HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 70/6/1886    most recent biolreprod.103.019901v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Gibson, T. C. Articles by Magness, R. R. Search for Related Content PubMed PubMed Citation Articles by Gibson, T. C. Articles by Magness, R. R. Agricola Articles by Gibson, T. C. Articles by Magness, R. R.

Development and Use of an Ovarian Synchronization Model to Study the Effects of Endogenous Estrogen and Nitric Oxide on Uterine Blood Flow During Ovarian Cycles in Sheep¹

Departments of Obstetrics and Gynecology,³ Dairy Science,⁴ Animal Sciences,⁵ Pediatrics,⁶ University of Wisconsin-Madison, Madison, Wisconsin 53706

The objective of the current study was to develop an ovine animal model for consistent study of uterine blood flow (UBF) changes during synchronized ovarian cycles regardless of season. Sheep were surgically bilaterally instrumented with uterine artery blood flow transducers and 5–7 days later implanted with a vaginal progesterone (P₄)-controlled internal drug-releasing device (CIDR; 0.3 g) for 7 days. On Day 6 of P₄, sheep were given two prostaglandin F₂ injections (7.5 mg i.m. 4 h apart). At CIDR removal, Experimental Day 0, zero (n = 9), 500 IU (n = 8), or 1000 IU (n = 7) eCG was injected i.m.; UBF was monitored continuously for 55–75 h. Jugular blood was sampled every 8 h to evaluate levels of P₄, estradiol-17ß (E₂ß) and luteinizing hormone (LH). The inhibitor of nitric oxide synthase, L- nitro-arginine methyl ester (L-NAME) was infused in a stepwise fashion unilaterally into one uterine artery at 48–50 h after 500 IU eCG and the effects on UBF were examined (n = 7). The zero-eCG group gradually increased UBF from a baseline of 17.4 ± 3.9 to 80.5 ± 1.1 ml/min. The 500-IU-eCG group increased UBF between 10 and 15 h from a baseline of 11 ± 3.3 to 83.3 ± 1.0 ml/min, whereas UBF for the 1000-IU-eCG group was higher (100.1 ± 1.7 ml/min) than that seen in either of the other groups. Plasma P₄ fell to baseline within 8 h of CIDR removal, while E₂ß rose gradually in association with elevations in UBF. LH surges occurred between 32 and 56 h after CIDR removal and the LH surge occurred earlier in the 1000-IU-eCG group than the other two groups (P < 0.01). L-NAME infusion dose dependently reduced maximum levels of UBF ipsilaterally by 54.6% ± 6.2%, but contralaterally only by 27.4% ± 8.5%. Regardless of season, either dose of eCG will result in analogous UBF responses. During the follicular phase, elevations in UBF are in part locally controlled by the de novo production of nitric oxide.

¹ Supported in part by National Institutes of Health grants HL49210, HL57653, HD33255, and HD38843. This study is in partial fulfillment of the M.S. degree for T.C.G.

² Correspondence: Ronald R. Magness, Department of Obstetrics and Gynecology, University of Wisconsin, Perinatal Research Laboratories, 7E Meriter Hospital, 202 South Park Street, Madison, WI 53715. FAX: 608 257 1304; rmagness{at}wisc.edu

This article has been cited by other articles:

				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]

				R. R. Magness, T. M. Phernetton, T. C. Gibson, and D.-b. Chen Uterine blood flow responses to ICI 182 780 in ovariectomized oestradiol-17{beta}-treated, intact follicular and pregnant sheep J. Physiol., May 15, 2005; 565(1): 71 - 83. [Abstract] [Full Text] [PDF]

				M. J. Byers, A. Zangl, T. M. Phernetton, G. Lopez, D.-b. Chen, and R. R. Magness Endothelial vasodilator production by ovine uterine and systemic arteries: ovarian steroid and pregnancy control of ER{alpha} and ER{beta} levels J. Physiol., May 15, 2005; 565(1): 85 - 99. [Abstract] [Full Text] [PDF]

				K. A. Vonnahme, M. E. Wilson, Y. Li, H. L. Rupnow, T. M. Phernetton, S. P. Ford, and R. R. Magness Circulating levels of nitric oxide and vascular endothelial growth factor throughout ovine pregnancy J. Physiol., May 15, 2005; 565(1): 101 - 109. [Abstract] [Full Text] [PDF]

				W. X. Liao, R. R. Magness, and D.-b. Chen Expression of Estrogen Receptors-{alpha} and -{beta} in the Pregnant Ovine Uterine Artery Endothelial Cells In Vivo and In Vitro Biol Reprod, March 1, 2005; 72(3): 530 - 537. [Abstract] [Full Text] [PDF]

				F.-X. Yi, R. R. Magness, and I. M. Bird Simultaneous imaging of [Ca2+]i and intracellular NO production in freshly isolated uterine artery endothelial cells: effects of ovarian cycle and pregnancy Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2005; 288(1): R140 - R148. [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]