Reduced uterine perfusion pressure model is not successful to mimic severe preeclampsia

Abstract

The aim of the study was to investigate maternal (hemoglobin, hematocrit, and biochemical parameters of blood and urine) and fetal parameters (number and weight of alive fetus) of preeclampsia in a rat model. Placental oxidative stress markers (protein carbonyl, malondialdehyde) and placental antioxidant values (CuZn-superoxide dismutase, glutathione peroxidase) were also measured. Preeclampsia was induced experimentally in timed-pregnant Sprague-Dawley rats by using the reduced uterine perfusion pressure (RUPP) model. Placental oxidative stress that plays a key role in the pathophysiology of placenta-related disorders, most notably preeclampsia (PE) and intrauterine growth restriction (IUGR) were demonstrated by using RUPP model. On day 14 of gestation, silver clips were placed around the aorta below the renal arteries and on the left and right uterine arcade at the ovarian artery. In the RUPP model animals (n = 15), when compared with the normotensive controls (n = 15), arterial pressure on day 19 of gestation was significantly higher in the RUPP rats (151.7 ± 17.6 mmHg) than normal pregnant rats (113.9 ± 11.4 mmHg). The RUPP rats showed a significant increase in protein excretion when compared with the normal pregnant rats (0.3 ± 0.04 vs 0.47 ± 0.07 g/dL) (p < 0.05). Associated with the hypertension in RUPP rats, placental levels of malondialdehyde (2.4 ± 0.2 vs. 1.6 ± 0.2 umol/gm tissue) and protein carbonyl (1.4 ± 0.3 vs. 0.9 ± 0.3 nmol/mg protein) were increased, while superoxid dismutase (0.03 vs 0.42 U/mg protein) and glutathione peroxidase (1.04 ± 0.31 vs 0.76 ± 0.22 U/g protein) were decreased. Pup number (6.6 ± 3.1 vs. 9.93 ± 2.0) and litter weight (17.4 ± 7.7 vs. 22.9 ± 6.7 g) were lower in the preeclamptic group. None of the complete blood counts and biochemical values other than sodium and chlorine were significantly different in preeclamptic group. Our findings suggest that the RUPP model cannot mimic severe preeclampsia; however, further studies using different settings may be helpful to obtain a preeclampsia model that is capable of successfully producing severe preeclampsia findings.