There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
The action of clenbuterol, beta(2)-adrenoceptor agonist, on the contractile response
of isolated rat detrusor muscle strips was investigated in vitro. Clenbuterol (10(-5)
M) inhibited the detrusor muscle frequency response (1-40 Hz, p<0.02) with a more
pronounced effect at 1 Hz than 40 Hz. Clenbuterol (10(-6) M) significantly inhibited
the contractile response to exogenous ATP (10(-4) to 10(-2) M, p<0.05) but not to
carbachol (10(-9) to 10(-4) M). The presence of 10(-5) M ICI 118, 551, beta(2)-adrenoceptor
antagonist, shifted significantly the clenbuterol dose-response to 1 Hz electrical
field stimulation (EC(50) 3.4x10(-6) M (+/-2.2x10(-6) M) for clenbuterol alone, to
4.1x10(-4) M (+/-8.8 x10(-5) M), P<0.05). In conclusion, clenbuterol inhibits electrical
field and ATP-stimulated contractions of detrusor muscle. Reversal of the clenbuterol
inhibition of detrusor muscle contraction by ICI 118, 551 shows that clenbuterol is
probably acting through postsynaptic beta(2)-adrenoceptors, which modulate the response
to ATP released from purinergic nerves.