Z. Chen
Apr 1, 2001
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Influential Citations
8
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Journal
Acta pharmacologica Sinica
Abstract
AIM The effect of clobenpropit on regional cerebral blood flow (rCBF) was investigated in the rat hippocampus. METHODS rCBF was determined in the hippocampus by the hydrogen clearance method. The blood pressure was measured by a tail-cuff plethysmograph. RESULTS Intracerebroventricular (icv) injection of clobenpropit (20, 50 microg), a representative H3-antagonist, dose-dependently and significantly increased rCBF in the hippocampus. The increase of rCBF induced by clobenpropit was enhanced by metoprine (1, 2 mg/kg), a selective histamine N-methyltransferase inhibitor; however, was antagonized by an H3-agonist, (R)-alpha-methylhistamine (5 microg), an H(1)-antagonist, mepyramine (5-10 mg/kg), and an H2-antagonist, zolantidine (10 mg/kg). Clobenpropit caused no apparent effects on blood pressure even at a high dose of 50 microg. CONCLUSION These results suggest that brain endogenous histamine may contribute to increase rCBF in the rat hippocampus via both the post-synaptic H1-, H2-receptors and the pre-synaptic H3-receptor.