TY - JOUR
T1 - Serotonin-2B/2C receptors mediate bovine ciliary muscle contraction
T2 - Role in intraocular pressure regulation
AU - Ohia, Sunny E.
AU - Njie-Mbye, Ya Fatou
AU - Robinson, Jenaye
AU - Mitchell, Leah
AU - McKoy, Marshalyn
AU - Opere, Catherine A.
AU - Sharif, Naj A.
PY - 2018/1/1
Y1 - 2018/1/1
N2 - Purpose: To study the pharmacological profile of the serotonin (5-hydroxytryptamine [5-HT]) receptor subtype mediating contractions in bovine isolated ciliary muscles. Methods: Ciliary muscle strips were isolated from bovine eyeballs and mounted in organ baths containing aerated (95% O2, 5% CO2) Krebs buffer solution maintained at 37°C. Each muscle strip was attached at 1 end to a Grass Force-displacement Transducer connected to a Polyview Computer System for recording changes in isometric tension. After an equilibration period, ciliary muscle strips were exposed to selective agonists and antagonists of 5-HT receptors. Results: Both selective and nonselective agonists for 5-HT produced concentration-dependent contractions of isolated ciliary muscles with the following rank order of potency: BW723C86>α-methyl-5-HT>MK-212>>8-hydroxy-DPAT>quipazine>R-DOI>>5-HT>>tryptamine. The selective 5-HT2 receptor antagonists, M-100907 (5-HT2A), RS-127445 (5-HT2B), and RS-102221 (5-HT2C), produced noncompetitive inhibition of the contractile effects of selective agonists yielding antagonist potency (pKB) values of 251 ± 27.2 nM (n = 4), 52.5 ± 6.3 nM (n = 4), and 79.4 ± 9.5 nM (n = 4), respectively. Conclusion: On the basis of the profile of activity of selective agonists and antagonists, we conclude that the 5-HT2B and 5-HT2C receptor subtypes appear to be the predominant serotonin receptors that mediate the contractile action of this amine in bovine isolated ciliary muscles.
AB - Purpose: To study the pharmacological profile of the serotonin (5-hydroxytryptamine [5-HT]) receptor subtype mediating contractions in bovine isolated ciliary muscles. Methods: Ciliary muscle strips were isolated from bovine eyeballs and mounted in organ baths containing aerated (95% O2, 5% CO2) Krebs buffer solution maintained at 37°C. Each muscle strip was attached at 1 end to a Grass Force-displacement Transducer connected to a Polyview Computer System for recording changes in isometric tension. After an equilibration period, ciliary muscle strips were exposed to selective agonists and antagonists of 5-HT receptors. Results: Both selective and nonselective agonists for 5-HT produced concentration-dependent contractions of isolated ciliary muscles with the following rank order of potency: BW723C86>α-methyl-5-HT>MK-212>>8-hydroxy-DPAT>quipazine>R-DOI>>5-HT>>tryptamine. The selective 5-HT2 receptor antagonists, M-100907 (5-HT2A), RS-127445 (5-HT2B), and RS-102221 (5-HT2C), produced noncompetitive inhibition of the contractile effects of selective agonists yielding antagonist potency (pKB) values of 251 ± 27.2 nM (n = 4), 52.5 ± 6.3 nM (n = 4), and 79.4 ± 9.5 nM (n = 4), respectively. Conclusion: On the basis of the profile of activity of selective agonists and antagonists, we conclude that the 5-HT2B and 5-HT2C receptor subtypes appear to be the predominant serotonin receptors that mediate the contractile action of this amine in bovine isolated ciliary muscles.
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U2 - 10.1089/jop.2017.0123
DO - 10.1089/jop.2017.0123
M3 - Article
C2 - 29364761
AN - SCOPUS:85042182998
VL - 34
SP - 70
EP - 75
JO - Journal of Ocular Pharmacology and Therapeutics
JF - Journal of Ocular Pharmacology and Therapeutics
SN - 1080-7683
IS - 1-2
ER -