ETB2 receptor subtype stimulation relaxes the iris sphincter muscle

Title:

ETB2 receptor subtype stimulation relaxes the iris sphincter muscle

Creator:

Rocha-Sousa, A., Saraiva, J., Amaral, M., Alves-Faria, P., Falcão-Reis, F., and Leite-Moreira, A. F.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:dda03fa3-0d00-4ace-b3de-796bf034ecaa
uuid:dda03fa3-0d00-4ace-b3de-796bf034ecaa

Subject:

Fyziologie člověka a srovnávací fyziologie, fyziologie, duhovka, physiology, iris (eye), peptidové hormony, svalová vlákna, ETB2, peptide hormones, muscle fibers, ETB2 (endothelin), sarafotoxin-s6c, 14, and 612

Type:

article, články, model:article, and TEXT

Description:

Effects of ETB receptor stimulation and its subcellular pathways were evaluated in carbachol pre-contracted rabbit iris sphincter muscles (n=51). ETB stimulation with sarafotoxin (SRTX-c; 10-10-10-6 M) was tested in the absence (n=7) or presence of 10-5 M of: BQ-788 (ETB2 receptor antagonist; n=6), L-NA (NOS inhibitor; n=7) or indomethacin (cyclooxygenase inhibitor; n=10). Effects of ETB stimulation by endothelin-1 (ET-1; 10-10–10-7 M) in the presence of an ETA receptor antagonist (BQ-123; 10-5 M; n=7) and of ETB1 stimulation by IRL-1620 (10-10–10-7 M; n=7) were also tested. Finally, the effects of SRTX-c (10 -9 –10 -7 M) in electric field stimulation (EFS) contraction were evaluated (n=7). ETB receptor stimulation by SRTX-c or ET-1 in presence of BQ-123 promoted a concentration-dependent relaxation of the rabbit iris sphincter muscle by 10.8±2.0 % and 9.4±1.8 %, respectively. This effect was blocked by BQ-788 (-2.3±2.0 %), L-NA (4.5±2.3 %) or indomethacin (2.3±2.9 %). Selective ETB1 stimulation by IRL-1620 did not relax the iris sphincter muscle (0.9±5.4 %). EFS elicited contraction was not altered by SRTX-c. In conclusion, ETB receptor stimulation relaxes the carbachol precontracted iris sphincter muscle, an effect that is mediated by the ETB2 receptor subtype, through NO and the release of prostaglandins., A. Rocha-Sousa ... [et al.]., and Obsahuje seznam literatury

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Physiological research | 2009 Volume:58 | Number:6

Harvested from:

CDK

Metadata only:

false