Quantitative analysis of gastrocnemius metabolites with 1H-MRS for early evaluation on diabetic peripheral neuropathy in diabetic rat models / 中国医学影像技术

ABSTRACT

Objective: To explore the value of quantitative analysis of gastrocnemius metabolites with 1H-MRS for early evaluation on diabetic peripheral neuropathy in diabetic rat models. Methods: Totally 40 male SD rats were randomly divided into experimental group and normal group (each n=20). In experimental group, diabetes models were established by feeding with high sugar and high-fat fed diet and streptozotocin injection. The right gastrocnemius 1H-MRS of 2 groups were collected before modeling as well as 7 days, 14 days and 21 days after modeling. The concentration values of choline-containing compounds (Cho), creatine compounds (Cr), intra-myocellular lipids (IMCL), Cho/Cr and IMCL/Cr were obtained. The rats in normal group were fed with general diet. Electrophysiological and pathological examinations were performed 21 days after modeling, the motor nerve conduction velocity (MNCV) and sensory nerve conduction velocity (SNCV) of right sciatic nerve were measured. The metabolite concentration values at each time point in experimental group were compared, and MNCV and SNCV were compared between groups. The pathological results of 2 groups were observed. Results: There were differences of values of Cho, Cho/Cr, Cr, IMCI, IMCI/Cr in experimental group at different time points (F=6.69, 5.41, 3.65, 3.51, 3.10, all P<0.05). Cho and Cr values 14 days and 21 days after modeling were higher than those before modeling (both P<0.05), and IMCL values 7 days after modeling were higher than those before modeling (P<0.05). MNCV and SNCV of the right sciatic nerve in experimental group were slower than those in normal group 21 days after modeling (t=2.74, 4.62, both P<0.05). Compared with normal group, the nerve fibers in experimental group were sparse, loose and disordered, some myelin sheaths were stained lightly and unevenly and axons became thin and atrophic. Conclusion: 1H-MRS can be used for noninvasive quantitative analysis of skeletal metabolites, so as for early evaluation of DPN in rat diabetic models.