Effects of a Pre‐Clinical Model of Prostate Cancer on Left Ventricular Function in Sedentary and Exercise Trained Rats

Background Prostate cancer is the most common type of non‐skin cancer found in men making it a primary area of concern. Preliminary evidence suggests prostate cancer independent of treatment has atrophic effects on whole heart and left ventricular (LV) mass which are associated with reduced endurance exercise capacity in rats, highlighting a major area of concern. Using a pre‐clinical orthotropic model of prostate cancer, echocardiography was used to test the hypothesis that prostate cancer would impact LV function. We also investigated whether moderate exercise training would attenuate any detriments seen in LV function with prostate cancer. Methods Dunning R‐3327 AT‐1 prostate cancer cells (1×10 4 ) were cultured and harvested for injection in 0.1 ml of physiological saline solution in the ventral lobe of 3–4 month‐old male Copenhagen rats (n=19). These animals were randomized into 2 groups, Tumor Bearing Exercise (TBEX) n=10 or Tumor Bearing Sedentary (TBS) n=9. After ~1‐week recovery, TBEX animals began exercise on a treadmill at 15 m/min with a 15° incline for 60 min/day for ~30 days. Twenty additional cancer free controls were randomized into exercise control (EXC) (n=10) or Sedentary control (SEDC). Pre‐surgery (V1), and ~30 days post exercise commencement (V3) animals underwent echocardiographic evaluation using the parasternal short axis view to examine ventricle dimensions via a commercially available system (Vivid S6, GE Health Care). Results There were no significant differences in tumor mass between groups (TBEX 8.62±1.7g, TBS 6.6±1.3g p=0.29), or body weights (TBEX 299±9g, TBS 284±6g p=0.22) and (EXC 351±5g, SEDC 341±7g). There were no significant differences for V1 for any measures of LV function for all 4 groups. From V1–V3 EXC had significant increases in SV (103±5 ul, 126±7 ul, p=0.003) while SEDC had no significant difference (114±3 ul, 111±10 ul, p=0.78). SV for TBEX and TBS did not significantly change from V1–V3, but at V3 TBEX had significantly larger SV (TBEX=116±6 ul, TBS= 99±5 ul, p=0.022). Strain and strain rate were not significantly different from V1–V3 for all groups, however the strain (p=0.001) and strain rate (p=0.005) were both significantly different between control groups. Conclusion Information gleaned from the current investigation suggests prostate cancer itself does not significantly reduce left ventricular function in sedentary animals. However, increases in left ventricular function found in normal healthy exercise trained animals was reduced in tumor bearing animals performing the same exercise regime. Support or Funding Information American Cancer Society RSG 14‐150‐1‐CCE (BJB) This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .