The Relationship Between Insulin Like Growth Factor-Ⅰ And Diabetic Peripheral Neuropathy In Rats

Objective To search for the relationship between insulin like growth factor-â… (IGF-â… ) and diabetic Peripheral Neuropathy (DPN), by detecting the expression of IGF-â… and protein kinase B (PKB, or Akt) in L5 dorsal root ganglion (DRG), and identifying whether there are apoptotic neurons in DRG in rats.Methods 1. Experimental diabetes model preparation Male Sprague-Dawley rats were randomly divided into two groups: diabetics (n=6) and weight-matched nondiabetic controls (n=10). Experimental diabetic models were induced by the intraperitoneal injection of streptozotocin (STZ) at a dose of 50mg/kg. At three days significantly hyperglycemic animals (random blood glucose > 16.7mmol/L) were considered diabetics. The untreated diabetics were maintained for 10 weeks. 2. Electrophysiology Motor nerve conduction velocity (MNCV) and the compound muscle action potential, Sensory nerve conduction velocity (SNCV) and the compound muscle action potential, minimum F-wave latency (minFLat) were measured on right sciatic nerve of both groups at 8 and 10 weeks. 3. Tissue preparation Before sacrificed, blood was harvested from heart for measuring glucose and glycosylated hemoglobin (HbA1c) level. And rats were sacrificed by intracardiac perfusion with physiological saline. Then the whole DRG and sciatic nerves were dissected free. Right sciatic nerve was examined by transmission electron microscope, and L5 DRG was used for immunohistochemical studies of...