The effect of stimulation frequency on intact muscle blood flow was measure
d by radiolabelled microsphere entrapment. Maximum flow occurred at 4 Hz in
both extensor digitorum longus and tibialis anterior (156 +/- 13 and 205 /- 24 ml min(-1) (100 g)(-1), respectively). Regional differences in fibre
composition were reflected in the relative flow rates, with functional hype
raemia in the oxidative tibialis anterior core being twice that of the glyc
olytic cortex at 10 Hz. A consistent difference in flow between legs was no
ted that may originate from an unequal division of the common iliac artery
in rats.