pressure, and an increase in peripheral vascular resistance. This response is mediated by the arterial chemoreceptors. To determine whether chemoreceptors in the carotid artery or in the aorta mediate the fetal cardiovascular response to acute hypoxemia, we studied the response to acute hypoxemia in fetal lambs at 125 to 130 d of gestation after selective carotid (six fetuses) or aortic (five fetuses) denervation. One to 3 d after insertion of catheters, hypoxemia was induced by inflating a balloon occluder around the ewe's hypogastric artery or by giving the ewe 95% N2 and 5% O2 to breathe. The chemoreflex response was measured as decrease in heart rate per decrease in Hb O2 saturation. To validate our results, we also studied the response to chemical stimulation of the chemoreceptors by injection of sodium cyanide into the inferior vena cava. We found that carotid denervation abolished the heart rate and peripheral vascular resistance responses to hypoxemia but that aortic denervation did not. Responses after injection of sodium cyanide were similar to those seen during acute hypoxemia. We conclude that the carotid chemoreceptors, and not the aortic chemoreceptors, mediate the fetal cardiovascular response to acute hypoxemia.

UI	MeSH Term	Description	Entries
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D002319	Cardiovascular System	The HEART and the BLOOD VESSELS by which BLOOD is pumped and circulated through the body.	Circulatory System,Cardiovascular Systems,Circulatory Systems
D002339	Carotid Arteries	Either of the two principal arteries on both sides of the neck that supply blood to the head and neck; each divides into two branches, the internal carotid artery and the external carotid artery.	Arteries, Carotid,Artery, Carotid,Carotid Artery
D002628	Chemoreceptor Cells	Cells specialized to detect chemical substances and relay that information centrally in the nervous system. Chemoreceptor cells may monitor external stimuli, as in TASTE and OLFACTION, or internal stimuli, such as the concentrations of OXYGEN and CARBON DIOXIDE in the blood.	Chemoreceptive Cells,Cell, Chemoreceptive,Cell, Chemoreceptor,Cells, Chemoreceptive,Cells, Chemoreceptor,Chemoreceptive Cell,Chemoreceptor Cell
D003714	Denervation	The resection or removal of the nerve to an organ or part.	Laser Neurectomy,Neurectomy,Peripheral Neurectomy,Radiofrequency Neurotomy,Denervations,Laser Neurectomies,Neurectomies,Neurectomies, Laser,Neurectomies, Peripheral,Neurectomy, Laser,Neurectomy, Peripheral,Neurotomies, Radiofrequency,Neurotomy, Radiofrequency,Peripheral Neurectomies,Radiofrequency Neurotomies
D005260	Female		Females
D005333	Fetus	The unborn young of a viviparous mammal, in the postembryonic period, after the major structures have been outlined. In humans, the unborn young from the end of the eighth week after CONCEPTION until BIRTH, as distinguished from the earlier EMBRYO, MAMMALIAN.	Fetal Structures,Fetal Tissue,Fetuses,Mummified Fetus,Retained Fetus,Fetal Structure,Fetal Tissues,Fetus, Mummified,Fetus, Retained,Structure, Fetal,Structures, Fetal,Tissue, Fetal,Tissues, Fetal
D006439	Hemodynamics	The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.	Hemodynamic
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000860	Hypoxia	Sub-optimal OXYGEN levels in the ambient air of living organisms.	Anoxia,Oxygen Deficiency,Anoxemia,Deficiency, Oxygen,Hypoxemia,Deficiencies, Oxygen,Oxygen Deficiencies