Morphologic changes of the uteroplacental unit in preeclampsia-like syndrome in rats.
OBJECTIVE
Chronic administration of the nitric oxide synthase inhibitor NG-nitro-L-arginine methylester (L-NAME) induces a preeclampsia-like syndrome in rats. This animal study aims to determine whether L-NAME-induced preeclampsia-like syndrome is also associated with morphologic changes in the uteroplacental unit.


METHODS
Mating was induced in 20 adult Sprague-Dawley rats. On day 14, five pregnant rats were randomly assigned to receive L-NAME, whereas six served as controls. Weight, continuous blood pressure, urine volume, urine protein content, litter size, number of resorption sites, placental weight, and weight of pups were documented. Uteroplacental tissue of three L-NAME and three control animals were processed for microscopy using corrosion cast technique.


RESULTS
The L-NAME-treated animals had a significantly smaller litter size (p=.033) and a significantly higher number of resorption sites (p=.021) when compared to controls. In L-NAME-treated rats midlength inner-diameter of maternal arterial channels (p<.001) and cross-sectional area (p<.001) were significantly smaller than were those in controls.


CONCLUSIONS
Chronic administration of L-NAME to pregnant rats is associated with significant morphologic changes of the uteroplacental vasculature. The L-NAME-induced pathologic alterations resulted in decreased litter size and increased number of resorption sites that may be contributed to diminished uteroplacental perfusion.
Mayr
Andreas J
AJ
Department of Anaesthesia and Critical Care Medicine, Innsbruck Medical University, Anichstrasse 35, 6020, Innsbruck, Austria. Andreas.J.Mayr@uibk.ac.at
Lederer
Wolfgang
W
Wolf
Hannes J
HJ
Dünser
Martin
M
Pfaller
Kristian
K
Mörtl
Manfred G
MG
D000818:Animals; D001835:Body Weight; D004195:Disease Models, Animal; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D008098:Litter Size; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000037:antagonists & inhibitors*; D010920:Placenta / Q000473:pathology*; D021041:Placental Circulation / Q000502:physiology; D011225:Pre-Eclampsia / Q000473:pathology* / Q000503:physiopathology; D011247:Pregnancy; D011270:Pregnancy, Animal; D011336:Probability; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D012680:Sensitivity and Specificity; D013577:Syndrome; D014599:Uterus / Q000098:blood supply / Q000473:pathology*
D009569:Nitric Oxide; D019331:NG-Nitroarginine Methyl Ester