TY - JOUR
T1 - The effect of dopamine D1 receptor stimulation on the up-regulation of histamine H3-receptors following destruction of the ascending dopaminergic neurones
AU - Ryu, Jong Hoon
AU - Yanai, Kazuhiko
AU - Zhao, Xiao Lan
AU - Watanabe, Takehiko
PY - 1996
Y1 - 1996
N2 - 1. The binding of [3H]-(R)α-methylhistamine and [3H]-N(α)-methylhistamine to histamine H3-receptors, [3H]-SCH23390 to dopamine D1-receptors, and [3H]-YM09151-2 to dopamine D2-receptors was investigated by quantitative receptor autoradiography in the rat brain following 6-hydroxydopamine injection into the substantia nigra. 2. The levels of [3H]-(R)α-methylhistamine binding sites in the denervated striatum and substantia nigra were significantly higher than those in the contralateral side from 1 week to 12 weeks after nigral lesions. The H3-receptor binding was maximal at 3 weeks after nigral lesions and maintained until 12 weeks. 3. The increased number of histamine H3-receptors was decreased to the level of the contralateral side by chronic treatment with a selective dopamine D1 agonist, SKF38393, but not modified by a selective dopamine D2 agonist, quinpirole. 4. Dopamine D1- and D2-receptors in the striatum were similarly up-regulated after unilateral nigral lesion. On the other hand, the number of dopamine D1-receptors in the substantia nigra was markedly decreased after administration of 6-hydroxydopamine. 5. The treatment with (S)α-fluoromethylhistidine increased the H3-receptor binding in both the ipsilateral and contralateral sides. As a result, the magnitude of the ratio of the H3-receptor binding between ipsilateral and contralateral sides was partially attenuated by treatment with (S)-α-fluoromethylhistidine. 6. These results strongly suggest that the expression of histamine H3-receptors in the striatum and substantia nigra is influenced through D1-receptors by tonic nigrostriatal dopaminergic inputs.
AB - 1. The binding of [3H]-(R)α-methylhistamine and [3H]-N(α)-methylhistamine to histamine H3-receptors, [3H]-SCH23390 to dopamine D1-receptors, and [3H]-YM09151-2 to dopamine D2-receptors was investigated by quantitative receptor autoradiography in the rat brain following 6-hydroxydopamine injection into the substantia nigra. 2. The levels of [3H]-(R)α-methylhistamine binding sites in the denervated striatum and substantia nigra were significantly higher than those in the contralateral side from 1 week to 12 weeks after nigral lesions. The H3-receptor binding was maximal at 3 weeks after nigral lesions and maintained until 12 weeks. 3. The increased number of histamine H3-receptors was decreased to the level of the contralateral side by chronic treatment with a selective dopamine D1 agonist, SKF38393, but not modified by a selective dopamine D2 agonist, quinpirole. 4. Dopamine D1- and D2-receptors in the striatum were similarly up-regulated after unilateral nigral lesion. On the other hand, the number of dopamine D1-receptors in the substantia nigra was markedly decreased after administration of 6-hydroxydopamine. 5. The treatment with (S)α-fluoromethylhistidine increased the H3-receptor binding in both the ipsilateral and contralateral sides. As a result, the magnitude of the ratio of the H3-receptor binding between ipsilateral and contralateral sides was partially attenuated by treatment with (S)-α-fluoromethylhistidine. 6. These results strongly suggest that the expression of histamine H3-receptors in the striatum and substantia nigra is influenced through D1-receptors by tonic nigrostriatal dopaminergic inputs.
KW - (S)-α-fluoromethylhistidine
KW - 6-hydroxydopamine
KW - Denervation
KW - Dopamine D-receptors
KW - Dopamine D-receptors
KW - Histamine H-receptor
KW - Quinpirole
KW - SKF38393
KW - Striatum
KW - Substantia nigra
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U2 - 10.1111/j.1476-5381.1996.tb15441.x
DO - 10.1111/j.1476-5381.1996.tb15441.x
M3 - Article
C2 - 8762081
AN - SCOPUS:0029658966
VL - 118
SP - 585
EP - 592
JO - British Journal of Pharmacology
JF - British Journal of Pharmacology
SN - 0007-1188
IS - 3
ER -