Document Detail

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 sheep.
MedLine Citation:
PMID:  14985241     Owner:  NLM     Status:  MEDLINE    
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 (P(4))-controlled internal drug-releasing device (CIDR; 0.3 g) for 7 days. On Day 6 of P(4), sheep were given two prostaglandin F(2 alpha) 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 P(4), estradiol-17 beta (E(2)beta) 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 P(4) fell to baseline within 8 h of CIDR removal, while E(2)beta 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.
Tiffini C Gibson; Terrance M Phernetton; Milo C Wiltbank; Ronald R Magness
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.     Date:  2004-02-25
Journal Detail:
Title:  Biology of reproduction     Volume:  70     ISSN:  0006-3363     ISO Abbreviation:  Biol. Reprod.     Publication Date:  2004 Jun 
Date Detail:
Created Date:  2004-05-24     Completed Date:  2004-12-10     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0207224     Medline TA:  Biol Reprod     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1886-94     Citation Subset:  IM    
Department of Obstetrics and Gynecology, University of Wisconsin, Madison, 53706, USA.
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MeSH Terms
Blood Flow Velocity / drug effects,  physiology
Chorionic Gonadotropin / administration & dosage
Dinoprost / administration & dosage
Drug Implants
Estradiol / blood,  physiology*
Estrus / drug effects,  physiology*
Gonadotropins, Equine / administration & dosage
Luteinizing Hormone / blood
Models, Animal
Models, Biological
NG-Nitroarginine Methyl Ester / administration & dosage
Nitric Oxide / physiology*
Progesterone / administration & dosage,  blood
Uterus / blood supply*,  drug effects
Grant Support
Reg. No./Substance:
0/Chorionic Gonadotropin; 0/Drug Implants; 0/Gonadotropins, Equine; 10102-43-9/Nitric Oxide; 50-28-2/Estradiol; 50903-99-6/NG-Nitroarginine Methyl Ester; 551-11-1/Dinoprost; 57-83-0/Progesterone; 9002-67-9/Luteinizing Hormone

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