Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, CEU-Cardenal Herrera University, Tirant lo Blanc, 7, Alfara del Patriarca, 46115, Valencia, Spain.
Department of Veterinary Sciences, Veterinary Physiology Unit, Polo Universitario Annunziata, Via Palatucci 13, 98168, Messina, Italy.
Theriogenology. 2024 Oct 15;228:75-80. doi: 10.1016/j.theriogenology.2024.08.001. Epub 2024 Aug 2.
In humans' and experimental animals' components of the somatotropic axis, such as growth hormone (GH) and insulin-like growth factor 1 (IGF-1) concentrations, decrease with advancing age. Although there is evidence regarding IGF-1, the effect of age on GH in mares, as well as the relationships between both parameters, have not yet been elucidated. On the other hand, although GH and IGF-1 are related to follicular development, it is unknown if they could be correlated with the circulating concentrations of ovarian steroids in mares, as occurs in other species. The hypothesis of this study was that both GH and IGF-1 could experience physiological changes with advancing age also in mares, and that both GH/IGF-1 could be correlated with oestradiol-17β (E) and progesterone (P), as recorded for other species. Hence, the objective of this study was to evaluate the concentrations of GH, IGF-1, E, and P in mares, according to the different ages. Blood samples were drawn from 56 healthy cyclic Spanish Purebred mares belonging to four different age groups: 6-9 years, 10-13 years, 14-16 years and >16 years. Mares aged 6-9 years and 10-13 years showed higher GH concentrations (P < 0.05) than mares of 14-16 and >16 years; and mares aged 14-16 showed higher GH concentrations (P < 0.05) than >16 years (P < 0.05). Mares aged >16 years showed lower IGF-1 concentrations (P < 0.05) than mares of 6-9, 10-13 and 14-16 years (P < 0.05). The concentrations of E and P showed no significant differences among different age groups. Both GH and IGF-1 were not correlated with each other or with E and P. The concentrations of E and P4 did not change with age. Advancing age leads to a decrease in the activity of the somatotropic axis in physiological cyclic mares, represented by a significant GH reduction, which, however, was ascribed for IGF-1 exclusively to mares over 16 years of age, without alterations in steroid hormone patterns.
在人类和实验动物的生长激素轴（somatotropic axis）组成部分中，如生长激素（GH）和胰岛素样生长因子 1（IGF-1）浓度会随着年龄的增长而降低。尽管有关于 IGF-1 的证据，但马的 GH 随年龄的变化以及这两个参数之间的关系尚未阐明。另一方面，尽管 GH 和 IGF-1 与卵泡发育有关，但尚不清楚它们是否与马循环中的卵巢类固醇浓度相关，就像其他物种一样。本研究的假设是，GH 和 IGF-1 也可能随着年龄的增长而在马中经历生理变化，并且 GH/IGF-1 可能与其他物种记录的雌二醇-17β（E）和孕酮（P）相关。因此，本研究的目的是根据不同年龄评估 GH、IGF-1、E 和 P 在马中的浓度。从 56 匹健康的西班牙纯种循环母马中抽取血液样本，这些母马分为四个不同的年龄组：6-9 岁、10-13 岁、14-16 岁和>16 岁。6-9 岁和 10-13 岁的母马 GH 浓度较高（P<0.05），14-16 岁和>16 岁的母马 GH 浓度较低（P<0.05）；14-16 岁的母马 GH 浓度较高（P<0.05），而>16 岁的母马 GH 浓度较低（P<0.05）。>16 岁的母马 IGF-1 浓度较低（P<0.05），6-9 岁、10-13 岁和 14-16 岁的母马 IGF-1 浓度较高（P<0.05）。不同年龄组之间 E 和 P 的浓度没有差异。GH 和 IGF-1 之间彼此没有相关性，也与 E 和 P 没有相关性。E 和 P4 的浓度随年龄增长没有变化。随着年龄的增长，生理循环母马的生长激素轴活性下降，表现为 GH 显著减少，但这仅归因于 16 岁以上的母马，而甾体激素模式没有改变。
