Journal of Applied Physiology, Vol 69, Issue 1 201-206, Copyright © 1990 by American Physiological Society

ARTICLES

Systemic vascular reactivity during high-altitude pregnancy

G. L. Harrison and L. G. Moore
Cardiovascular Pulmonary Research Laboratory, University of Colorado Health Sciences Center, Denver 80262.

There is an increased incidence of preeclampsia at high compared with low altitude. Increased vasoreactivity, possibly due to a deficiency of vasodilator prostaglandins, is thought to contribute to the etiology of preeclampsia. We sought to determine whether high-altitude exposure increased systemic vascular reactivity during pregnancy. We measured systemic vascular reactivity and contractile sensitivity of isolated aortic rings from pregnant and nonpregnant guinea pigs kept for 6 wk at either simulated high altitude (3,900 m) or low altitude (1,600 m). We found that pregnancy at high compared with low altitude increased baseline systemic vascular resistance (SVR) but not the SVR response to angiotensin II in awake unstressed guinea pigs. Contractile sensitivity to norepinephrine was also increased in aortic rings isolated from high-altitude compared with low-altitude pregnant animals. Meclofenamate, a prostaglandin synthesis inhibitor, did not equalize vasoreactivity in the high- and low-altitude pregnant guinea pigs or in their isolated aortic rings. We concluded that pregnancy at high compared with low altitude increased base-line SVR and aortic contractile sensitivity but that mechanisms other than decreased vasodilator prostaglandin production were responsible.

This article has been cited by other articles:

				S. N. Mateev, R. Mouser, D. A. Young, R. P. Mecham, and L. G. Moore Chronic hypoxia augments uterine artery distensibility and alters the circumferential wall stress-strain relationship during pregnancy J Appl Physiol, June 1, 2006; 100(6): 1842 - 1850. [Abstract] [Full Text] [PDF]

				M. M. White, R. E. McCullough, R. Dyckes, A. D. Robertson, and L. G. Moore Chronic hypoxia, pregnancy, and endothelium-mediated relaxation in guinea pig uterine and thoracic arteries Am J Physiol Heart Circ Physiol, June 1, 2000; 278(6): H2069 - H2075. [Abstract] [Full Text] [PDF]

				M. M. White, R. E. McCullough, R. Dyckes, A. D. Robertson, and L. G. Moore Effects of pregnancy and chronic hypoxia on contractile responsiveness to alpha 1-adrenergic stimulation J Appl Physiol, December 1, 1998; 85(6): 2322 - 2329. [Abstract] [Full Text] [PDF]

				C. De Angelis and G. T. Haupert Jr. Hypoxia triggers release of an endogenous inhibitor of Na+-K+-ATPase from midbrain and adrenal Am J Physiol Renal Physiol, January 1, 1998; 274(1): F182 - F188. [Abstract] [Full Text] [PDF]

				S. Zamudio, K. K. Leslie, M. White, D. D. Hagerman, and L. G. Moore Low Serum Estradiol and High Serum Progesterone Concentrations Characterize Hypertensive Pregnancies at High Altitude Reproductive Sciences, July 1, 1994; 1(3): 197 - 205. [Abstract] [PDF]