Decreased femoral arterial flow during simulated microgravity in the rat.
To determine whether the blood supply to the hindlimbs of rats is altered by the tail-suspension model of weightlessness, rats were chronically instrumented for the measurement of femoral artery flow. Ultrasonic transit-time flow probes were implanted into 8-wk-old Wistar-Furth rats under ketamine-xylazine anesthesia, and, after 24 h of recovery, flow was measured in the normal ambulatory posture. Next, rats were suspended and flow was measured immediately and then daily over the next 4-7 days. Rats were subsequently returned to normal posture, and flow was monitored daily for 1-3 days. Mean arterial flow decreased immediately on the rats being suspended and continued to decrease until a new steady state of approximately 60% of control values was attained at 5 days. On the rats returning to normal posture, flow increased to levels observed before suspension. Quantile-quantile plots of blood flow data revealed a decrease in flow during both systole and diastole. The observed decrease in hindlimb blood flow during suspension suggests a possible role in the etiology of muscular atrophy and bone loss in microgravity.
Roer
R D
RD
Center for Marine Science Research, University of North Carolina at Wilmington 28403.
Dillaman
R M
RM
D000222:Adaptation, Physiological; D000818:Animals; D005260:Female; D005263:Femoral Artery / Q000502:physiology*; D006614:Hindlimb / Q000098:blood supply; D008297:Male; D051381:Rats; D011920:Rats, Inbred WF; D012039:Regional Blood Flow / Q000502:physiology; D013623:Tail / Q000502:physiology; D014893:Weightlessness / Q000009:adverse effects*