Histamine acts directly on calcitonin gene-related peptide- and substance P-containing trigeminal ganglion neurons as assessed by calcium influx and immunocytochemistry.
Primary cultures of rat trigeminal ganglion cells were exposed to histamine, and the intracellular free-calcium concentration, [Ca2+]i, was measured by the calcium-sensitive dye fura-2. Histamine increased the [Ca2+]i of the neurons. Pretreatment of the cells with histamine H1-receptor blocker, or removal of extracellular calcium, abolished the response, however, the response was not altered by pretreatment with H2-blocker. Immunocytochemical analysis showed that these cultured cells that responded to histamine identically showed substance P- or calcitonin gene-related peptide-like immunoreactivity.
Department of Otolaryngology, Kumamoto University, School of Medicine, Japan.
E
E
Tani
S
S
Shiosaka
M
M
Sato
T
T
Ishikawa
M
M
Tohyama
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism*; D002118:Calcium / Q000493:pharmacokinetics*; D002478:Cells, Cultured; D002927:Cimetidine / Q000494:pharmacology; D016257:Fura-2; D006632:Histamine / Q000494:pharmacology*; D007150:Immunohistochemistry; D011738:Pyrilamine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011968:Receptors, Histamine / Q000187:drug effects / Q000502:physiology*; D013373:Substance P / Q000378:metabolism*; D012668:Trigeminal Ganglion / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*
D011968:Receptors, Histamine; D013373:Substance P; D002927:Cimetidine; D006632:Histamine; D011738:Pyrilamine; D015740:Calcitonin Gene-Related Peptide; D002118:Calcium; D016257:Fura-2