CALCITONIN-GENE-RELATED PEPTIDE-LIKE AND SUBSTANCE P-LIKE IMMUNOREACTIVE FIBERS IN THE SPERMATIC NERVE AND TESTIS OF THE DOG

In order to determine if calcitonin gene-related peptide (CGRP) and su bstance P (SP) coexist in peripheral spermatic nerve fibers, we carrie d out a double-staining immunofluorescence study using confocal micros copy and fluorescence microscopy. CGRP-and SP-like immunoreactivity (L I) coexisted in the spermatic nerve trunk and in the single fibers run ning along the surface of the testis. The great majority of the SP-con taining fibers also held CGRP-LI, although some fibers contained CGRP- LI without SP-LI. These observations are consistent with previous obse rvations on testicular dorsal root ganglion neurons. Additionally, we carried out an immunogold silver staining for CGRP and found CGRP-cont aining nerve bundles, single nerve fibers and their nerve terminals. S ome CGRP-containing nerve terminals were located very superficially in the tunica albuginea (<5 mu m from the surface). (C) 1997 Elsevier Sc ience Ireland Ltd.