Abstract
The pharmacological properties of SGB-1534, 3-[2-[4-[(o-methoxyphenyl)-1-piperazinyl]ethyl]-2,4(1H,3H)- quinazolinedione monohydrochloride, a selective alpha 1-adrenoceptor antagonist, compared with prazosin, phentolamine and yohimbine, were examined in contractile responses of isolated canine mesenteric arteries and veins and femoral arteries and veins to exogenous noradrenaline. The arteries and veins concentration-dependently contracted when exposed to noradrenaline. The sensitivity to noradrenaline, when compared in terms of pD2 values, was significantly higher in the veins than in the arteries. Phentolamine and yohimbine were competitive antagonists against noradrenaline in the arteries and the veins. SGB-1534 and prazosin caused a parallel shift to the right of the concentration-response curves for noradrenaline only in the arteries: the two antagonists were less effective in the veins than in the arteries when low concentrations of noradrenaline were applied. The pharmacological characteristics of SGB-1534 resemble those of prazosin. The pA2 values for SGB-1534 against noradrenaline in the arteries were much higher than those for prazosin, phentolamine and yohimbine. The result indicates that SGB-1534 may predominantly act upon arterial resistance vessels rather than the venous side, resulting in potent hypotension.
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
