Interaction of alcohol & phosphatidic acid in maternal rat uterine artery function

Alcohol has been demonstrated to impair maternal uterine arterial adaptations in Fetal Alcohol Spectrum Disorder (FASD) animal models. However, the exact mechanism remains inconclusive. We hypothesized that phosphatidic acid (PA), a direct target of alcohol metabolism, would alleviate alcohol-induced vascular dysfunction of the maternal uterine artery. Mean fetal weight, and crown-rump length of the alcohol administered rats were ~9 % and 7.6 % lower than the pair-fed control pups, respectively. Acetylcholine (Ach)-induced uterine artery relaxation was significantly impaired in uterine arteries of alcohol-administered rats (P < 0.05). Supplementation of 10^-5 M PA reversed alcohol-induced vasodilatory deficit; no difference was detected after PA treatment between pair-fed control and alcohol groups (P = 0.37). There was a significant interaction between PA concentrations and alcohol exposure (PA X Alcohol effect, P < 0.0001). Pair-wise comparisons showed a concentration-dependent vasodilatory effect on uterine arteries of the alcohol-administered rats, with % relaxation significantly improved at PA concentrations > 10^-7 M (P < 0.05). Alcohol significantly reduced vasodilatory P-Ser1177 endothelial nitric oxide synthase (eNOS) levels in the uterine artery (↓90.7 %; P = 0.0029). PA treatment significantly reversed P-Ser1177 eNOS level in alcohol uterine arteries (153.7 %↑; P = 0.005); following ex vivo PA, there was no difference in P-Ser1177 eNOS levels between Control and Alcohol. Neither alcohol treatment nor PA affected total eNOS levels. Our data provide the first evidence of the interaction of alcohol and PA in rat maternal uterine artery vascular function and demonstrates PA's relationship with the eNOS system. Overall, the current study demonstrates that PA may be a promising therapeutic molecule of interest in alcohol-related gestational vascular dysfunction.