The Characteristics of Endothelin Receptor Subtypes on Muscle Contraction and Neuro-transmission in Rat Vas Deferens
| Autor: | Noriko Ohshima, Issei Takayanagi, Mitsutoshi Satoh, Mikiko Takada, Katsuo Koike |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Endothelin Receptor Antagonists
Male medicine.medical_specialty Contraction (grammar) medicine.drug_class Pharmaceutical Science Stimulation Viper Venoms In Vitro Techniques Biology Neurotransmission Synaptic Transmission Vas Deferens Internal medicine medicine Animals Vasoconstrictor Agents Rats Wistar Receptor Pharmacology Receptors Endothelin Endothelins Prostate Vas deferens General Medicine Receptor antagonist Electric Stimulation Peptide Fragments Rats medicine.anatomical_structure Endocrinology medicine.symptom Endothelin receptor Muscle Contraction Muscle contraction |
| Zdroj: | Biological and Pharmaceutical Bulletin. 21:718-722 |
| ISSN: | 1347-5215 0918-6158 |
| Popis: | We observed endothelin (ET)-induced contractile responses on prostatic and epididymal segments, as well as the facilitation of an electrically stimulated tone on prostatic segments of isolated rat vas deferens. In both segments, the selective ET(B)-receptor agonists, IRL 1620 and sarafotoxin S6c, produced only a small contraction or no contraction at a concentration of 1 microM. The rank order of contraction potencies (pD2 value) was ET-1 = ET-2 > ET-3 >> sarafotoxin S6c = IRL 1620. The maximum responses of ET-induced contractions in the prostatic segments were larger than those in the epididymal segments. The contractile response to ET-3 was antagonized by pretreatment for 30 min with BQ-123 (10 nM), a selective ET(A) receptor antagonist, and BQ-788 (1 microM), a selective ET(B) receptor antagonist. The contractile responses to ET-1 were antagonized by pretreatment with BQ-123 (10 microM), but not with BQ-788 (1 microM). The ET-3-induced facilitation on the twitch response to electrical stimulation in the prostatic segment of the vas deferens was antagonized by BQ-123 (0.1 microM) and BQ-788 (1 microM). The ET-1-induced facilitation was antagonized by pretreatment with BQ-123 (3 microM), but not with BQ-788 (10 microM). These results suggest that in rat vas deferens the ET(A) receptors are divided into BQ-123-sensitive ET(A1) and BQ-123-insensitive ET(A2) subtypes, and the production of a contractile response of smooth muscle as well as the facilitation of neurotransmission are accomplished through mediation by ET(A1)- and ET(A2)-subtypes. |
| Databáze: | OpenAIRE |
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