A Study of Some Effects of Streptozotocin Induced Diabetes Mellittus on the Visual Relay Centers (Lateral Geniculate Nucleus and Superior Colliculus) of the Adult Wistar Rats (Rattus Norvegicus)
This study joins others in trying to confirm some effects of streptozotocin induced diabetes mellitus on the visual relay centers in adult wistar rats. A total of 80 wistar rats of both sexes weighing 200g-220g were used and the rats were grouped into treatment and control groups. Diabetes was induced by intraperitoneal injection of streptozotocin (STZ) dissolved in 0.01 m citrate buffer at a dosage of 70mg/kg body weight. The control received an equivalent volume of 0.01m citrate buffer only. Biochemical activities of lactate dehydrogenase LDH for glycolytic pathway, glucose-6-phosphate dehydrogenase for pentose phosphate pathway and succinic dehydrogenase for Kreb’s cycle in the visual relay centers (LGN & SC) were assessed at post induction periods. Histological assessment of neurons in the lateral geniculate nucleus (LGN) and superior colliculus (SC) were carried out. Light microscopic examinations revealed deleterious effects of induced diabetes on the neurons of the lateral geniculate nucleus and superior colliculus. Gradual cell degeneration involving karyolysis and chromatolysis were observed. Numerous neuronophagic cells were also observed in association with the degenerating neurons. This study offers new evidence that streptozotocin induced diabetes mellitus causes deleterious effects in the pathways of carbohydrate metabolism in the lateral geniculate body and the superior colliculus and can be implicated as one of the factors responsible for visual loss experienced in diabetic conditions.