Differential expression of placental and vascular endothelial nitric oxide synthase in an ovine model of fetal growth restriction

Juan A Arroyo, Russell V Anthony, Thomas A Parker, Henry L Galan
American Journal of Obstetrics and Gynecology 2006, 195 (3): 771-7

OBJECTIVE: The objective of the study was to evaluate endothelial nitric oxide synthase concentration in the placenta, uterine, and umbilical vessels near term in an ovine model of intrauterine growth restriction induced by hyperthermia beginning in early gestation.

STUDY DESIGN: Four pregnant ewes were exposed to hyperthermia conditions for 80 days beginning at 35 days gestation to induce intrauterine growth restriction. Four ewes were kept in ambient conditions as controls. Umbilical artery Doppler systolic to diastolic ratios were calculated. At 128 days gestation, fetal catheters were placed for aortic blood pressure measurements and blood gas determination. At 132 days gestation, fetal mean systemic blood pressure and gases were determined. Sheep placentomes, umbilical artery and vein, and uterine artery were assessed for endothelial nitric oxide synthase concentration and immunolocalization.

RESULTS: Compared with control pregnancies, the intrauterine growth restriction pregnancies showed: (1) reduced fetal and placental weights (P < or = .01); (2) elevated systemic blood pressure (41 +/- 1.53 mm Hg versus 44.3 +/- 1.71 mm Hg; P < or = .05) and systolic to diastolic ratios (3.0 +/- 0.34 versus 3.8 +/- 0.18; P < or = .01); (3) reduced fetal O2 saturation (52.2 +/- 7.03% versus 33.05 +/- 10.98%; P < or = .008); and (4) decreased endothelial nitric oxide synthase protein concentration in the umbilical artery (2.7-fold; P < or = .01) and a trend for a decrease in the uterine artery (1.4-fold; P < or = .1).

CONCLUSION: We conclude that placental endothelial nitric oxide synthase protein concentration is increased near term in our ovine model of intrauterine growth restriction, and that this increase may be secondary to hypoxia.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"