Prostaglandin inhibition causes an increase in reactive hyperaemia after ischaemic exercise in human forearm.
The hypothesis that prostaglandins contribute to the reactive hyperaemia after 5 min of ischaemia or 5 min of ischaemic exercise was investigated in six men by inhibiting prostaglandin production with ibuprofen (1800 mg) and indomethacin (225 mg) over 24 h before testing. Blood flow was measured continuously in the baseline and after ischaemia by combined pulsed and echo Doppler as the product of velocity and cross-sectional area. After 5 min of ischaemia, there were no differences in blood flow between placebo and the two drug conditions, except at 5 and 10 s when flow with indomethacin was greater than both placebo and ibuprofen. After 5 min of ischaemic exercise, blood flow was significantly greater as a consequence of increased vascular conductance in each of ibuprofen and indomethacin than placebo from 5 until 90 s of recovery. We conclude that prostaglandin inhibition had little or no effect on reactive hyperaemia after 5 min of circulatory occlusion alone, but that blood flow after ischaemic exercise was elevated due to increased vascular conductance when prostaglandin synthesis was inhibited.
Naylor
H L
HL
Department of Kinesiology, University of Waterloo, Canada.
Shoemaker
J K
JK
Brock
R W
RW
Hughson
R L
RL
D000328:Adult; D016861:Cyclooxygenase Inhibitors / Q000008:administration & dosage; D005542:Forearm / Q000098:blood supply; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology*; D007052:Ibuprofen / Q000008:administration & dosage; D007213:Indomethacin / Q000008:administration & dosage; D007511:Ischemia / Q000503:physiopathology*; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply / Q000378:metabolism; D005082:Physical Exertion / Q000502:physiology*; D010974:Platelet Aggregation / Q000502:physiology; D011448:Prostaglandin Antagonists / Q000008:administration & dosage*; D011453:Prostaglandins / Q000378:metabolism*; D012039:Regional Blood Flow; D013314:Stress, Mechanical; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology
D016861:Cyclooxygenase Inhibitors; D011448:Prostaglandin Antagonists; D011453:Prostaglandins; D007052:Ibuprofen; D007213:Indomethacin