Effect of alpha-adrenergic agonist and antagonist infusion on the umbilical and uterine circulations of pregnant sheep

Biology of the Neonate
G K OakesR A Chez

Abstract

The effects of the alpha-adrenergic agonists, norepinephrine and methoxamine, and the alpha-antagonist, phenoxybenzamine, on umbilical and uterine blood flows, fetal and maternal heart rates, arterial and venous pressures were examined in near-term chronic sheep preparations. Norepinephrine injection or methoxamine infusion to either fetus or ewe resulted n a respective unilateral fetal or maternal pressur response associated with bradycardial. Uterine blood flow decreased significantly with alpha-agonist administration to either fetus or ewe. Umbilical blood flow did not change with either, but an increase in calculated umbilicalo vascular resistance did occur after fetal administrations of the alpha-agonist. Thus, both the uterine and umbilical vascular beds are responsive to alpha-agonism, but maternal uteroplacental perfusion appears to be more sensitive. alpha-Blockade in either fetus or mother produced no significant changes in umbilical or uterine blood flows or fetal or maternal perfusion pressure suggesting that basal alpha-adrenergic tone is unnecessary for normal maintenance of either fetal or maternal uteroplacental circulation.

Citations

May 2, 1991·European Journal of Pharmacology·L Zhang, D C Dyer
Oct 1, 1995·European Journal of Obstetrics, Gynecology, and Reproductive Biology·J Räsänen, P Jouppila
Apr 6, 2002·Reproductive Toxicology·Sonia A Tabacova, Carole A Kimmel
Oct 17, 1998·British Journal of Pharmacology·L ZhangL D Longo
Aug 1, 1991·American Journal of Obstetrics and Gynecology·H van HuisselingT H Hasaart
Feb 1, 1993·International Journal of Gynaecology and Obstetrics : the Official Organ of the International Federation of Gynaecology and Obstetrics·I YolesJ Ovadia
Jun 26, 1998·Journal of Cardiovascular Pharmacology·A T OmoniyiH H Szeto

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.