Effect of endurance training on nitric oxide synthase activity and expression in human placenta.

LORES ARNAIZ, S.; RAMÍREZ-VELEZ, R.; AGUILAR DE PLATA, A.C.; CZERNIZYNIEC, A.; BUSTAMANTE, J.

San Francisco

Congreso; 59th Annual Meeting and 3rd World Congress on Exercise in Medicine; 2012

Effect of endurance training on nitric oxide synthase activity and expression in human placenta.   Lores Arnaiz S**, Ramírez-Vélez R*, Aguilar de Plata AC*, Czerniczyniec A,** and Bustamante J**   *School of Medicine, University of Valle, Street 4B No. 36-00. Cali Colombia **Laboratory of Free Radical Biology, School of Pharmacy and Biochemistry, University of Buenos Aires, Junin 956, C1113AAD. Buenos Aires Argentina   Introduction: Many studies have documented that placental development is altered by a variety of environmental factors such as aerobic exercise training which alter placental bed blood flow and/or oxygen delivery. The placenta lacks innervation, thus vascular tone regulation depends on endothelial release of vasoactive molecules such as nitric oxide (NO). Although exercise-induced increases in blood flow and in endothelial nitric oxide synthase (eNOS) expression have been reported; it is not known if exercise produces the same effect in human placenta.  Objectives: To determine the effects of aerobic exercise training in the second half of pregnancy on eNOS expression and on NO production in human placenta.  Methods: This was a randomized, double-blinded, controlled clinical trial of 20 healthy primigravid women between 16 and 20 weeks' gestation. The training group (n=10) took part in aerobic exercise at an intensity of 50-65% of their maximum heart rate for 60 min, three times a week for 16 weeks. The control group (n=10) undertook their usual physical activity. A spectrophotometric assay was used to measure NOS activity in cytosolic samples from placental tissue and Western Blot technique was used to determine endothelial NOS expression.  Results: The ratio eNOS/b actin expression was 4-fold increased in cytosolic samples from exercised women. A 2-fold increase in NOS activity was observed in cytosolic samples from exercised women.  Conclusion: Training during pregnancy leads to an increase in eNOS expression and in total NO production in placental cytosol. Greater eNOS expression may also underlie the effects of exercise in the protection of gestational disorders associated to endothelial dysfunction.Trial registration. NCT00741312.