电场刺激后释放的内源性去甲肾上腺素可引起大鼠输精管的双相收缩。初始的短暂收缩可被30μmol/L兰尼定和2μmol/L硝苯啶减弱,而后继的收缩部分可被2μmol/L硝苯啶消除,但被30μmol/L兰尼定增强。 外加的去甲肾上腺素也可产生输精管的双相收缩,这两相都能被2 μmol/L硝苯啶抑制,兰尼定30μmol/L可使两个相的收缩都减弱50％。我们推测兰尼定的结合位点在输精管的内质网。兰尼定对α-肾上腺素能刺激的不同相的作用不一致,表明对α-肾上腺素能的刺激一收缩偶合有两种方式。 Endogenous norepinephrine released after electric field stimulation can induce biphasic contraction of rat vas deferens. Initial transient contractions were attenuated by 30 μmol / L ranitidine and 2 μmol / L nifedipine, whereas subsequent contractions were eliminated by 2 μmol / L nifedipine but enhanced by 30 μmol / L ranitidine. Addition of norepinephrine also produces vasoconstrictive biphasic contraction, both of which can be inhibited by 2 μmol / L nifedipine, and that lanosidine 30 μmol / L attenuates both phases by 50%. We speculate that laninidine binds to the vas deferens endoplasmic reticulum. Laniiding is not consistent with the effects of the alpha-adrenergic stimuli on different phases, suggesting that there are two ways to stimulate alpha-adrenergic stimulatory-contractile coupling.