Overall studies in humans, in vitro, and in animal models have yielded interesting hypotheses surrounding the placenta as an independent factor in the development of pre-eclampsia. Animal models, in conjunction with genetic studies in humans,[113] will likely elucidate an important underlying mechanism(s) for the disease.

To model the presumed decrease in placental perfusion buy PLX4032 that occurs as part of the mechanism proposed to incite pre-eclampsia,[130] workers have ligated various levels of the uterine artery. The RUPP or reduced uterine perfusion pressure model (reviewed in[131]) is performed in rats and several other animals. In rats, the model is performed at around 14 days of gestation by placing a clip above the aortic bifurcation and on both sides of the uterine arcade to prevent utero-ovarian collateral flow. This results in a 40%

or more reduction in flow to the developing fetal-placental units, and the resulting disease includes hypertension, renal damage (proteinuria), increased vascular reactivity, and small pups. In rats, an alternative of this model is based on increased salt intake click here and administration of desoxycorticosterone acetate,[132] which generates hypertension, convulsions, proteinuria, and renal lesions.[133] Other rodent models of reduced vascular function have utilized injection of inhibitors of nitric oxide [i.e. L-NAME (N-omega-nitro-l-arginine methyl ester[134])], or overexpression of soluble VEGF receptor (sVEGFRI, sFLT1) or members of the transforming growth factor

β receptor complex (i.e. endoglin). Adenovirus-driven overexpression of sFLT1 in pregnant rats leads to hypertension and proteinuria in a dose-dependent manner,[135] and this is enhanced by overexpression of soluble endoglin.[136] Other animals have also been used to develop models of pre-eclampsia. In guinea pigs, there have been reports Reverse transcriptase of a naturally occurring pre-eclampsia-like syndrome.[137] In addition, it has been observed that banding of the uterine arteries as well as transaction of the ovarian arteries before pregnancy results in later pregnancy hypertension, proteinuria, and elevated creatinine.[138] Moreover, early observations of constriction of the aorta in pregnant rabbits revealed that such manipulation generated hypertension, proteinuria, weight gain, and reduced weight of the fetus.[139] Finally, sheep experience what is called toxemia of pregnancy that appears to be a very different metabolic disorder as compared to pre-eclampsia,[140] but does include proteinuria and inflammation.