Morphologic Comparison of Peripheral Nerves in Adipocyte Tissue from db/db Diabetic versus Normal Mice

Present study investigated the morphologic changes of autonomic nerves in the adipose tissue in diabetic animal model. Male obese type 2 diabetic db/db mice and age matched non-diabetic db/m control mice were used. Epididymal adipose tissue from diabetic db/db mice with that from control heterozygous db/m mice was compared using confocal microscopy-based method to visualize intact whole adipose tissue. Immunohistochemistry with tyrosine hydroxylase for sympathetic (SP), choline acetyltransferase for parasympathetic (PSP), and protein gene product 9.5 (PGP 9.5) for whole autonomic nerves was performed. The quantity of immunostained portion of SP, PSP, and PGP 9.5 stained nerve fibers showed decreased trend in diabetic group; however, the ratio of SP/PSP of adipose tissue was higher in diabetic group compared with control group as follows (0.70±0.30 vs. 0.95±0.25, P<0.05; normal vs. diabetic, respectively). Both SP and PSP nerve fibers were observed in white adipose tissue and PSP nerve fibers were suggested as more decreased in diabetes based on our observation.