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Assessment of Maternal Vascular Remodeling During Pregnancy in the Mouse Uterus
Published on: December 5, 2015
Pregnancy and estradiol decrease GTPase activity in the guinea pig uterine artery
I A Buhimschi1, G Hall, L P Thompson
1Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201-1559, USA.
American Journal of Physiology. Heart and Circulatory Physiology
|October 23, 2001
Summary
Pregnancy and estradiol reduce GTPase activity in uterine arteries, enhancing cGMP release. This G protein signaling change may explain cardiovascular adaptations during pregnancy.
Area of Science:
- Cardiovascular Physiology
- Endocrinology
- Molecular Signaling
Background:
- Pregnancy significantly alters cardiovascular function, redistributing cardiac output.
- The underlying molecular mechanisms, particularly estrogen's role in G protein signaling, are not fully understood.
Purpose of the Study:
- To investigate the impact of pregnancy and estrogen on G protein-mediated signal transduction in guinea pig arteries.
- To determine if altered signaling in uterine arteries contributes to pregnancy-induced cardiovascular changes.
Main Methods:
- Assayed high-affinity GTPase activity in aortas, uterine arteries (UAs), and mesenteric arteries (MAs) from pregnant, nonpregnant, and ovariectomized guinea pigs.
- Measured cyclic guanosine monophosphate (cGMP) generation in response to acetylcholine (ACh) with or without cholera toxin (CTX).
Main Results:
- Pregnancy decreased GTPase activity in UAs but not in aortas or MAs.
- 17beta-estradiol treatment reduced UA GTPase activity.
- ACh increased cGMP in pregnant UAs; CTX mimicked this effect in nonpregnant UAs, indicating reduced GTPase activity of a CTX-sensitive G protein.
Conclusions:
- Pregnancy and estradiol decrease GTPase activity of a CTX-sensitive G protein in uterine arteries.
- This alteration enhances receptor-mediated cGMP release, potentially contributing to cardiovascular adaptations during pregnancy.
