Anterograde and retrograde axonal transport of 6-phosphofructokinase activity in the rat sciatic nerve

Optimal conditions for the measurement of phosphofructokinase activity in segments of rat sciatic nerve were established. It was found that maximal activity was obtained when the Triton X-100 concentration of the extraction buffer was 1% (v:v). Nerve segments could be stored at ?80°C for at least 1 week without measurable loss of activity. The femoral portion of the sciatic nerve showed no proximo-distal bias in the distribution of phosphofructokinase activity and there were no differences in the activities of anatomically equivalent segments from contralateral nerves. Phosphofructokinase activity was subject to both anterograde and retrograde axonal transport as indicated by accumulation on both sides of a constriction applied to the sciatic trunk. Accumulation was progressive and appeared to be linear with time for at least 24 h. Linearity was lost at constrictions applied for 48 h. In experiments in which synchronous double ligations were applied to the nerve (9 mm apart), there was no redistribution of phosphofructokinase activity in the segment of nerve isolated between the two constrictions.