Figure 1. SNI up-regulated Cox2 and Pgis mRNA in the ipsilateral spinal cord. A, Semiquantitative RT-PCR analysis showed Cox2, Pgis, and IP receptor mRNA expression in the L4-L5 ipsilateral spinal cord taken from rats at 0 (naive), 12, 18, 24, 48, and 72 h after nerve injury. GAPDH was used as the loading control. B, Quantification of the relative mRNA levels of Cox2, Pgis, and IP receptor mRNA. The data were first normalized to GAPDH and then expressed as fold change compared with the naive rat spinal cord (n = 5, mean ± SE; *, p < 0.05; **, p < 0.001, Fisher’s PLSD). C–K, ISHH images of the spinal cord. Dark-field images of ISHH revealed mRNA distribution of Cox2 (C), Pgis (F), and IP receptor (I) after peripheral nerve injury in the L4–5 spinal cord. Scale bar: (C, F) 500 µm, (I) 100 µm. Higher-magnification photographs from hematoxylin and eosin–counterstained sections under bright-field illumination in the ipsilateral dorsal horn for Cox2 (D), Pgis (G), and IP receptor (J) of naive rats or 2 d after nerve injury. Arrowheads indicate positive cells. Scale bar: 20 µm. E, Bright-field photomicrographs showed combined ISHH for Cox2 mRNA with immunostaining of NeuN, GFAP, Iba1, and PECAM1. H, Pgis mRNA with immunostaining of NeuN, GFAP, Iba1, PECAM1, and COX2. K, IP receptor mRNA with immunostaining of NeuN, GFAP, and Iba1, counterstained with hematoxylin, in the dorsal horn 2 d after nerve injury. Open arrowheads indicate single immunostained cells (brown staining). Black arrowheads indicate cells single-labeled with ISHH (aggregation of grains). Open arrows indicate cells double-labeled with ISHH and IHC. Scale bar: 20 µm. 2 d: 2 days (48 h) after surgery. Ipsi, ipsilateral side; contra, contralateral side.