Catechol-O-methyltransferase in rat sensory ganglia and spinal cord.
The localization of catechol-O-methyltransferase immunoreactivity in rat dorsal root ganglia and in the spinal cord and its co-existence with substance P, calcitonin gene-related peptide and fluoride-resistant acid phosphatase in dorsal root ganglion cells was examined with immunohistochemical and histochemical double-staining methods. Analysis of dorsal of dorsal root ganglia at both cervical and lumbar levels revealed catechol-O-methyltransferase immunoreactivity in numerous dorsal root ganglion cells. Double-staining studies showed that catechol-O-methyltransferase and substance P immunoreactivities were located in different cells with a few exceptions, whereas both catechol-O-methyltransferase and calcitonin gene-related peptide immunoreactivities were detected in about 10% of all labeled cells positive for one of the two markers at both levels studied. The great majority of fluoride-resistant alkaline phosphatase-positive cells were also immunoreactive for catechol-O-methyltransferase. Again, no difference was found between cervical and lumbar levels. Catechol-O-methyltransferase immunoreactivity was also found in the neuropil of the dorsal horn of the spinal cord. The staining was most intense in the superficial laminae (I-III) and overlapped partly with substance P and calcitonin gene-related peptide immunoreactivity. Western blotting analysis revealed that soluble catechol-O-methyltransferase was the clearly dominating form of the enzyme in dorsal root ganglia. The distribution pattern of catechol-O-methyltransferase in dorsal horn and sensory neurons suggests that the enzyme may modulate sensory neurotransmission.
Karhunen
T
T
Department of Biology, Abo Akademi University, Turku, Finland.
Ulmanen
I
I
Panula
P
P
D000135:Acid Phosphatase / Q000378:metabolism; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D002394:Catechol O-Methyltransferase / Q000378:metabolism*; D017950:Ganglia, Sensory / Q000201:enzymology* / Q000648:ultrastructure; D005727:Ganglia, Spinal / Q000201:enzymology* / Q000648:ultrastructure; D007150:Immunohistochemistry; D008297:Male; D016253:Microscopy, Immunoelectron; D051381:Rats; D017208:Rats, Wistar; D013373:Substance P / Q000378:metabolism
D013373:Substance P; D002394:Catechol O-Methyltransferase; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D015740:Calcitonin Gene-Related Peptide