Regional blood flow in transected rat spinal cord during hypothermia

Regional blood flow (RBF) increases in the spinal cord and sciatic nerve of acutely hypothermic rats. To determine whether cord transection affects this response, we measured RBF in rat spinal cord and sciatic nerve 2 h after cord transection at vertebrae T8 (n = 18 rats) and T11 (n = 18 rats) using [14C]butanol distribution. Nine in each group were normothermic controls. In T11 transection-hypothermia (25-27 degrees C rectal temperature), RBF increased in the three rostral cord segments by 28-40% (P less than 0.05); caudally, cord RBF was depressed in two segments (P less than 0.05), unchanged in the other; RBF fell in nerve (P less than 0.05). In T8 transection-hypothermia, RBF was unchanged in the two rostral cord segments; caudally, RBF was depressed in one cord segment (P less than 0.05) and unchanged in the others; RBF was unchanged in nerve. We conclude that RBF does not rise in caudal spinal cord segments or in sciatic nerve during hypothermia in rats with prior spinal cord transection.