Colchicine enhances mRNAs encoding the precursor of calcitonin gene-related peptide in brainstem motoneurons.
Hybridization signals indicating mRNAs encoding the precursor of calcitonin gene-related peptide (CGRP) and CGRP immunoreactivity were detected on parallel sections containing brainstem motor nuclei using in situ hybridization histochemistry and immunohistochemistry. In untreated and saline-injected rats the motoneurons in the hypoglossal, facial motor nuclei and in the ambiguus nucleus showed weak to moderate hybridization signals. In these motoneurons CGRP immunoreactivity was restricted to the Nissl bodies of the perikarya. Twenty-four and 42 hours after intracerebroventricular colchicine injection the intensity of both the hybridization signal and the immunoreaction product increased. The distribution of CGRP immunoreactivity changed from discrete perikaryal localization to diffuse reaction in the perikarya and along the proximal dendritic tree. Motoneurons in the rest of the brainstem motor nuclei (VIth, Vth, IVth and IIIrd) of untreated and saline-injected rats showed neither hybridization signal nor CGRP immunoreactivity. After intracerebroventricular injection of colchicine these motoneurons showed both hybridization signal and CGRP immunoreactivity. In all nuclei the size of motoneurons decreased and their Nissl structure changed to an amorphous basophilic mass following colchicine treatment.
Réthelyi
M
M
Department of Physiology, University of North Carolina, Chapel Hill.
Mohapatra
N K
NK
Metz
C B
CB
Petrusz
P
P
Lund
P K
PK
D000818:Animals; D001483:Base Sequence; D001933:Brain Stem / Q000187:drug effects / Q000378:metabolism*; D015740:Calcitonin Gene-Related Peptide / Q000096:biosynthesis*; D003078:Colchicine / Q000008:administration & dosage / Q000494:pharmacology*; D006651:Histocytochemistry; D007150:Immunohistochemistry; D007276:Injections, Intraventricular; D008297:Male; D008969:Molecular Sequence Data; D009046:Motor Neurons / Q000187:drug effects / Q000378:metabolism*; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012012:Red Nucleus / Q000166:cytology / Q000378:metabolism; D013194:Staining and Labeling
D012333:RNA, Messenger; D015740:Calcitonin Gene-Related Peptide; D003078:Colchicine