Effects of indoramin in rat vas deferens and aorta: concomitant alpha(1)-adrenoceptor and neuronal uptake blockade


Autoria(s): Pupo, A. S.; Cavenaghi, DLC; Campos, M.; Morais, P. D.; Jurkiewicz, N. H.; Jurkiewicz, A.
Contribuinte(s)

Universidade Estadual Paulista (UNESP)

Data(s)

20/05/2014

20/05/2014

01/08/1999

Resumo

1 the actions of the alpha(1)-adrenoceptor antagonist indoramin have been examined against the contractions induced by noradrenaline in the rat vas deferens and aorta taking into account a putative neuronal uptake blocking activity of this antagonist which could. result in self-cancelling actions.2 Indoramin behaved as a simple competitive antagonist of the contractions induced by noradrenaline in the vas deferens and aorta yielding pA(2) values of 7.38 +/- 0.05 (slope = 0.98 +/- 0.03) and 6.78 +/- 0.14 (slope = 1.08 +/- 0.06), respectively.3 When the experiments were repeated in the presence of cocaine (6 mu M) the potency (pA(2)) of indoramin in antagonizing the contractions of the vas deferens to noradrenaline was increased to 8.72 +/- 0.07 (slope = 1.10 +/- 0.05) while its potency remained unchanged in the aorta (pA(2) = 6.69 +/- 0.12; slope = 1.04 +/- 0.05).4 In denervated vas deferens, indoramin antagonized the contractions to noradrenaline with a potency similar to that found in the presence of cocaine (8.79 +/- 0.07; slope = 1.09 +/- 0.06).5 It is suggested that indoramin blocks alpha(1)-adrenoceptors and neuronal uptake in rat vas deferens resulting in Schild plots with slopes not different from unity even in the absence of selective inhibition of neuronal uptake. As a major consequence of this double mechanism of action, the pA(2) values for this antagonist are underestimated when calculated in situations where the neuronal uptake is active, yielding spurious pK(B) values.

Formato

1832-1836

Identificador

http://dx.doi.org/10.1038/sj.bjp.0702735

British Journal of Pharmacology. Basingstoke: Stockton Press, v. 127, n. 8, p. 1832-1836, 1999.

0007-1188

http://hdl.handle.net/11449/17473

10.1038/sj.bjp.0702735

WOS:000082312500010

WOS000082312500010.pdf

Idioma(s)

eng

Publicador

Stockton Press

Relação

British Journal of Pharmacology

Direitos

openAccess

Palavras-Chave #indoramin #alpha(1)-adrenoceptors #vas deferens #aorta
Tipo

info:eu-repo/semantics/article