Immunohistochemical localization of 5-hydroxytryptamine, histamine and histidine decarboxylase in the rat major pelvic and coeliac-superior mesenteric ganglion.
The localization of 5-hydroxytryptamine (5-HT), histamine and histidine decarboxylase (HDC), the enzyme synthesizing histamine, was studied in the rat major pelvic and coeliac-superior mesenteric ganglia by an indirect immunofluorescence technique. Small cells (10-20 microns in diameter) exhibiting 5-HT, histamine or HDC immunoreactivities were observed in clusters or occurred as solitary cells in both ganglia. In the major pelvic ganglia, solitary histamine-immunoreactive principal neurons were also observed. Colocalization studies indicated that all 5-HT-, histamine- and HDC-immunoreactive small cells in these ganglia were labelled with tyrosine hydroxylase (TH), suggesting that they are small intensely fluorescent (SIF) cells. In the coeliac-superior mesenteric ganglia, all TH-immunoreactive SIF cells were also intensely immunoreactive for 5-HT and HDC. In the major pelvic ganglia, all TH-immunoreactive SIF cells contained 5-HT immunoreactivity, and the majority of them were also intensely immunoreactive for HDC. In both ganglia, however, only a subpopulation of TH-immunoreactive SIF cells displayed histamine immunoreactivity. The results indicate that in the rat major pelvic and coeliac-superior mesenteric ganglia, a population of catecholamine-containing SIF cells contain 5-HT and histamine suggesting a diverse role SIF cells may have in so far as modulation of ganglion transmission is concerned.
Karhula
T
T
Department of Anatomy, University of Helsinki, Finland.
Panula
P
P
Steinbusch
H
H
Häppölä
O
O
D000818:Animals; D005728:Ganglia, Sympathetic / Q000378:metabolism*; D006636:Histamine Release; D006640:Histidine Decarboxylase / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*; D014018:Tissue Distribution
D012701:Serotonin; D006640:Histidine Decarboxylase