We investigated the efficacy and mechanisms of tadalafil, a selective phosphodiesterase 5 inhibitor, in treating preeclampsia (PE) with fetal growth restriction (FGR) using L-NG-nitroarginine methyl ester (L-NAME)-induced PE with FGR in pregnant mice as our experimental model.
C57BL/6 mice were divided into 2 groups 11 days postcoitum (d.p.c.). A control group of dams (C dam) received 0.5% carboxymethylcellulose (CMC). A L-NAME-treated group received 1 mg/ml L-NAME dissolved in CMC. The L-NAME-treated dams were divided into 2 subgroups 13 d.p.c. One subgroup continued to receive L-NAME (L dams). The other subgroup received L-NAME with 0.08 mg/ml tadalafil suspended in CMC (TL dams). Maternal systolic blood pressure (SBP) and proteinuria were assessed 16 d.p.c. Fetal weight was recorded, and placentas and maternal kidneys were collected 17 d.p.c.
Maternal SBP, proteinuria, and fetal weight were improved for TL dams compared to L dams. The placental concentration of placental growth factor (PlGF) was higher for TL dams than for the C and L dams. The placental maternal blood sinuses of L dams were narrower than those of C dams, but those of TL dams improved to a similar width as C dams. Glomerular oxidative stress was ameliorated in TL dams compared to L dams.
Tadalafil dilates the placental maternal blood sinuses, which leads to increase PlGF production, and contributes to facilitate fetal growth and improve maternal SBP. Moreover, tadalafil ameliorates glomerular damage by reducing oxidative stress. These results suggest that tadalafil is a candidate for treatment of PE with FGR.