The Reduced Uterine Perfusion Pressure (RUPP) Model of Preeclampsia Causes Decreased Capillary Perfusion in Skeletal Muscle

Abstract

The Reduced Uterine Perfusion Pressure (RUPP) model of preeclampsia exhibits angiogenic imbalance, endothelial dysfunction, increased vascular resistance and hypertension. We hypothesized the RUPP model would also exhibit decreased functional capillary density and perfusion in skeletal muscle. 
 Female Sprague‐Dawley rats (n=30) were randomized to nonpregnancy (NP) or breeding (Preg) at 12 weeks of age and again to RUPP or SHAM surgeries on gestational day (GD) 14 (or equivalent age in NP rats). On GD 20 (or equivalent), capillary structure and perfusion of the extensor digitorum longus was imaged using digital intravital video microscopy. Functional videos were analyzed by a blinded observer. Capillary density (CD) was expressed as capillaries/millimeter intersecting 3 staggered reference lines (150µm). Flow was scored as the percentage of capillaries having: 1) continuous, 2) intermittent, or 3) stopped flow. 
 Total CD was not different between groups. The RUPP model decreased continuous flow vessels (main effect of surgery, P<0.01) and increased stopped flow (main effect, p<0.01) both which were more pronounced in Preg animals (Continuous: Preg‐SHAM = 80.1±7.8% vs Preg‐RUPP = 67.8±11.2%, p<0.05) (Stopped: Preg‐SHAM = 8.7±3.2% vs Preg‐RUPP = 17.9±5.7% p<0.01). 
 Our results demonstrate that the RUPP model of preeclampsia (and not just general hypoperfusion) is associated with a decreased capillary perfusion in skeletal muscle. 
 Supported by AIHS, Olympus and Q‐Imaging