(Hypertension. 1997;30:596.)
© 1997 American Heart Association, Inc.
Articles |
Possible Involvement of Endothelium-Derived Hyperpolarizing Factor in Vascular Responses of Abdominal Aorta From Pregnant Rats
From the Departamento de Fisiología y Farmacología (R.A.B., E.C.H.), Sección de Graduados (C.C.H.), Escuela Superior de Medicina del IPN, Plan de San Luis y Díaz Mirón, Casco de Santo Tomás; and the Departamento de Farmacología (B.E.) and the Sección de Terapéutica Experimental (E.H.), CINVESTAV IPN, Mexico.
Correspondence to Rosa A. Bobadilla, MD, Dept de Fisiología y Farmacología, Escuela Superior de Medicina del IPN, Plan de San Luis y Díaz Mirón, Casco de Santo Tomás, Mexico DF, CP 11340.
Abstract Increased relaxant response to acetylcholine during pregnancy is proposed to be due to an estrogen-mediated increase in nitric oxide release. We studied acetylcholine-induced pathways of relaxation in the thoracic and abdominal aortic rings from pregnant and nonpregnant Wistar-Kyoto rats and measured basal and stimulated release of nitrites in these vessels. Endothelium-dependent relaxation was significantly greater in pregnant than in nonpregnant rats. Acetylcholine provoked a concentration-dependent relaxation on thoracic and abdominal aortic rings from nonpregnant and pregnant rats. After N118-nitro-L-arginine methyl ester pretreatment, the relaxation was significantly inhibited in the two preparations of nonpregnant and pregnant rodents. The relaxation was not inhibited by indomethacin in any of the aortic segments from pregnant and nonpregnant rats. After cytochrome P450 arachidonic acid metabolism inhibitor clotrimazole, a nonsignificant decrease in the Emax to acetylcholine-induced relaxation was observed in the thoracic segments of pregnant and nonpregnant rats. On the other hand, in abdominal aorta, clotrimazole decreased maximal relaxation in rings from pregnant rats (P<.05) but did not change the acetylcholine-induced relaxation from nonpregnant rats. Our results show an increase in the acetylcholine-stimulated release of nitrites in thoracic aortic rings from pregnant rats compared with rings from nonpregnant rats, which cannot be evidenced in abdominal aortic rings. These results suggest that acetylcholine-induced vasodilation in the abdominal segment from pregnant rats is mediated only in part by nitric oxide, the remainder apparently due to an endothelium-derived vasodilator, cytochrome P450-dependent, which may be endothelium-derived hyperpolarizing factor/epoxyeicosatrienoic acid.
Key Words: pregnancy • rats • aorta • nitric oxide • endothelium-derived factors
This article has been cited by other articles:
 |
|
 |
|
  K. A. Hagedorn, C.-L. Cooke, J. R. Falck, B. F. Mitchell, and S. T. Davidge Regulation of Vascular Tone During Pregnancy: A Novel Role for the Pregnane X Receptor Hypertension, February 1, 2007; 49(2): 328 - 333. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Meziani, B. Van Overloop, F. Schneider, and A. Gairard Parathyroid Hormone-Related Protein-induced Relaxation of Rat Uterine Arteries: Influence of the Endothelium During Gestation Reproductive Sciences, January 1, 2005; 12(1): 14 - 19. [Abstract] [PDF]
|
|
|
|
 |
|
 L. Brawley, C. Torrens, F. W. Anthony, S. Itoh, T. Wheeler, A. A. Jackson, G. F. Clough, L. Poston, and M. A. Hanson Glycine rectifies vascular dysfunction induced by dietary protein imbalance during pregnancy J. Physiol., January 15, 2004; 554(2): 497 - 504. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Mateev, A. H. Sillau, R. Mouser, R. E. McCullough, M. M. White, D. A. Young, and L. G. Moore Chronic hypoxia opposes pregnancy-induced increase in uterine artery vasodilator response to flow Am J Physiol Heart Circ Physiol, March 1, 2003; 284(3): H820 - H829. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Martinez-Orgado, R. Gonzalez, S. Tovar, J. Marin, M. Salaices, and M. J. Alonso Administration of N{omega}-L-Arginine Methyl Ester (L-NAME) Impairs Endothelium-Dependent Relaxation in Gravid But Not Nongravid Rats Reproductive Sciences, February 1, 2003; 10(2): 74 - 81. [Abstract] [PDF]
|
|
|
|
|
|
S. Veerareddy, C.-L. M. Cooke, P. N. Baker, and S. T. Davidge Vascular adaptations to pregnancy in mice: effects on myogenic tone Am J Physiol Heart Circ Physiol, December 1, 2002; 283(6): H2226 - H2233. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. L. Xu, R. A. Santizo, H. M. Koenig, and D. A. Pelligrino Chronic estrogen depletion alters adenosine diphosphate-induced pial arteriolar dilation in female rats Am J Physiol Heart Circ Physiol, November 1, 2001; 281(5): H2105 - H2112. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J.J.D. Lucca, A.S.O. Adeagbo, and N.L. Alsip Oestrous cycle and pregnancy alter the reactivity of the rat uterine vasculature Hum. Reprod., December 1, 2000; 15(12): 2496 - 2503. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. T. Littleton-Kearney, D. M. Agnew, R. J. Traystman, and P. D. Hurn Effects of estrogen on cerebral blood flow and pial microvasculature in rabbits Am J Physiol Heart Circ Physiol, September 1, 2000; 279(3): H1208 - H1214. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J.J.D. Lucca, A.S.O. Adeagbo, and N.L. Alsip Influence of oestrous cycle and pregnancy on the reactivity of the rat mesenteric vascular bed Hum. Reprod., April 1, 2000; 15(4): 961 - 968. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. H. Capdevila, J. R. Falck, and R. C. Harris Cytochrome P450 and arachidonic acid bioactivation: molecular and functional properties of the arachidonate monooxygenase J. Lipid Res., February 1, 2000; 41(2): 163 - 181. [Abstract] [Full Text]
|
|
|
|
|
|
M. F. V. Dantas, M. Urban, D. Spray, M. H. Catelli de Carvalho, and R. d. C. A. T. Passaglia Increased Acetylcholine-Induced Vasodilation in Pregnant Rats : A Role for Gap Junctional Communication Hypertension, October 1, 1999; 34(4): 937 - 942. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Shern-Brewer, N. Santanam, C. Wetzstein, J. White-Welkley, and S. Parthasarathy Exercise and Cardiovascular Disease : A New Perspective Arterioscler Thromb Vasc Biol, July 1, 1998; 18(7): 1181 - 1187. [Abstract] [Full Text] [PDF]
|
|