Histopathological Changes in a Rat Model of Diabetic Neuropathy Hanan Kumar Gopalan

Kumar Gopalan, Hanan

	Histopathological Changes in a Rat Model of Diabetic Neuropathy Hanan Kumar Gopalan
Al-Anbar Journal of Veterinary Sciences
Volume 17, Issue 1, August 2024, Pages 59-65 PDF (719.85 K)
Author
Hanan Kumar Gopalan
University Kuala Lumpur, Institute of Medical Science Technology, Clinical & Biomedical Laboratory Science, 43000 Kajang, Selangor, Malaysia
Abstract
This study has been done to investigate the histopathological changes in a rat model of diabetic neuropathy. The 24 male rats used in this research, were splinted randomly into two groups of 12 animals each. The first group (G1; consisted of healthy control rats), was administered with normal saline, while the second group (G2; STZ treated animals) received a single intraperitoneal injection of freshly prepared streptozotocin (STZ), at a dosage of 60 mg/kg, to induce a diabetes-like state in the rats. At the third day after STZ injection, a digital glucometer was used to measure blood glucose levels of 12-hour fasting rats; the hyperglycemia state was considered if the fasting blood glucose level (FBG) was greater than 250 mg/dl. To assess neuropathic pain, cold allodynia was calculated by counting some times the foot withdrawal occurred in response to cold stimuli applied to the back of the hand. The sciatic nerve was carefully removed when rats were sacrificed (after 2 months) and preserved in 10% formalin for histopathological investigations. Normal blood glucose levels were maintained in the control rats throughout the study. However, G2 exhibited much greater FBG levels than healthy animals. In the 2-month study period, the G2 maintained FBG levels above 250 mg/dl. The score for the severity of STZ on sciatic nerves showed a significant difference between the STZ-treated group (G2) as compared to non-treated (G1). No paw reactions were seen when intact animals were subjected to plantar surface acetone. The experimental groups did not show any notable reactions to acetone on the tenth day after the diagnosis of diabetes. On days 20, 30, 40, 50 and 60 after diabetes confirmation, there were significant differences in paw withdrawal frequency between the G1 and G2 (p<0.001). Within the control group, nerve fibres were found to be regularly arranged and there was no evidence of axonal swelling. However, in the G2 animals, nerve fibres were found to be significantly disorganized, and there was a notable increase in the number of Schwann cells in the sciatic nerves, suggesting damage, in comparison to the control group. In conclusion, the present study confirmed different neuropathic effects on sciatic nerves in rat models of diabetic neuropathy. In addition, the histopathological changes of the nerves, including severe lipoid degeneration of axons, could be related to the chronic hyperglycemic state or to the toxicity of STZ on the peripheral nervous system, which requires further investigation.
Keywords
Histopathology; Rat; Diabetes; Neuropathy

Statistics Article View: 51 PDF Download: 14