Spinal Cord Lipid and ATPase Changes in Zucker Diabetic Fatty (ZDF) Rats, a Model of Type 2 Diabetes

Background/Objectives: Altered lipid metabolism is a key feature of type 2 diabetes mellitus (T2DM), yet its impact on early spinal cord involvement remains poorly understood. Distinguishing between pathological lipid accumulation and adaptive metabolic responses is essential for interpreting initial stages of neural alteration in T2DM. This study aimed to characterize spinal cord lipid composition and ATPase activities in a rat model of T2DM. Methods: Zucker diabetic fatty (ZDF) rats were used as a model of T2DM and divided into diabetic and obese groups, with lean Zucker rats as controls. ATPase activities in spinal cord tissue were measured spectrophotometrically, and lipid profiling was performed using gas chromatography with flame-ionization detection. Indices of stearoyl-CoA desaturase-1 (SCD1) and delta-5 desaturase activity (D5D) were calculated from specific fatty acid ratios as estimates of enzyme-related activity. Results: Diabetic rats exhibited significantly higher levels of free monounsaturated fatty acids (MUFAs) compared with controls, while the obese group showed a moderate increase. Elevated SCD1 indices were indicative of increased estimated MUFA synthesis. Levels of free polyunsaturated fatty acids (PUFAs), including those crucial for myelin stability, as well as ATPase activities, remained unchanged, suggesting preserved basal membrane-associated enzyme function. Conclusions: This study identifies lipid alterations in the spinal cord preceding overt neurodegenerative changes in T2DM, characterized by increased free MUFA abundance, without evidence of altered ATPase activities. These findings support the interpretation that lipid changes observed at this stage are more consistent with adaptive metabolic remodeling than with overt structural or functional neural impairment.