Resting cellular and physiological effects of freewheel running.
OBJECTIVE
Exercise modulates many aspects of physiology. The purpose of the current experiment was to characterize the impact of regular, moderate physical activity on resting, baseline measures of cellular immunity blood lipids, and muscle enzyme.


METHODS
Male Fischer 344 rats were housed with either mobile (run, N = 10) or immobile (sedentary, N = 10) running wheels. After 4 wk of running, rats were sacrificed. Blood and muscle (long and medial heads of the triceps) were collected. From blood, white blood cell (WBC) differentials, red blood cell (RBC) count, hemoglobin, hematocrit, and lipid profiles were measured. Muscle citrate synthase (CS) activity was measured by spectrophotometric analysis.


RESULTS
Rats ran an average of 9.89 +/- 0.79 km.wk(-1). There were no differences in the total number of circulating WBC, RBC, or eosinophils. Freewheel running decreased the number of circulating neutrophils (P < 0.001), monocytes (P < 0.01), and basophils (P < 0.01), while increasing the number of lymphocytes (P < 0.001), when compared with sedentary animals. Mean corpuscular content of hemoglobin was elevated in the freewheel group (P < 0.01). Physically active animals had slightly lower triglycerides and LDL, and elevated HDL. These changes resulted in a significant improvement in LDL/HDL ratio (P < 0.05). Muscle CS activity was unchanged between groups.


CONCLUSIONS
Both the alterations in the RBC hemoglobin and lipid proteins are positive health changes associated with exercise training. The impact of the alterations in WBC differentials remains unknown but could indicate a reduction in inflammatory load. In conclusion, freewheel running provides sufficient exercise stimulus to produce some, but not all, training associated physiological adaptations.
Kennedy
Sarah L
SL
Department of Integrative Physiology, University of Colorado at Boulder, Boulder, CO 80309, USA.
Smith
Taro P
TP
Fleshner
Monika
M
D000818:Animals; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D002950:Citrate (si)-Synthase / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism; D007962:Leukocytes / Q000378:metabolism; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D018482:Muscle, Skeletal / Q000201:enzymology; D010805:Physical Conditioning, Animal / Q000502:physiology; D051381:Rats; D011916:Rats, Inbred F344; D013053:Spectrophotometry; D014280:Triglycerides / Q000097:blood
D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D006454:Hemoglobins; D014280:Triglycerides; D002950:Citrate (si)-Synthase