Document Detail

Nitric oxide modulates angiotensin II-induced drinking behavior in the near-term ovine fetus.
MedLine Citation:
PMID:  10739535     Owner:  NLM     Status:  MEDLINE    
OBJECTIVE: Human and ovine fetuses demonstrate an enhanced rate of spontaneous and angiotensin II-stimulated swallowing. Angiotensin II and nitric oxide synthase have been localized to thirst centers in the brain. This study was performed to determine whether central nitric oxide contributes to the regulation of angiotensin II-induced fetal swallowing. STUDY DESIGN: Six pregnant ewes with near-term singleton fetuses were chronically prepared with fetal vascular and lateral ventricle catheters and electrocorticogram and esophageal electromyogram electrodes. After a 2-hour control period, fetuses were administered serial lateral ventricle injections (1 mL) of angiotensin II (3.2 microg; time, 2 hours) and N omega-nitro-L -arginine methyl ester (3 mg; time, 3 hours) and a repeat angiotensin II injection (3.2 microg; time, 5 hours). All fetuses received an additional control study of lateral ventricle injections of artificial cerebrospinal fluid on a previous day. RESULTS: Angiotensin II injection significantly increased mean +/- SEM fetal swallowing (0.9 +/- 0.1 to 2.7 +/- 0.4 swallows/min). N omega-nitro-L -arginine methyl ester significantly decreased fetal swallowing to below the basal rate (0.4 +/- 0.1 swallows/min), and swallowing did not increase with the second angiotensin II dose (in the presence of nitric oxide blockade). CONCLUSIONS: These results demonstrate that inhibition of central nitric oxide suppresses fetal swallowing behavior in response to central angiotensin II. We speculate that tonic nitric oxide facilitates angiotensin II swallowing stimulation by maintenance of glutamate activation of hypothalamic N -methyl-D -aspartate receptors.
M A El-Haddad; C R Chao; S x Ma; M G Ross
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  American journal of obstetrics and gynecology     Volume:  182     ISSN:  0002-9378     ISO Abbreviation:  Am. J. Obstet. Gynecol.     Publication Date:  2000 Mar 
Date Detail:
Created Date:  2000-05-02     Completed Date:  2000-05-02     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0370476     Medline TA:  Am J Obstet Gynecol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  713-9     Citation Subset:  AIM; IM    
Perinatal Research Laboratories, Harbor-University of California, Los Angeles Medical Center, University of California, Los Angeles School of Medicine, Torrance, CA 90502, USA.
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MeSH Terms
Angiotensin II / administration & dosage,  pharmacology*
Behavior, Animal / drug effects
Deglutition / drug effects
Drinking Behavior / drug effects
Enzyme Inhibitors / pharmacology
Fetus / drug effects
Gestational Age
Injections, Intraventricular
NG-Nitroarginine Methyl Ester / pharmacology
Nitric Oxide / physiology*
Grant Support
Reg. No./Substance:
0/Enzyme Inhibitors; 10102-43-9/Nitric Oxide; 11128-99-7/Angiotensin II; 50903-99-6/NG-Nitroarginine Methyl Ester

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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