Document Detail

Effect of antenatal dexamethasone on the expression of endothelial nitric oxide synthase in the lungs of postnatal pups.
MedLine Citation:
PMID:  11339671     Owner:  NLM     Status:  MEDLINE    
Activities of endothelial nitric oxide synthase (eNOS) are developmentally regulated and its presence at birth may play a role in the transition of cardiopulmonary circulation. Antenatal dexamethasone (Dex) therapy accelerates fetal lung maturation. We speculate that Dex therapy may enhance pulmonary eNOS protein expression in the newborn. This article examines whether antenatal Dex therapy affected the expression of eNOS in the lungs of rat pups in the postnatal period. Time-dated pregnant Wistar rats were subjected to 2 doses of Dex (0.8 mg/kg, intramuscularly, daily) or equivalent volume of normal saline at the 18th and 19th gestational day and delivered naturally. The newborn pups were randomly assigned to 4 groups by age: days 1, 3, 5, and 7. After homogenization, abundance of eNOS protein in lungs was determined by Western blot analysis. There were 7 dams in each group. Mean body weights of the pups in the Dex group were lighter than those in the control at birth and remained stunted up to day 7 (5.68+/-0.47 g v 6.34+/-0.47 g, P <.01). However, there were no differences in wet lung weights and lung/body weight ratios between both groups in the study period. Abundance of eNOS protein expression decreased in both the control and Dex groups (P < .01). Pups that received antenatal Dex had 39% more in abundance of eNOS protein expression in lungs when compared to the control on day 1 (P < .05) but there were no differences between both groups from day 3 to 7. We conclude that antenatal Dex therapy enhances the abundance of eNOS protein expression in the lung at birth and could be a factor in improving respiratory functions in infants who received antenatal steroid therapy.
C H Lin; M L Tsai; S J Chou; T F Yeh
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Seminars in perinatology     Volume:  25     ISSN:  0146-0005     ISO Abbreviation:  Semin. Perinatol.     Publication Date:  2001 Apr 
Date Detail:
Created Date:  2001-05-07     Completed Date:  2001-09-27     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7801132     Medline TA:  Semin Perinatol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  94-9     Citation Subset:  IM    
Department of Pediatrics and Physiology, Medical College National Cheng Kung University, Tainan, Taiwan.
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MeSH Terms
Animals, Newborn*
Blotting, Western
Dexamethasone / administration & dosage,  pharmacology*
Glucocorticoids / administration & dosage,  pharmacology*
Lung / drug effects,  embryology*,  enzymology*
Nitric Oxide Synthase / analysis*,  metabolism
Nitric Oxide Synthase Type III
Rats, Wistar
Reg. No./Substance:
0/Glucocorticoids; 50-02-2/Dexamethasone; EC Oxide Synthase; EC Oxide Synthase Type III; EC protein, rat

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