Sugimoto K, Maeyama K, Alam K, Sakurai E, Onoue H, Kasugai T, Kitamura Y, Watanabe T
Department of Pharmacology I, Tohoku University School of Medicine, Sendai, Japan.
J Neurochem. 1995 Aug;65(2):791-7. doi: 10.1046/j.1471-4159.1995.65020791.x.
The mast cell-deficient [Ws/Ws (White 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) alpha-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.
对肥大细胞缺陷型[Ws/Ws（皮肤白斑）]大鼠脑内组胺的来源进行了研究。通过阿尔辛蓝染色，在Ws/Ws大鼠的软脑膜和丘脑的血管周围区域未检测到肥大细胞。除大脑皮层和小脑的组胺含量外，Ws/Ws大鼠各脑区的组胺含量和组氨酸脱羧酶（HDC）活性与+/+大鼠相似。由于大脑皮层和小脑有难以完全去除的脑膜，Ws/Ws和+/+大鼠这两个区域的组胺含量可能有所不同。我们推测Ws/Ws大鼠带脑膜的全脑组胺含量<+/+大鼠的60%。因此我们得出结论，大鼠脑内约一半的组胺含量来自肥大细胞。接下来，在Ws/Ws大鼠中研究了HDC特异性抑制剂（S）α-氟甲基组氨酸（FMH）对脑内各区域组胺含量和HDC活性的影响。在Ws/Ws大鼠的全脑中，给予FMH（100mg/kg体重）后2小时和6小时，对照组组胺含量分别剩余51%和37%。因此，我们认为大鼠脑内可能存在包括组胺能神经元在内的其他组胺池。
