The presence of heme-oxygenase and biliverdin reductase in human cranial ganglia indicates a role for carbon monoxide in neural transmission.
OBJECTIVE
The purpose of this study was to localize in cranial ganglia of man the occurrence of the putative gaseous neural messenger carbon monoxide (CO) and the biliverdin degrading enzyme biliverdin reductase (BVR).


METHODS
Immunocytochemistry with antibodies against the CO-inducing enzymes HO-1, HO-2, BVR and calcitonin gene-related peptide was used.


RESULTS
In the trigeminal ganglion about 60% of the cell bodies exhibited HO-2- and about 40% BVR-immunoreactivity. HO-2- as well as BVR-immunoreactivity was predominantly (78%) expressed in medium-sized cells (30-60 microm). In the superior cervical ganglion about 40% of the cell bodies exhibited HO-2-immunoreactivity. In the sphenopalatine and otic ganglia only a few cell bodies were HO-2 immunoreactive. HO-1, the inducible isoform of heme oxygenase, gave only very weak immunoreactivity in all ganglia examined. Double immunostaining revealed that in the human trigeminal ganglion HO-2 and BVR co-localized with calcitonin gene-related peptide.


CONCLUSIONS
The finding suggests that CO might serve as a modulator of synaptic transmission in man.
Uddman
Rolf
R
Department of Otorhinolaryngology, Malmö University Hospital, Malmö, Sweden. Rolf.Uddman@oron.mas.lu.se
Tajti
Janos
J
Sundler
Frank
F
Cardell
Lars-Olaf
LO
D000368:Aged; D000369:Aged, 80 and over; D002248:Carbon Monoxide / Q000378:metabolism*; D005726:Ganglia, Parasympathetic / Q000378:metabolism; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism*; D051547:Heme Oxygenase-1; D006801:Humans; D007150:Immunohistochemistry; D008565:Membrane Proteins; D008875:Middle Aged; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000378:metabolism*; D017783:Superior Cervical Ganglion / Q000378:metabolism; D009435:Synaptic Transmission / Q000502:physiology*; D012668:Trigeminal Ganglion / Q000378:metabolism*
D008565:Membrane Proteins; D002248:Carbon Monoxide; C496541:HMOX1 protein, human; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; C105245:heme oxygenase-2; D044925:Oxidoreductases Acting on CH-CH Group Donors; C019789:biliverdin reductase