L-arginine attenuates blood pressure and reverses the suppression of angiogenic risk factors in a rat model of preeclampsia.

This study investigated the effect of L-arginine on blood pressure, angiogenic factors and liver enzymes in pregnant rats administered L-NAME. Thirty-six female Sprague-Dawley rats weighing between 150-170 g were divided into 4 groups of the control (normal saline), L-NAME (50 mg/kg b.w. intraperitoneal injection from days 13-18 of pregnancy), L-NAME + L-arginine (50 mg/kg b.w. and 1 g/kg b.w of L-arginine from days 13 to 18) and L-arginine (1 g/kg b.w administered orally from days 13 to 18). Urine samples were collected on day 18 of pregnancy and the animals were sacrificed on day 19 of pregnancy for blood pressure parameters, angiogenic and liver enzyme assays. L-NAME increased protein, albumin, systolic and diastolic blood pressure significantly when compared with control. This effect was reversed by L-arginine when co-administered with L-NAME (p < 0.05). No difference was found in the pulse pressure and heart rate in all the groups as well as ALP and ALT levels. However, AST levels were significantly decreased in L-Arginine (L-Arg) administered rats when compared with control. VEGF and PIGF levels were decreased in the L-NAME administered rats, while this levels were increased in the L-NAME + L-Arg group and L-Arg group when compared with the L-NAME alone group (p < 0.05). sVEGFR-1 level was increased in L-NAME administered rats when compared to control, while in the L-NAME + L-Arg group and L-Arg group the level of sVEGFR-1 was significantly decreased when compared to L-NAME alone group. This study showed that L-arginine supplementation in pregnancy reduced the preeclampsia-like symptoms exhibited by L-NAME in pregnant rats.