CHRONIC EXPERIMENTAL DIABETES MELLITUS

Background: Multiple factors operate in the development of diabetic neuropathy.Sensory neurons are not protected by blood-brain or blood-nerve barrier; also the dorsal rootganglion cells (DRG) have a higher metabolic requirement than the nerve trunks. Oxygen levelat the dorsal root ganglions also appears to be lower. All these physiological characteristicssuggest that DRG may be particularly susceptible to damage in prolonged diabetic conditions.Objectives: To observe the quantitative cellular changes in dorsal root ganglion cells in rats withprolonged experimental diabetes. Study Design: An experimental study. Setting: Departmentof Human Anatomy, Faculty of Medicine, Umm al Qura University, Makkah, Saudi Arabia.Period: Fifteen months to complete. Material and methods: Observations were made on sixcontrol and six streptozotocin-treated male Sprague-Dawley rats after 12 months of diabetes.Cell count was done on silver-stained paraffin sections. DRG cells were arbitrarily groupedas large A-type and small B-type. Statistical examination of the cell count was done using atwo-tailed t-test. Values were considered significant at P ≤ 0.05. Results: In the control groupof animals the mean total number was 15856.33 ± 552.538 while in the diabetic animals itwas 11836.666 ±583.177; the reduction in the number of cells was significant. The number ofA-type and B-type cells and their percentages in the control group and the diabetic group ofanimals were 2753.833±257.683 (17.36%), 13102.5±443.092 (82.63%) and 1202.833±87.082(10.16%), 10633.833±517.900 (89.83%) respectively. The differences in the number of A-typeand B-type of cells when compared between control and diabetic groups of animals werestatistically highly significant. Conclusion: Selective cells damage to DRG cells may be theharbinger of diabetic neuropathy in experimentally induced diabetic rats.