Dopamine receptors in the proximal tubule of the rabbit.
Dopamine receptors in the proximal tubule of the rabbit.
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兔子近曲小管中的多巴胺受体。
DOI：
10.1152/ajprenal.1984.247.3.f499
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
Jose,PA
中科院分区：
文献类型：
--
作者：
Felder,RA;Blecher,M;Calcagno,PL;Jose,PA
我们实验室的特点是多巴胺受体在肾小球和肾小管匀浆。由于肾匀浆的异质性限制了这些研究的解释，因此在兔肾的离体近曲小管和直肠部中研究了[3 H]氟哌啶醇结合位点和腺苷酸环化酶对多巴胺的敏感性。[3 H]氟哌啶醇结合位点是可饱和的、立体选择性的和高亲和力的。表观解离常数为31.5 × 10（-9）M（+/-8.5），最大受体密度为0.31 × 10（-15）M（+/-0.08）/mm。在直肠部特异性结合为总[3 H]-氟哌啶醇结合的53%。多巴胺以剂量相关的方式刺激腺苷酸环化酶活性，顺式氟哌噻吨可抑制腺苷酸环化酶活性，反式氟哌噻吨或（-）-普萘洛尔则不能抑制腺苷酸环化酶活性。此外，多巴胺1（D1）激动剂SKF 82526对腺苷酸环化酶活性的刺激作用被D1拮抗剂SCH 23390阻断。近曲小管中的多巴胺受体似乎是D1亚型，因为它们与腺苷酸环化酶的刺激有关。这一点通过（+）-舒必利（一种D1拮抗剂）的立体选择性得到进一步证实，其对[3 H]氟哌啶醇结合位点的亲和力大于（-）-舒必利（一种D2拮抗剂）。
Our laboratory has characterized dopamine receptors in glomeruli and tubular homogenates. Since the heterogeneity of kidney homogenates limits the interpretation of these studies, the [3H]haloperidol binding site and adenylate cyclase sensitivity to dopamine were studied in the isolated proximal convoluted tubule and pars recta of the rabbit kidney. [3H]Haloperidol binding sites were saturable, stereoselective, and of high affinity. The apparent dissociation constant was 31.5 X 10(-9) M (+/- 8.5) and the maximum receptor density was 0.31 X 10(-15) M (+/- 0.08) per millimeter. In pars recta specific binding was 53% of total [3H]-haloperidol binding. Dopamine stimulated adenylate cyclase activity in a dose-related manner, which was inhibited by cis-flupenthixol but not by trans-flupenthixol or (-)-propranolol. Moreover, the stimulatory effect of the dopamine 1 (D1) agonist SKF 82526 on adenylate cyclase activity was blocked by the D1 antagonist SCH 23390. Dopamine receptors in the proximal convoluted tubule appear to be of the D1 subtype since they are linked to stimulation of adenylate cyclase. This is further substantiated by the stereoselectivity for (+)-sulpiride (a D1 antagonist), which had a greater affinity for the [3H]haloperidol binding site than (-)-sulpiride (a D2 antagonist).