Histamine-induced inositol phosphate accumulation in type-2 astrocytes.
Histamine elicited dose-dependent accumulation of [3H]inositol phosphates in type-2 astrocytes, but not in type-1 astrocytes. The ED50 was about 2.4 x 10(-6) M and the maximal response was obtained at 10(-4) M. This response was dose-dependently inhibited by H1-antagonists, mepyramine and D- and L-chlorpheniramine. Furthermore, D- and L-chlorpheniramine showed stereoselectivity in the inhibition. On the other hand, an H2-antagonist, famotidine, and an H3-antagonist, thioperamide, did not inhibit the response. These results indicate that histamine stimulates accumulation of inositol phosphates in type-2 astrocytes via H1-receptors.
Kondou
H
H
Department of Pharmacology II, Faculty of Medicine, Osaka University, Suita, Japan.
Inagaki
N
N
Fukui
H
H
Koyama
Y
Y
Kanamura
A
A
Wada
H
H
D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism*; D002478:Cells, Cultured; D002744:Chlorpheniramine / Q000494:pharmacology; D015738:Famotidine / Q000494:pharmacology; D006632:Histamine / Q000494:pharmacology*; D007295:Inositol Phosphates / Q000378:metabolism*; D010880:Piperidines / Q000494:pharmacology; D011738:Pyrilamine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011968:Receptors, Histamine / Q000378:metabolism
D007295:Inositol Phosphates; D010880:Piperidines; D011968:Receptors, Histamine; D002744:Chlorpheniramine; D015738:Famotidine; D006632:Histamine; D011738:Pyrilamine; C052075:thioperamide