The results may indicate that the alpha(1)-adrenoceptor-induced contraction was mediated by Ca(2+) influx through T- and L-type Ca(2+) channels for the early and late alpha(1)-components, respectively and that SK and BK channels contributed to protect the musculature of the guinea-pig vas deferens from excess tension development induced by sympathetic volley. Neurourol. Urodynam. 28:447-454, 2009. (c) 2009 Wiley-Liss, Inc.