Differential expression of endothelial nitric oxide synthase in coronary and cardiac tissue in hypoxic fetal guinea pig hearts

作者：Dong Yafeng; Thompson Loren P^*

来源：Journal of the Society for Gynecologic Investigation, 2006, 13(7): 483-490.

DOI：10.1016/j.jsgi.2006.06.005

• fetus
• cardiomyocyte
• coronary artery
• endothelium
• chronic hypoxia

OBJECTIVE: The purpose of the present study was to quantify the effect of chronic hypoxia on endothelial nitric oxide synthase (eNOS) gene and protein expression of fetal corollary artery segments and cardiac tissue of fetal guinea pig hearts.
METHODS: Time-mated pregnant guinea pigs (term = 65 days) were housed in room air (NMX, n = 6) or in a hypoxic chamber containing 10.5% O-2 for 14 days (HPX14, n = 6). At near term (60 days gestation), fetuses were excised from anesthetized animals via hysterotomy and hearts were removed and weighed, Both coronary, artery segments and cardiac ventricle were excised from the salute hearts, frozen, and stored at -80C until ready for study. eNOS inRNA was quantified using real-time polymerase chain reaction (PCR) based oil SYBR Green I labeling (BioRad Laboratories, Hercules, CA) using eNOS printers obtained front GeneBank normalized to 18S. eNOS proteins were quantified by Western immunoblotting using eNOS antibody (1:200) and normalized to normoxic controls. eNOS cell-specific localization in the fetal guinea pig heart was performed by double immunnofluorescence staining.
RESULTS: Both coronary artery endothelial cells (EC) and cardiomyocytes (CM) but not vascular smooth muscle cells of normoxic hearts exhibited positive immunnostaining of eNOS protein. Chronic hypoxia significantly (P < .05) increased both eNOS mRNA and protein levels of corollary artery segments (by 210.6% and 51.4%, respectively) butt decreased (P <. 05) mRNA and protein of cardiac tissue (by 50.0% and 40.6%, respectively) in the same hearts.
CONCLUSIONS: Chronic fetal hypoxia, after 14 days, induces sustained changes in eNOS gene and eNOS protein expression that differ between coronary and cardiac tissue in the fetal guinea pig heart. This soidy stuggests that while the functional roles of altered eNOS expression in hypoxic fetal hearts remain unclear, the site at which eNOS expression is altered may be important ill the adaptive response of the fetal heart. to hypoxia.

• 出版日期2006-10