Fig. 1. Changes in renal tissue levels of calcitonin gene-related peptide (CGRP) in rats subjected to renal ischemia/reperfusion (I/R), and effect of capsazepine (CPZ) and denervation of primary sensory nerves on renal I/R-induced increases in renal tissue CGRP levels at 1 h after I/R. ( A ) CGRP were determined at the indicated time points after 45 min of I/R (solid circles), or sham-operated animals (without I/R, open circles). Renal levels of CGRP began to increase and reached a peak level at 1 h after I/R. The values observed in rats subjected to I/R were higher than those in sham-operated rats. Data are expressed as mean ± SD values of six animals. * P < 0.05 versus preischemia level; † P < 0.05 versus sham-operated group. ( B ) CPZ was administered subcutaneously 30 min before renal ischemia. Denervation of primary sensory nerves was accomplished by high-dose capsaicin. Data are expressed as mean ± SD values of six animals. * P < 0.05 versus sham-operated group; † P < 0.05 versus vehicle-treated group.