|
|
||||||||
1 Center for Perinatal Biology, Department of Pharmacology and Physiology, Loma Linda University School of Medicine, Loma Linda, California 92350; and 2 Jiangxi Provincial Key Laboratory for Animal Biotechnology, Jiangxi Agricultural University, Nanchang, Jiangxi, China 330045
During pregnancy, maternal plasma
cortisol concentrations approximately double. Given that cortisol plays
an important role in the regulation of vascular reactivity, the present
study investigated the potential role of cortisol in potentiation of
uterine artery (UA) contractility and tested the hypothesis that
pregnancy downregulated the cortisol-mediated potentiation. In vitro
cortisol treatment (3, 10, or 30 ng/ml for 24 h) produced a
dose-dependent increase in norepinephrine (NE)-induced contractions in
both nonpregnant and pregnant (138-143 days gestation) sheep UA.
However, this cortisol-mediated response was significantly attenuated
by ~50% in pregnant UA. The 11
-hydroxysteroid dehydrogenase
(11-
HSD) inhibitor carbenoxolone did not change the effect of
cortisol in nonpregnant UA but abolished its effect in pregnant UA by
increasing the NE pD2 in control tissues from 6.20 ± 0.05 to 6.59 ± 0.11. The apparent dissociation constant value of
NE
1-adrenoceptors was not changed by cortisol in
pregnant UA but was decreased in nonpregnant UA. There was no
difference in glucocorticoid receptor density between nonpregnant and
pregnant UA. Cortisol significantly decreased endothelial nitric oxide
(NO) synthase protein levels and NO release in both nonpregnant and
pregnant UA, but the effect of cortisol was attenuated in pregnant UA
by ~50%. Carbenoxolone alone had no effects on NO release in
nonpregnant UA but was decreased in pregnant UA. These results suggest
that cortisol potentiates NE-mediated contractions by decreasing NO
release and increasing NE-binding affinity to
1-adrenoceptors in nonpregnant UA. Pregnancy attenuates
UA sensitivity to cortisol, which may be mediated by increasing type-2
11-
HSD activity in UA.
nitric oxide;
1-adrenoceptor; 11-
HSD; glucocorticoid receptor
This article has been cited by other articles:
![]() |
A. E. Michael and A. T. Papageorghiou Potential significance of physiological and pharmacological glucocorticoids in early pregnancy Hum. Reprod. Update, September 1, 2008; 14(5): 497 - 517. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Chang and Lubo Zhang Review Article: Steroid Hormones and Uterine Vascular Adaptation to Pregnancy Reproductive Sciences, April 1, 2008; 15(4): 336 - 348. [Abstract] [PDF] |
||||
![]() |
F. Li, C. E. Wood, and M. Keller-Wood Adrenalectomy alters regulation of blood pressure and endothelial nitric oxide synthase in sheep: modulation by estradiol Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2007; 293(1): R257 - R266. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Zhang, D. Xiao, L. D. Longo, and L. Zhang Regulation of {alpha}1-adrenoceptor-mediated contractions of uterine arteries by PKC: effect of pregnancy Am J Physiol Heart Circ Physiol, November 1, 2006; 291(5): H2282 - H2289. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Horvath and A. Wanner Inhaled corticosteroids: effects on the airway vasculature in bronchial asthma Eur. Respir. J., January 1, 2006; 27(1): 172 - 187. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Xiao and L. Zhang Adaptation of uterine artery thick- and thin-filament regulatory pathways to pregnancy Am J Physiol Heart Circ Physiol, January 1, 2005; 288(1): H142 - H148. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Xiao, X. Huang, S. Bae, C. A. Ducsay, L. D. Longo, and L. Zhang Cortisol-mediated regulation of uterine artery contractility: effect of chronic hypoxia Am J Physiol Heart Circ Physiol, February 1, 2004; 286(2): H716 - H722. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Xiao, X. Huang, W. J. Pearce, L. D. Longo, and L. Zhang Effect of cortisol on norepinephrine-mediated contractions in ovine uterine arteries Am J Physiol Heart Circ Physiol, April 1, 2003; 284(4): H1142 - H1151. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |