Fig. 2. nNOS mRNA level in the spinal cord and DRG of allodynic rats after L5/6 spinal nerve ligation and diabetic neuropathy. Total RNA was extracted from the spinal cord and DRG of Harlan Sprague Dawley rats with allodynia resulting from tight ligation of the left L5/6 spinal nerves (2 weeks) or diabetes (8 weeks). nNOS mRNA was detected by RNase protection assays. A,Representative autoradiograms. Twenty micrograms of total RNA from the spinal cord or total RNA from two (L4, L5/6, and diabetic) or three (L1) DRGs were used for each lane. nNOS bands had a longer exposure time than did cyclophilin bands because of the low abundance of the nNOS mRNA, except for the separate RNase protection of diabetic samples in which lower specific activity of the cyclophilin probe was used. Lanes are labeled 1, for the contralateral side or nondiabetic rats, and 2, for the nerve-ligated side or diabetic neuropathy rats. B,Percentage change of nNOS mRNA in neuropathic tissues compared with control tissues. Data are presented as the means ± SEM from 6 to 10 rats except for the L5/6 DRG samples that are from 4 rats (*p < 0.05 by Student's t test or Mann–Whitney test). Cyclo., Cyclophilin;Diabet., diabetic; Dors., dorsal;Lumb.S.C., lumbar spinal cord; Vent., ventral.