Histamine-induced, central nervous system-mediated hyperglycemia is suppressed by atropine in the brain.
We investigated the relationship between histamine and muscarinic cholinergic neurons in central nervous system (CNS)-mediated glucose regulation in anesthetized fed rats. The injection of pyrilamine (5 x 10(-7) mol) into the third cerebral ventricle suppressed the hyperglycemia induced by intraventricular injection of histamine (5 x 10(-7) mol). Ranitidine (5 x 10(-7) mol), however, did not suppress this hyperglycemia. The injection of atropine (5 x 10(-9)-5 x 10(-7) mol) into the third cerebral ventricle suppressed the histamine-induced hyperglycemia in a dose-dependent manner. These findings suggest that histamine induction of CNS-mediated hyperglycemia involves neuronal transmission not only via H1 receptors but also, at least in part, by muscarinic cholinergic neurons.
Nonogaki
K
K
Third Department of Internal Medicine, Nagoya University School of Medicine, Japan.
Li
X
X
Tamagawa
T
T
Watanabe
G
G
Hiyoshi
Y
Y
Ozawa
K
K
Sakamoto
N
N
Iguchi
A
A
D000818:Animals; D001285:Atropine / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects*; D002490:Central Nervous System / Q000503:physiopathology; D004305:Dose-Response Relationship, Drug; D006632:Histamine / Q000008:administration & dosage / Q000494:pharmacology*; D006633:Histamine Antagonists / Q000494:pharmacology*; D006943:Hyperglycemia / Q000139:chemically induced* / Q000503:physiopathology; D007276:Injections, Intraventricular; D008297:Male; D018377:Neurotransmitter Agents / Q000502:physiology; D011738:Pyrilamine / Q000008:administration & dosage / Q000494:pharmacology; D011899:Ranitidine / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011976:Receptors, Muscarinic / Q000502:physiology
D006633:Histamine Antagonists; D018377:Neurotransmitter Agents; D011976:Receptors, Muscarinic; D001285:Atropine; D006632:Histamine; D011899:Ranitidine; D011738:Pyrilamine