Premium
Brain Histaminergic System in Mast Cell‐Deficient ( Ws/Ws ) Rats: Histamine Content, Histidine Decarboxylase Activity, and Effects of ( S )α‐Fluoromethylhistidine
Author(s) -
Sugimoto Koreaki,
Maeyama Kazutaka,
Alam Md. Khorshed,
Sakurai Eiko,
Onoue Hitoshi,
Kasugai Tsutomu,
Kitamura Yukihiko,
Watanabe Takehiko
Publication year - 1995
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.1995.65020791.x
Subject(s) - histaminergic , histamine , histidine decarboxylase , endocrinology , medicine , cerebellum , chemistry , histamine n methyltransferase , cerebral cortex , histamine h3 receptor , mast cell , pia mater , biology , histidine , histamine h2 receptor , biochemistry , anatomy , immunology , receptor , agonist , antagonist , enzyme
The mast cell‐deficient [ Ws/Ws ( W hite spotting in the skin)] rat was investigated with regard to the origin of histamine in the brain. No mast cells were detected in the pia mater and the perivascular region of the thalamus of Ws/Ws rats by Alcian Blue staining. The histamine contents and histidine decarboxylase (HDC) activities of various brain regions of Ws/Ws rats were similar to those of +/+ rats except the histamine contents of the cerebral cortex and cerebellum. As the cerebral cortex and cerebellum have meninges that are difficult to remove completely, the histamine contents of these two regions may be different between Ws/Ws and +/+ rats. We assume that the histamine content of whole brain with meninges in Ws/Ws rats is <60% of that in +/+ rats. So we conclude that approximately half of the histamine content of rat brain is derived from mast cells. Next, the effects of ( S )α‐fluoromethylhistidine (FMH), a specific inhibitor of HDC, on the histamine contents and HDC activities of various regions of the brain were examined in Ws/Ws rats. In the whole brain of Ws/Ws rats, 51 and 37% of the histamine content of the control group remained 2 and 6 h, respectively, after FMH administration (100 mg/kg of body weight). Therefore, we suggest that there might be other histamine pools including histaminergic neurons in rat brain.