Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran.
Department of Animal Biotechnology, Reproductive Biomedicine Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran.
BMC Vet Res. 2022 Mar 15;18(1):98. doi: 10.1186/s12917-022-03194-8.
The present study was conducted to determine if using α-adrenergic agonists results in decreased stress levels (lower cortisol levels) in goats used for laparoscopic embryo [somatic cell nuclear transfer (SCNT)] transfer; and there is an effect on pregnancy rate when stress levels are lessened. Sixty healthy does aged 24 ± 4 months and weighing 30 ± 3 kg were used in experimental, prospective, randomized and blinded study. In this study, embryos were obtained by the Somatic Cell Nuclear Transfer (SCNT) method. Animals were randomly assigned to five groups: control (normal saline); xylazine (100 μg kg); detomidine (50 μg kg); medetomidine (20 μg kg); and dexmedetomidine (5 μg kg). Embryo transfer (through laparoscopic technique) began at 15 min and continued till 45 min post-treatment. Heart rate (HR), respiratory rate (RR), rectal temperature (RT), and ruminal motility were performed before (baseline) and after drug administration. Pregnancy detection was performed 38 days after embryo transfer.
Compared to control, HR, RR and ruminal motility were significantly lower in α-adrenergic agonists groups at 5-90, 15-60, and 5-120 min, respectively. Serum cortisol values significantly increased from baseline in the control group 45 min after drug administration (p = 0.001). At time points 45 and 60 min, serum cortisol concentration was significantly lower in α-adrenergic agonists groups compared with the control. The pregnancy rate in control group (n = 4/12, 33.3%) was significantly lower than xylazine (n = 9/12, 75%; p = 0.041), detomidine (n = 10/12, 83.3%; p = 0.013), medetomidine (n = 9/12, 75%; p = 0.041) and dexmedetomidine (n = 10/12, 83.3%; p = 0.013); but no significant differences were observed among different α-adrenergic agonists groups.
Alph-adrenergic agonists were effective on increasing the pregnancy rate of recipient goats receiving cloned embryos. No significant differences were detected among different α-adrenergic agonists.
本研究旨在确定使用 α-肾上腺素能激动剂是否会降低用于腹腔镜胚胎[体细胞核转移（SCNT）]转移的山羊的应激水平（较低的皮质醇水平）；并且当应激水平降低时，对妊娠率有影响。
实验采用前瞻性、随机和盲法设计，使用 60 只健康的 24±4 月龄、体重 30±3kg 的母羊。在这项研究中，胚胎是通过体细胞核转移（SCNT）方法获得的。动物随机分为五组：对照组（生理盐水）；赛拉嗪（100μg/kg）；地托咪定（50μg/kg）；美托咪定（20μg/kg）；右美托咪定（5μg/kg）。胚胎移植（通过腹腔镜技术）在治疗后 15 分钟开始，持续 45 分钟。在给药前（基线）和给药后测量心率（HR）、呼吸频率（RR）、直肠温度（RT）和瘤胃运动。胚胎移植后 38 天进行妊娠检测。
与对照组相比，α-肾上腺素能激动剂组在 5-90、15-60 和 5-120min 时 HR、RR 和瘤胃运动显著降低。对照组在给药后 45min 时血清皮质醇值从基线显著升高（p=0.001）。在 45 和 60min 时，α-肾上腺素能激动剂组的血清皮质醇浓度明显低于对照组。对照组的妊娠率（n=4/12，33.3%）明显低于赛拉嗪组（n=9/12，75%；p=0.041）、地托咪定组（n=10/12，83.3%；p=0.013）、美托咪定组（n=9/12，75%；p=0.041）和右美托咪定组（n=10/12，83.3%；p=0.013）；但不同的α-肾上腺素能激动剂组之间无显著差异。
α-肾上腺素能激动剂可有效提高接受克隆胚胎的受体山羊的妊娠率。不同的 α-肾上腺素能激动剂之间没有发现显著差异。
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