To facilitate transcervical artificial insemination in sheep, the effects of local treatment with α1-adrenergic receptor antagonists on cervix dilation and hemodynamics were evaluated. Ewes (n = 7) were subjected to oestrous synchronisation every 40 days and assigned to treatments in a Latin square experimental design (seven animals × seven periods) with a factorial treatment arrangement (A × B), Factors A (prazosin or tamsulosin) and B (1, 2, or 4 mg/animal). Ewes of the six treatment groups (P1, P2, P4, T1, T2, and T4) were administered α1-adrenergic receptor antagonists while those of the control group (CG) were administered only α1-adrenergic antagonist carrier agent. Distance that the transcervical catheter penetrated without cervical resistance, mean arterial pressure, and uterine artery dopplerfluxometry were evaluated before and after 30 min, 1, 2, 4, 8, and 10 h of treatment. Catheter penetration distance was greater in ewes of the T4 and P4 groups (P < 0.01), with there being a positive correlation between dose and distance (r = 0.243). The penetration distance was similar (P = 0.84) for treated groups, with the greatest penetration occurring 2, 4, and 6 h after treatment (P < 0.01). The passage into the uterine lumen was greater (P = 0.013) in ewes of the P4 (17.9 %) and T4 (19.6 %) groups. There were no effects on blood pressure or uterine blood flow (P> 0.05). These preliminary results indicate there are benefits of treatment with 4 mg/animal of tamsulosin or prazosin in catheter passage through the sheep cervix 2–6 h after administration without hemodynamic effects.

为了促进绵羊经宫颈人工授精，评估了用 α1-肾上腺素能受体拮抗剂局部治疗对宫颈扩张和血流动力学的影响。母羊 ( n= 7) 每 40 天进行一次发情同步，并分配到拉丁方实验设计（7 只动物 × 7 个时期）中的治疗，因子治疗安排 (A × B)、因子 A（哌唑嗪或坦索罗辛）和 B（1 、2 或 4 毫克/动物）。六个治疗组（P1、P2、P4、T1、T2和T4）的母羊给药α1-肾上腺素能受体拮抗剂，而对照组（CG）的母羊仅给药α1-肾上腺素能受体拮抗剂。在治疗 30 分钟、1、2、4、8 和 10 小时之前和之后评估经宫颈导管在没有宫颈阻力的情况下穿透的距离、平均动脉压和子宫动脉多普勒血流测定法。T4和P4组母羊的导管穿透距离更大（P< 0.01），剂量和距离之间呈正相关（r = 0.243）。治疗组的穿透距离相似（P = 0.84），最大穿透发生在治疗后 2、4 和 6 小时（P < 0.01）。P4 (17.9 %) 和 T4 (19.6 %) 组的母羊进入子宫腔的次数更多 ( P = 0.013)。对血压或子宫血流量无影响（P > 0.05）。这些初步结果表明，在给药后 2-6 小时通过导管通过绵羊子宫颈时，用 4 毫克/动物坦索罗辛或哌唑嗪进行治疗是有益的，而不会对血液动力学产生影响。