牛阴茎退缩肌和阴茎动脉中内皮素受体的功能特性

Functional characterization of endothelin receptors in the bovine retractor penis muscle and penile artery.

作者信息

Parkkisenniemi U M, Klinge E

机构信息

Department of Pharmacy, University of Helsinki, Finland.

出版信息

Pharmacol Toxicol. 1996 Aug;79(2):73-9. doi: 10.1111/j.1600-0773.1996.tb00245.x.

DOI:10.1111/j.1600-0773.1996.tb00245.x

PMID:8878249

Abstract

The effects of endothelin-1 and sarafotoxin 6c on the bovine retractor penis muscle and the bovine penile artery were studied, and a functional characterization of endothelin receptors in these tissues was performed by using the ETA-receptor antagonist BQ-123 and the ETB-receptor antagonist IRL 1038. The retractor penis muscle and the penile artery were about equipotently contracted by endothelin-1 in a concentration-dependent manner the EC50 values being 3.5 x 10(-9) M and 1.3 x 10(-9) M, respectively. In both tissues BQ-123 (10(-6) M) inhibited maximal contraction induced by endothelin-1 by about 50%. Sarafotoxin 6c substantially relaxed the retractor penis muscle, and to a lesser extent also the penile artery, whereas endothelin-1 did not relax either tissue. The sarafotoxin 6c-induced relaxation of the retractor penis muscle was totally inhibited by IRL 1038 (3 x 10(-6) M) and the nitric oxide synthase inhibitor L-NNA (10(-4) M). In both tissues L-NNA enhanced the contraction induced by endothelin-1 and lowered the threshold concentration for it. The results show that in both tissues the contraction induced by endothelin-1 was mediated primarily by ETA-receptors. The retractor penis muscle is also equipped with ETB-receptors, probably at least in part located on the inhibitory nerves, which mediate relaxation via activation of the L-arginine nitric oxide synthase pathway.

摘要

研究了内皮素 -1 和色拉毒素 6c 对牛阴茎退缩肌和牛阴茎动脉的影响，并使用 ETA 受体拮抗剂 BQ -123 和 ETB 受体拮抗剂 IRL 1038 对这些组织中的内皮素受体进行了功能表征。内皮素 -1 以浓度依赖性方式使阴茎退缩肌和阴茎动脉产生近似等效的收缩，EC50 值分别为 3.5×10⁻⁹ M 和 1.3×10⁻⁹ M。在这两种组织中，BQ -123（10⁻⁶ M）可抑制内皮素 -1 诱导的最大收缩约 50%。色拉毒素 6c 可使阴茎退缩肌显著舒张，对阴茎动脉的舒张作用较小，而内皮素 -1 对两种组织均无舒张作用。色拉毒素 6c 诱导的阴茎退缩肌舒张完全被 IRL 1038（3×10⁻⁶ M）和一氧化氮合酶抑制剂 L -NNA（10⁻⁴ M）抑制。在这两种组织中，L -NNA 增强了内皮素 -1 诱导的收缩并降低了其阈浓度。结果表明，在这两种组织中，内皮素 -1 诱导的收缩主要由 ETA 受体介导。阴茎退缩肌还配备有 ETB 受体，可能至少部分位于抑制性神经上，其通过激活 L -精氨酸一氧化氮合酶途径介导舒张。