Zoller D, Lüttgenau J, Steffen S, Bollwein H
Vetsuisse Faculty, Clinic of Reproductive Medicine, University of Zurich, Zurich, Switzerland.
Vetsuisse Faculty, Clinic of Reproductive Medicine, University of Zurich, Zurich, Switzerland.
Theriogenology. 2016 Jun;85(9):1562-1567. doi: 10.1016/j.theriogenology.2016.01.009. Epub 2016 Jan 14.
Poor uterine perfusion has been proposed as a cause of infertility in mares. The objective of this study was to investigate the effect of isosorbide dinitrate (ISDN), a nitric oxide donor, on uterine and ovarian blood flow resistance during diestrus and early pregnancy in mares. Six Trotter mares, aged 7 to 14 years, were examined daily during the first 11 days of three diestrous periods, and five of those mares were also examined during the first 11 days of two pregnancies. Six mares randomly received a placebo, a low dose (30 mg, ISDN30), or a high dose of ISDN (60 mg, ISDN60) through three nonconsecutive cycles. The treatments were administered orally, every 12 hours from Day 1 to 11 of the cycle (Day 0 = ovulation). Five of the 6 mares received a placebo or 60 mg of ISDN orally every 12 hours from Day 1 to 11 of pregnancy. The mares were short cycled on Day 12 of each trial. Transrectal color Doppler was used to determine blood flow resistance semiquantitatively and expressed as pulsatility index. Mean pulsatility index of both uterine arteries combined and of the dominant (ipsilateral to the CL) ovarian artery was lower (treatment effects: P ≤ 0.01; time effects: P ≤ 0.002) in mares receiving 30 mg or 60 mg of ISDN compared with placebo-treated mares. Blood flow resistance in the dominant ovarian artery was lower in ISDN-treated pregnant mares than in placebo-treated pregnant and cycling mares (treatment effect: P = 0.04; time effect: P = 0.003). Isosorbide dinitrate increases uterine and ovarian perfusion in cycling mares and ovarian perfusion in early pregnant mares. Further studies are needed to investigate these effects in relation to fertility of the mare.
子宫灌注不良被认为是母马不育的一个原因。本研究的目的是调查一氧化氮供体硝酸异山梨酯（ISDN）对母马发情间期和妊娠早期子宫及卵巢血流阻力的影响。六匹7至14岁的 Trotter 母马在三个发情间期的前11天每天接受检查，其中五匹母马在两次妊娠的前11天也接受检查。六匹母马通过三个不连续的周期随机接受安慰剂、低剂量（30毫克，ISDN30）或高剂量的ISDN（60毫克，ISDN60）。治疗从周期的第1天至11天每12小时口服一次（第0天 = 排卵）。6匹母马中有5匹在妊娠的第1天至11天每12小时口服一次安慰剂或60毫克ISDN。在每个试验的第12天对母马进行短期发情周期处理。经直肠彩色多普勒用于半定量确定血流阻力，并表示为搏动指数。与接受安慰剂治疗的母马相比，接受30毫克或60毫克ISDN的母马双侧子宫动脉和优势（与黄体同侧）卵巢动脉的平均搏动指数较低（治疗效果：P≤0.01；时间效果：P≤0.002）。接受ISDN治疗的妊娠母马优势卵巢动脉的血流阻力低于接受安慰剂治疗的妊娠母马和发情周期母马（治疗效果：P = 0.04；时间效果：P = 0.003）。硝酸异山梨酯可增加发情周期母马的子宫和卵巢灌注以及妊娠早期母马的卵巢灌注。需要进一步研究以调查这些影响与母马生育力的关系。
