Centrally administered histamine evokes the adrenal secretion of noradrenaline and adrenaline by brain cyclooxygenase-1- and thromboxane A2-mediated mechanisms in rats.
Plasma adrenaline is originated from adrenal medulla, while plasma noradrenaline reflects the release from sympathetic nerves in addition to the secretion from adrenal medulla. The present study was designed to characterize the source of plasma catecholamines induced by centrally administered histamine, with regard to the brain prostanoids. Intracerebroventricularly (i.c.v.) administered histamine (1, 5 and 10 microg/animal) elevated plasma noradrenaline and adrenaline (noradrenaline<adrenaline) in a dose-dependent manner. Ketoprofen (a selective inhibitor of cyclooxygenase-1) (100, 250 and 500 microg/animal, i.c.v.) dose-dependently reduced the histamine (5 microg/animal, i.c.v.)-induced elevation of both catecholamines, while NS-398 (a selective inhibitor of cyclooxygenase-2) (250 and 500 microg/animal, i.c.v.) had no effect. The histamine-induced response was dose-dependently attenuated by furegurelate (an inhibitor of thromboxane A(2) synthase) (250 and 500 microg/animal, i.c.v.), and abolished by acute bilateral adrenalectomy. These results suggest that centrally administered histamine evokes plasma noradrenaline and adrenaline from adrenal medulla by brain cyclooxygenase-1- and thromboxane A(2)-mediated mechanisms in rats.
Shimizu
Takahiro
T
Department of Pharmacology, Graduate School of Medicine, Kochi University, Nankoku, Japan. shimizu@med.kochi-u.ac.jp
Okada
Shoshiro
S
Yamaguchi
Naoko
N
Sasaki
Tsuyoshi
T
Lu
Lianyi
L
Yokotani
Kunihiko
K
D000313:Adrenal Medulla / Q000378:metabolism*; D000315:Adrenalectomy; D000818:Animals; D001572:Benzofurans / Q000494:pharmacology; D001921:Brain / Q000187:drug effects* / Q000201:enzymology; D051545:Cyclooxygenase 1 / Q000378:metabolism*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004837:Epinephrine / Q000097:blood*; D006632:Histamine / Q000494:pharmacology*; D018494:Histamine Agents / Q000494:pharmacology*; D007276:Injections, Intraventricular; D007660:Ketoprofen / Q000494:pharmacology; D008297:Male; D009578:Nitrobenzenes / Q000494:pharmacology; D009638:Norepinephrine / Q000097:blood*; D051381:Rats; D017208:Rats, Wistar; D013449:Sulfonamides / Q000494:pharmacology; D013928:Thromboxane A2 / Q000037:antagonists & inhibitors / Q000378:metabolism*
D001572:Benzofurans; D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D018494:Histamine Agents; D009578:Nitrobenzenes; D013449:Sulfonamides; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D013928:Thromboxane A2; D006632:Histamine; D007660:Ketoprofen; D051545:Cyclooxygenase 1; C039936:furegrelate; D009638:Norepinephrine; D004837:Epinephrine