Document Detail


Blockade of PGHS-2 inhibits the hypothalamus-pituitary-adrenal axis response to cerebral hypoperfusion in the sheep fetus.
MedLine Citation:
PMID:  19297537     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Decreases in fetal blood pressure stimulate homeostatic stress responses that help return blood pressure to normal levels. Fetal hypothalamus-pituitary-adrenal (HPA) axis responses to hypotension are mediated by chemoreceptor and baroreceptor reflexes and ischemia of the fetal central nervous system. Indomethacin, a nonselective inhibitor of prostaglandin endoperoxide synthase (PGHS)-1 and -2, attenuates the HPA response to hypotension in the fetus. The present study was designed to test the hypothesis that selective inhibition of PGHS-2 also inhibits the HPA response to cerebral hypoperfusion. We studied 13 chronically catheterized fetal sheep (126-136 days gestation). Five fetal sheep were subjected to intracerebroventricular infusion of nimesulide (0.01 mg/day), a specific inhibitor of PGHS-2, and eight were treated with vehicle (DMSO in water) for 5 days. Each fetus was subjected to a 10-min period of brachiocephalic occlusion, which decreased carotid arterial pressure approximately 75% and reflexively increased fetal plasma concentrations of ACTH, POMC, cortisol, and femoral arterial pressure, and decreased fetal heart rate. Nimesulide significantly inhibited the ACTH response to the BCO, while significantly augmenting the reflex cardiovascular response and altering fetal heart rate variability consistent with increased sympathetic nervous system activity. The results of this study demonstrate that the activity of PGHS-2 in the brain is a necessary component of the fetal HPA response to cerebral hypoperfusion in the late-gestation fetal sheep. These results are consistent with those of recent study, in which we demonstrated that the preparturient increase in fetal ACTH secretion depends upon PGHS-2 activity within the fetal brain.
Authors:
Charles E Wood; Melanie Powers Fraites; Maureen Keller-Wood
Related Documents :
12280687 - A dynamical model of labor-market change in international labor migrations when demand ...
2178917 - The effect of heart rate on doppler flow velocity systolic-diastolic ratios in umbilica...
19075097 - Hypertension produced by placental ischemia in pregnant rats is associated with increas...
8694077 - Fetal placental embolization in the late-gestation ovine fetus: alterations in umbilica...
3343547 - Abnormal orthostatic changes in blood pressure and heart rate in subjects with intact s...
11967717 - Ascending fractional pulse pressure closely relating to large artery function.
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2009-03-18
Journal Detail:
Title:  American journal of physiology. Regulatory, integrative and comparative physiology     Volume:  296     ISSN:  0363-6119     ISO Abbreviation:  Am. J. Physiol. Regul. Integr. Comp. Physiol.     Publication Date:  2009 Jun 
Date Detail:
Created Date:  2009-05-21     Completed Date:  2009-07-02     Revised Date:  2010-09-23    
Medline Journal Info:
Nlm Unique ID:  100901230     Medline TA:  Am J Physiol Regul Integr Comp Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  R1813-9     Citation Subset:  IM    
Affiliation:
Department of Physiology and Functional Genomics, PO Box 100274, University of Florida College of Medicine, Gainesville, FL 32610-0274, USA. woodc@ufl.edu
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adrenocorticotropic Hormone / blood
Animals
Baroreflex / drug effects
Blood Pressure / drug effects
Brachiocephalic Trunk / surgery
Brain / blood supply,  drug effects*,  embryology
Brain Ischemia / drug therapy*,  embryology,  enzymology,  physiopathology
Cerebrovascular Circulation / drug effects*
Cyclooxygenase 2 / metabolism*
Cyclooxygenase 2 Inhibitors / administration & dosage*
Disease Models, Animal
Fetal Blood / metabolism
Gestational Age
Heart Rate, Fetal / drug effects
Homeostasis
Hydrocortisone / blood
Hypotension / drug therapy*,  embryology,  enzymology,  physiopathology
Hypothalamo-Hypophyseal System / drug effects*,  metabolism
Infusions, Parenteral
Pituitary-Adrenal System / drug effects*,  metabolism
Pro-Opiomelanocortin / blood
Sheep
Sulfonamides / administration & dosage*
Grant Support
ID/Acronym/Agency:
HD33053/HD/NICHD NIH HHS; HD42135/HD/NICHD NIH HHS
Chemical
Reg. No./Substance:
0/Cyclooxygenase 2 Inhibitors; 0/Sulfonamides; 50-23-7/Hydrocortisone; 51803-78-2/nimesulide; 66796-54-1/Pro-Opiomelanocortin; 9002-60-2/Adrenocorticotropic Hormone; EC 1.14.99.1/Cyclooxygenase 2
Comments/Corrections

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


Previous Document:  Humanized-monoclonal antibody against heterologous Leptospira infection.
Next Document:  Phenobarbital blockade of the preovulatory luteinizing hormone surge: association with phase-advance...