Possible role of the histaminergic system in autonomic and cardiovascular responses to neuropeptide Y.
Previous studies have demonstrated that neuropeptide Y (NPY) affects blood pressure (BP) in anesthetized rats. Here, we examined the effects of the third cerebral ventricular (3CV) injection of various doses of NPY on renal sympathetic nerve activity (RSNA) and BP in anesthetized rats. 3CV injection of NPY suppressed RSNA and BP in a dose-dependent manner. Moreover, suppressing effects of NPY on RSNA and BP were eliminated by lateral cerebral ventricular (LCV) preinjection of thioperamide, an antagonist of histaminergic H3-receptor, not diphenhydramine, an antagonist of histaminergic H1-receptor. In addition, 3CV injection of NPY accelerated gastric vagal nerve activity (GVNA) and inhibited brown adipose tissue sympathetic nerve activity (BAT-SNA) of anesthetized rats, and lowered brown adipose tissue temperature (BAT-T) of conscious rats. Thus, these evidences suggest that central NPY affects autonomic nerves containing RSNA, GVNA or BAT-SNA, and BP by mediating central histaminergic H3-receptors.
Tanida
Mamoru
M
Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577, Japan. mtanida@sk.ritsumei.ac.jp
Shen
Jiao
J
Nagai
Katsuya
K
D002001:Adipose Tissue, Brown / Q000187:drug effects / Q000378:metabolism; D000320:Adrenergic Fibers / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D004155:Diphenhydramine / Q000378:metabolism / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects*; D006634:Histamine H1 Antagonists / Q000378:metabolism / Q000494:pharmacology; D054828:Histamine H3 Antagonists / Q000378:metabolism / Q000494:pharmacology; D007276:Injections, Intraventricular; D008297:Male; D009478:Neuropeptide Y / Q000378:metabolism / Q000494:pharmacology*; D010880:Piperidines / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013686:Telemetry
D006634:Histamine H1 Antagonists; D054828:Histamine H3 Antagonists; D009478:Neuropeptide Y; D010880:Piperidines; D004155:Diphenhydramine; C052075:thioperamide