Korean J Urol.  2004 Jul;45(7):726-731.

Contraction and Relaxation Responses of Isolated Rabbit Seminal Vesicle to Selective beta Subtypes-adrenoceptor Agonists and Antagonists

• Myung SC
• Keum EM
• Kwak KW
• Lee MY
• Kim SC

Abstract

PURPOSE: This study was aimed at investigating the role of betaadrenoceptor subtypes in mediating the relaxation and contraction of seminal vesicles in rabbits.
MATERIALS AND METHODS
Relaxation or contractile responses of epithelium- removed muscle strips of a rabbit seminal vesicle, which were precontracted with 10-5M norepinephrine, to selective betasubtypes-adrenoceptor agonists were observed in an organ bath. The contractile responses induced by isoproterenol were also observed after application of selective antagonists.
RESULTS
Isoproterenol showed a concentration-dependent contractile response, but the contractility was weaker than those with phenylephrine and norepinephrine. The betaselective-agonists(xamoterol for beta, clenbuterol for beta and BRL37344 for beta) alone evoked neither contraction nor relaxation. However, the beta- and beta-agonists inhibited the contraction of the precontracted strips with 10-5M norepinephrine, while the beta-agonist enhanced the contraction. The pretreatment with a beta-antagonist(ICI118551) reduced the tension of the strips developed by 10-4M isoproterenol, but the beta-(atenolol) and beta-(SR59230A) antagonists showed no changes in the response.
CONCLUSIONS
beta- and beta-adrenoceptors seem to mediate the relaxation of the seminal vesicle, while the beta-adrenoceptor may have a supplementary role in contraction.

Keyword

Seminal vesicle; Beta-adrenoceptor; Contraction; Relaxation

MeSH Terms

Baths
Clenbuterol
Isoproterenol
Negotiating
Norepinephrine
Phenylephrine
Rabbits
Relaxation*
Seminal Vesicles*
Clenbuterol
Isoproterenol
Norepinephrine
Phenylephrine