Morphofunctional Characteristics of the Placenta in Experimental Preeclampsia

The aim was to characterize morphological and functional changes in the placenta in midpregnancy when modeling experimental preeclampsia and evaluate the model for validity. Material and methods. The study was conducted on 12–14-week-old mice of the inbred CBA, DBA/2, Balb/c lines. Uncomplicated pregnancy was modeled using the ♀CBA×♂Balb/c combination, preeclampsia was reproduced by the ♀CBA×♂DBA/2 combination and the introduction of 0.1 ml of 0.9% NaCl solution of beta-heptylglycoside muramyl dipeptide (C7MDP) intraperitoneally at the dose of 25 μg per 1 animal on days 5 and 7 of gestation (DG). On day 14 of gestation, the frequency of fetal resorption and the level of proteinuria were determined, and the placentas were dissected. Placenta preparations were stained with hematoxylin and eosin. Freshly isolated placenta was also examined using scanning electron microscopy, placenta homogenate was used to measure ex vivo cytokine production using flow cytofluorimetry. After birth of the offspring, the fetuses were weighed on the 1st day of life and the crown-rump length was measured. The obtained results were statistically processed using the Sigma Stat 3.5 program. Results. The proteinuria level was 0.1 (0.0; 0.1) g/l in cases of uncomplicated pregnancy and 1.0 (1.0; 3.0) g/l in pregnancy complicated by preeclampsia. On the 14th day of pregnancy, the resorption rate in cases of the uncomplicated pregnancy group was 12.9%, in group of experimental preeclampsia we revealed 39.34% ones. Morphometric study showed intrauterine growth retardation of the fetuses in the experimental preeclampsia group. Our study of cytokines estimating in placental homogenates showed that pregnancy complicated by experimental preeclampsia was accompanied by significant increase in the level of the proinflammatory cytokine IL-1, as well as decrease in the pleiotropic cytokines IL-4 and IL-6 and anti-inflammatory IL-10. Using light and scanning electron microscopy we found morphological and functional changes in the placenta in experimental preeclampsia reflecting the signs of placental insufficiency. Conclusion. The changes we observed allow us to classify the considered model of preeclampsia as one of the most adequate at present. Having high reproducibility and validity, it can contribute to the search for new diagnostic and therapeutic targets for this pregnancy complication.

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