Repercussion of acetylsalicylic acid during fetal development on later renal hemodynamics of rats.

Acetylsalicylic acid (ASA) during pregnancy reaches the fetus. It seems important to know possible repercussions of ASA on later renal function of the offspring, as well as repercussions of this drug on factors that may influence fetal development, such as maternal plasma volume and placental oxidative stress. It was evaluated whether ASA changes maternal plasma volume and/or placental oxidative stress, fetal weight and renal function of the offspring at adult life. ASA (100 mg/kg/day, p.o., dissolved in ETOH 10%) or ETOH 10% was administered to Wistar rat dams, from the day 7 to day 20 of pregnancy/parturition. Plasma volume and the placental oxidative stress were evaluated on day 20 of pregnancy, using, respectively, the Evans blue dye and the thiobarbituric acid reactive substances methods. Mean arterial pressure, renal blood flow (RBF) and glomerular filtration rate (GFR) were evaluated in the anesthetized offspring, at the age of 90 days, using a blood pressure transducer, a flow probe and inulin clearance respectively. Plasma volume was 76% (P < 0.05) higher in ASA compared with that in control dams, but placental oxidative stress was the same for both groups. Fetal body weight, the number of nephrons, GFR, RBF and renal vascular resistance were similar for the same gender among the offspring of the two groups. However, reduced hematocrit (9.8%, P < 0.05), increased renal plasma flow (27%, P < 0.05) and reduced filtration fraction (32%, P < 0.05) were seen in the female offspring. In conclusion, although ASA had increased maternal plasma volume, it did not change nephrogenesis nor GFR in the adult offspring. The changes in renal plasma flow and filtration fraction seen in the ASA female offspring might partially be due to the reduced hematocrit.