Meeting Abstract
65.9 Jan. 7 Effects of Experimental Erythropoietin Elevation on Voluntary Exercise and Maximal Aerobic Capacity in House Mice KOLB, EM*; KELLY, SA; MIDDLETON, KM; SERMSAKDI, LS; GARLAND, JR., T; Univ. of California, Riverside zookolb@yahoo.com
Voluntary exercise is a complex trait involving numerous subordinate characters, both behavioral and physiological. We have used artificial selection for voluntary exercise to explore evolutionary correlates of a high-activity phenotype. The model is comprised of four replicate lines of house mice selected for high-voluntary wheel running (HR lines) and four replicate lines of non-selected control mice (C lines). Previous work has shown that HR lines run voluntarily on wheels closer to their estimated maximum aerobic capacity (VO2max) than C lines, and that plasma hemoglobin (Hb) concentration is positively correlated with VO2max in forced-exercise trials in HR lines, but negatively correlated in C lines. Given that oxygen availability may be limiting exercise capacity, we tested whether voluntary exercise and VO2max changed in response to an experimental elevation of Hb concentration. The long-acting, recombinant human erythropoietin (EPO) darbepoetin alfa (Amgen Inc.) was administered by intraperitoneal injection to female mice (N = 96) from both HR and C lines at doses of 0 (vehicle control), 100, and 300 ug/kg. Resulting Hb levels were increased by approximately 40 % in both groups HR and C lines. Changes in voluntary exercise and maximal aerobic capacity will be reported. Supported by Amgen Inc. and NSF IOB-0543429 to T.G.
