© 2004 by European Society of Cardiology
Copyright © 2004, European Society of Cardiology
Long-term effects of repeated pregnancies (multiparity) on blood pressure regulation
Department of Physiology, University of Alberta, Edmonton, Alberta Canada, T6G 2S2
* Corresponding author. 475 Heritage Medical Research Centre, University of Alberta, Edmonton, Alberta Canada, T6G 2S2. Tel.: +1 780 492 6612; fax: +1 780 492 7752. E-mail address: susan.jacobs{at}ualberta.ca
Objective: Pregnancy is associated with profound alterations in the cardiovascular system, the long-term effects of which are unknown. Human epidemiological studies suggest that multiparity (multiple pregnancies) increases the risk of cardiovascular disease. The mechanisms underlying these findings remain to be elucidated. The objective of this study was to determine the long-term effects of parity on cardiovascular regulation. Methods: Pressor responses to phenylephrine (PE) and acute stress were compared in conscious age-matched repeatedly breed (RB) and virgin rats. Vascular compliance and reactivity of isolated resistance-sized mesenteric arteries were studies using pressure and wire myograph. Results: We found that both exogenous PE and acute stress elicited greater pressor responses in RB than in aged-matched virgins. Pressure and wire myography also revealed that small mesenteric arteries from RB rats were less compliant than those from virgins (RB: 0.24±0.04 µm mm Hg–1, n=6 vs. virgins: 0.63±0.06 µm mm Hg–1, n=6; p
0.05) and were more sensitive to PE (EC50 RB: 1.58±0.08x10–6 M, n=10 vs. virgins: 2.05±0.09x10–6 M, n=14; p0.05). Removal of the endothelium abolished the difference in sensitivity. More specifically, the augmented vascular response of RB was both nitric oxide (NO) and cyclooxygenase dependent. By contrast, there was no difference in methacholine-induced vasodilation of phenylephrine-preconstricted vessels. Conclusion: Our results suggest that repeated pregnancies induce long-term alterations in cardiovascular regulation due to changes in vascular compliance and endothelium-dependent vasoconstriction. We propose that such changes might influence the risk for cardiovascular disease in multiparous women.
KEYWORDS Parity; Stress; Cardiovascular diseases; Vascular reactivity
1 Current address: University of Sheffield, Division of Clinical Sciences (South), Section of Surgical and Anaesthetic Sciences, Academic Anaesthesia Unit, K Floor, Royal Hallamshire Hospital, Sheffield S10 2JF, UK.
Time for primary review 32 days
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  H. E. Tawfik, J. Cena, R. Schulz, and S. Kaufman Role of oxidative stress in multiparity-induced endothelial dysfunction Am J Physiol Heart Circ Physiol, October 1, 2008; 295(4): H1736 - H1742. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. Dhawan, Z. L. S. Brookes, and S. Kaufman Repeated pregnancies (multiparity) increases venous tone and reduces compliance Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2005; 289(1): R23 - R28. [Abstract] [Full Text] [PDF]
|
|