Impaired orthograde axonal transport in acute hypoglycaemia, an effect mediated via hypothermia

The effect of hypoglycaemia (blood glucose 1 mmol/l) on the axonal transport of acetylcholinesterase activity and noradrenaline was examined in non-diabetic rats. Rats were made hypoglycaemic over a 6-h period during which acetylcholinesterase and noradrenaline accumulated proximal to a tight ligature applied to the left sciatic nerve. The hypoglycaemic rats were either kept at room temperature, when they became profoundly hypothermic, or kept in a 31 degrees C incubator to maintain body temperature as close to normal as possible. Hypoglycaemia without temperature control caused marked reductions in the accumulation of acetylcholinesterase activity and of noradrenaline proximal to the ligature. These accumulation deficits were obviated by body heating. The findings indicate that hypoglycaemia impairs fast orthograde axonal transport, but that this effect is a consequence of hypothermia rather than glucopenia.