DIFFERENT REINNERVATION PATTERNS IN THE CELIAC MESENTERIC AND SUPERIOR CERVICAL-GANGLIA FOLLOWING GUANETHIDINE SYMPATHECTOMY IN ADULT-RATS/

We sought to determine whether chronic guanethidine (Gu) treatment in adult rats produces depletion of sympathetic neurons and hyperinnervat ion by sensory neuropeptides in the celiac/superior mesenteric (C/SMG) ganglion. Rats received. du 40 mg/kg per day i.p or saline for 5 week s. Upon completion of treatment, the C/SMG and the superior cervical g anglion (SCG) were examined for neuropeptide Y (NPY), substance P (SP) , calcitonin gene-related peptide (CGRP) and vasoactive intestinal pol ypeptide (VIP), both by immunocytochemistry (ICC) and radioimmunoassay (RIA). Gu produced marked depletion of NPY-containing neurons and NPY content in the C/SMG, similar to that in the SCG (- 89 +/- 2 vs. - 92 +/- 4%, respectively). SP and CGRP immunoreactivities were significan tly higher in control C/SMG as compared with SCG; after Gu treatment, there was no significant increase in either SP or CGRP in the C/SMG, h owever, both increased in the SCG. In contrast, VIP levels were simila r in the SCG and C/SMG in controls and increased in the C/SMG but not in the SCG after Gu treatment. Thus, in adult rats, the C/SMG is as su sceptible as the SCG to Gu treatment; the different pattern of hyperin nervation by SP, CGRP and VIP of the C/SMG as compared with the SCG ma y reflect the different sources for these neuropeptides in prevertebra l as compared with paravertebral ganglia.