Gluck Equine Research Center, Dept. of Veterinary Science, University of Kentucky, Lexington, KY, 40546, USA.
Gluck Equine Research Center, Dept. of Veterinary Science, University of Kentucky, Lexington, KY, 40546, USA.
Anim Reprod Sci. 2021 Feb;225:106670. doi: 10.1016/j.anireprosci.2020.106670. Epub 2020 Dec 3.
Reproductive steroids testosterone (T) and estrone sulfate (E1S) are used as diagnostic markers for cryptorchidism in horses. The human chorionic gonadotropin (hCG) stimulation test is used as a diagnostic aid because administration of this hormone results in greater incremental differences in circulating steroid concentrations. Thoughts regarding optimal sampling times following hCG administration, however, are inconsistent. Additionally, determination of half-life of these steroids is important in postsurgical samples to confirm complete removal of testicular tissue. Objectives of this study, therefore, were to determine optimal sampling periods for peak T and E1S after hCG administration and half-life of these steroids after castration. Eight pony stallions were randomly assigned to control or treatment groups (5000 IU hCG). Blood samples were collected following hCG administration. Subsequently, stallions were castrated and blood samples were collected post-castration. The T concentrations were greatest at 72 h after hCG and were greater (P < 0.02) in samples from hCG-treated than control animals: 9,903.4 ± 384 and 784.0 ± 192 pg/mL, respectively (Mean ± SEM). The T concentrations were also greater at 1, 12, 24, 48 and 96 h. The E1S concentrations did not change after administration of hCG. The T response to hCG administration was biphasic with a maximal response between 48-96 h after administration. Half-lives of T and E1S were 1.1 and 0.7 h, respectively, and concentration of T and E1S was similar to that of geldings at 24 h post-castration, which, therefore, should be considered an optimal time to ensure complete castration has occurred.
生殖类固醇睾酮（T）和雌酮硫酸盐（E1S）被用作马隐睾症的诊断标志物。人绒毛膜促性腺激素（hCG）刺激试验被用作诊断辅助手段，因为这种激素的给药会导致循环类固醇浓度的增量差异更大。然而，关于 hCG 给药后最佳采样时间的想法并不一致。此外，确定这些类固醇的半衰期对于手术后样本很重要，以确认睾丸组织已完全切除。因此，这项研究的目的是确定 hCG 给药后 T 和 E1S 的最佳峰值采样时间，以及这些类固醇在去势后的半衰期。8 匹小马驹被随机分配到对照组或治疗组（5000IU hCG）。hCG 给药后采集血液样本。随后，对马驹进行去势，并在去势后采集血液样本。T 浓度在 hCG 给药后 72 小时达到最高，且 hCG 处理组的样本中 T 浓度大于对照组（P<0.02）：分别为 9903.4±384 和 784.0±192 pg/mL（平均值±SEM）。T 浓度在 1、12、24、48 和 96 小时也更高。hCG 给药后 E1S 浓度没有变化。T 对 hCG 给药的反应呈双相性，给药后 48-96 小时达到最大反应。T 和 E1S 的半衰期分别为 1.1 和 0.7 小时，并且在去势后 24 小时 T 和 E1S 的浓度与去势马相似，因此，这应该被认为是确保完全去势发生的最佳时间。
