Send to

Choose Destination
See comment in PubMed Commons below
J Physiol. 2002 Sep 1;543(Pt 2):691-8.

Combined inhibition of nitric oxide and prostaglandins reduces human skeletal muscle blood flow during exercise.

Author information

Department of Exercise Science, Concordia University, Montreal, Quebec, Canada.


The vascular endothelium is an important mediator of tissue vasodilatation, yet the role of the specific substances, nitric oxide (NO) and prostaglandins (PG), in mediating the large increases in muscle perfusion during exercise in humans is unclear. Quadriceps microvascular blood flow was quantified by near infrared spectroscopy and indocyanine green in six healthy humans during dynamic knee extension exercise with and without combined pharmacological inhibition of NO synthase (NOS) and PG by L-NAME and indomethacin, respectively. Microdialysis was applied to determine interstitial release of PG. Compared to control, combined blockade resulted in a 5- to 10-fold lower muscle interstitial PG level. During control incremental knee extension exercise, mean blood flow in the quadriceps muscles rose from 10 +/- 0.8 ml (100 ml tissue)(-1) min(-1) at rest to 124 +/- 19, 245 +/- 24, 329 +/- 24 and 312 +/- 25 ml (100 ml tissue)(-1) min(-1) at 15, 30, 45 and 60 W, respectively. During inhibition of NOS and PG, blood flow was reduced to 8 +/- 0.5 ml (100 ml tissue)(-1) min(-1) at rest, and 100 +/- 13, 163 +/- 21, 217 +/- 23 and 256 +/- 28 ml (100 ml tissue)(-1) min(-1) at 15, 30, 45 and 60 W, respectively (P < 0.05 vs. control). In conclusion, combined inhibition of NOS and PG reduced muscle blood flow during dynamic exercise in humans. These findings demonstrate an important synergistic role of NO and PG for skeletal muscle vasodilatation and hyperaemia during muscular contraction.

[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Wiley Icon for PubMed Central
    Loading ...
    Support Center