L-Citrulline supplementation during pregnancy improves perinatal and postpartum maternal vascular function in a mouse model of preeclampsia

Preeclampsia is a spontaneously occurring pregnancy complication diagnosed by new-onset hypertension and end-organ dysfunction with or without proteinuria. This pregnancy-specific syndrome contributes to maternal morbidity and mortality and can have detrimental effects on fetal outcomes. Preeclampsia is also linked to increased risk of maternal cardiovascular disease throughout life. Despite intense investigation of this disorder, few treatment options are available. The aim of this study was to investigate the potential therapeutic effects of maternal L-citrulline supplementation on pregnancy-specific vascular dysfunction in the male C57BL/6J × female C57BL/6J C1q-/- preeclampsia-like mouse model. L-Citrulline is a nonessential amino acid that is converted to L-arginine to promote smooth muscle and blood vessel relaxation and improve nitric oxide (NO)-mediated vascular function. To model a preeclampsia-like pregnancy, female C57BL/6J mice were mated to C1q-/- male mice, and a subset of dams was supplemented with L-citrulline throughout pregnancy. Blood pressure, systemic vascular glycocalyx, and ex vivo vascular function were investigated in late pregnancy, and postpartum at 6 and 10mo of age. Main findings show that L-citrulline reduced blood pressure, increased vascular glycocalyx volume, and rescued ex-vivo vascular function at gestation day 17.5 in this preeclampsia-like model. The vascular benefit of L-citrulline also extended postpartum, with improved vascular function and glycocalyx measures at 6 and 10mo of age. L-Citrulline-mediated vascular improvements appear, in part, attributable to NO pathway signaling. Taken together, L-citrulline supplementation during pregnancy appears to have beneficial effects on maternal vascular health, which may have translational implications for improved maternal cardiovascular health.