Abstract 270: Exercise During Pregnancy Restores Angiogenic Balance But Does Not Lower Blood Pressure in Rupp Hypertensive Rats

Abstract

Although clinical studies suggest women continuing to exercise during pregnancy have a decreased incidence of preeclampsia, little is known regarding the effects of an exercise regimen started at the onset of pregnancy. Our laboratory has previously reported voluntary wheel running in rats for 6 weeks before and during (EBD) pregnancy increases circulating free vascular endothelial growth factor (VEGF), restores angiogenic potential, and attenuates placental ischemia induced hypertension. Our hypothesis was exercise during (ED) pregnancy without previous exercise training would decrease blood pressure and restore angiogenic potential in pregnant rats with reduced uterine perfusion pressure (RUPP)-induced hypertension. Rats were given free access to running wheels upon confirmation of pregnancy, and running distance was monitored weekly. RUPP (n = 10) or Sham (n= 10) surgery was performed on day 14 of gestation (term=21). Arterial pressure (AP) was measured via indwelling catheter in conscious rats and tissues were collected on day 19. Serum angiogenic potential was assessed with an endothelial tube formation assay using human umbilical vascular endothelial cells (HUVEC). RUPP increased AP compared to Sham (123±2 vs 105±3 mmHg; P<0.05) and AP was not altered in the RUPP+ED (n=8; 117±4mmHg) or Sham+ED (n = 7; 98±3 mmHg). RUPP decreased free VEGF compared to Sham and Sham+ED rats (465.4 vs 842.9 vs 809.8 pg/ml; P<0.05) and this was restored in the RUPP+ED (809.8 pg/ml). Exercise increased (P<0.05) free VEGF in the RUPP but not the Sham rats. HUVEC tube length was decreased in RUPP compared to Sham and Sham+ED rats (61194 vs 74865 vs 79318 μm; P<0.05) and this reduction was attenuated in the RUPP+ED (71552 μm) rats. RUPP, RUPP+ED and Sham+ED had decreased fetal weight compared to Sham (2.3 vs 2.0 vs. 2.2 vs 2.2 vs2.6g; P<0.05). In contrast to our previous report that exercise before and during pregnancy increased free plasma VEGF in normal pregnant and sham rats and decreased AP and restored angiogenic balance in RUPP rats, the present data demonstrate that an exercise regimen started at pregnancy in rats that are exercise naïve at conception has both beneficial and detrimental effects on maternal-fetal outcomes in a gestation complicated by placental-ischemia.