Neuroelectrophysiological abnormalities are related to metabolic and advanced non-enzymatic glycation changes in prospectively evaluated diabetic Sprague-Dawley rats

In order to sequentially explore central (CNS) and peripheral (PNS) nervous system abnormalities in experimental diabetes mellitus, neuroelectrophysiological and nervous protein biochemical changes were investigated in streptozotocin diabetic Sprague-Dawley rats after 1.5, 3, 6 and 12 months from induction of diabetes. Visual (VEP), brainstem-auditory (BAEP) and somatosensory (SEP) evoked potentials were evaluated in control and diabetic rats. Advanced glycation end-product (AGE) levels were measured by spectrofluorimetry in protein extracts from central and peripheral nervous tissue samples. Mean VEP (P1 wave) and BAEP (waves I, II and III) latencies were increased whereas SEP (Tarsus-L6, L6-Cortex and T6-Cortex) conduction/propagation velocities were reduced in diabetic rats at all times (p< 0.05 to p< 0.0001), the alterations being already present after 1.5 months from