Glucose and leucine uptake in the hypoglossal nucleus after hypoglossal nerve transection with and without prevented regeneration in the Sprague-Dawley rat.

We studied [14C]2-deoxyglucose and [14C]leucine uptake in the rat hypoglossal nucleus after hypoglossal nerve transection and when regeneration was prevented by placing a nylon ligature around the nerve proximal to the cut. Glucose and leucine uptake increased after nerve transection in both the animals with nerve transection alone and with the ligature. Both the glucose and leucine uptake increased more in animals with the ligature. The glucose and leucine uptakes returned to normal at 30 and 45 days, respectively, after transection alone and at 60 days in animals in whom regeneration was prevented with a ligature. This suggests that there is a more powerful stimulus to regeneration when regeneration is prevented but that some mechanism turns the process off after a fixed time.