Strömberg C, Tsutsumi K, Viswanathan M, Saavedra J M
Section on Pharmacology, National Institute of Mental Health, Bethesda, MD 20892.
Eur J Pharmacol. 1991 Dec 12;208(4):331-6. doi: 10.1016/0922-4106(91)90079-w.
Angiotensin II receptor number was higher in superior cervical ganglia of 2-week-old when compared to 8-week-old rats. In both young and adult rats, specific binding of [125I][Sar1]angiotensin II was displaced competitively by the AT1-receptor antagonist DuP 753 but not by the AT2-receptor competitor PD 123177. In ganglia from adult rats, DuP 753 competed with an IC50 of 113 nM. The stable guanine nucleotide GTP gamma S inhibited binding of [125I][Sar1]angiotensin II in young and adult rats by approximately 50% with IC50 values of 105 and 120 nM, respectively, suggesting that the angiotensin receptor is G-protein linked. Angiotensin II at a dose of 1 microM stimulated inositol phosphate formation 58% over control values in superior cervical ganglia from 8-week-old rats. This effect was totally blocked by 10 microM DuP 753 but not by 10 microM PD 123177. Our findings demonstrate that rat superior cervical ganglia contain AT1-type angiotensin receptors that are probably G-protein linked, and their stimulation results in increased inositol phospholipid metabolism.
与8周龄大鼠相比，2周龄大鼠颈上神经节中的血管紧张素II受体数量更多。在幼年和成年大鼠中，[125I][Sar1]血管紧张素II的特异性结合可被AT1受体拮抗剂DuP 753竞争性取代，但不能被AT2受体竞争者PD 123177取代。在成年大鼠的神经节中，DuP 753以113 nM的IC50进行竞争。稳定的鸟嘌呤核苷酸GTPγS在幼年和成年大鼠中分别以105和120 nM的IC50值抑制[125I][Sar1]血管紧张素II的结合约50%，这表明血管紧张素受体与G蛋白相连。1 microM剂量的血管紧张素II刺激8周龄大鼠颈上神经节中的肌醇磷酸形成，比对照值增加58%。这种效应被10 microM DuP 753完全阻断，但未被10 microM PD 123177阻断。我们的研究结果表明，大鼠颈上神经节含有可能与G蛋白相连的AT1型血管紧张素受体，其刺激会导致肌醇磷脂代谢增加。
