Acute exercise increases prostate tumor blood flow in rats

Abstract

During exercise there is a redistribution of blood flow within the body based upon the functional vascular compliance of a given tissue. Given the altered vasculature morphology within tumors (e.g., less smooth muscle), there may be a profound increase in tumor blood flow during exercise. We utilized vehicle control (CON; n=5) or tumor bearing (TB; n=6) Copenhagen rats to test whether prostate tumor perfusion increases during moderate intensity exercise. Dunning R‐3327 MatLyLu tumor cells were injected (104cells) into the ventral lobe of the prostate of TB animals and blood flow experiments performed 21 days later. Blood flow and vascular conductance to the tumor and prostate tissue was measured using radiolabelled microspheres at rest and during exercise (treadmill; 5 min @ 15 m/min, 10° incline). There was a marked increase in tumor blood flow during exercise (rest, 17 ± 2; exercise, 52 ± 5 ml/min/100 g; p<0.001). Tumor vascular conductance increased by ~ 270% from rest to exercise. Blood flow to the surrounding prostate tissue (TB) or the prostate (CON) did not change with exercise. This is the first investigation to demonstrate that tumor perfusion is significantly increased with exercise. The precise mechanisms for the increase perfusion (e.g., blunted vasoconstriction), and whether increase in blood flow during exercise affect tumor growth, remains to be determined. Support: NIH (AG‐31317); FBRP (1BN‐02).