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. 2023 Oct 1;209:178-183. doi: 10.1016/j.theriogenology.2023.06.027. Epub 2023 Jun 28.
In woman and in animal models, estrogens are involved in iron (Fe) homeostasis supporting the hypothesis of the existence of an "estrogen-iron axis". Since advancing age leads to a decrease in estrogen levels, the mechanisms of Fe regulation could be compromised. In cyclic and pregnant mares, to date, there is evidence linking the iron state with estrogens pattern. Then, the objective of this study was to determine the relationship among Fe, ferritin (Ferr), hepcidin (Hepc) and estradiol-17β (E) in cyclic mares with advancing age. A total of 40 Spanish Purebred mares of different ranges of age was analyzed: 4-6 years (n = 10), 7-9 years (n = 10), 10-12 years (n = 10), and >12 years (n = 10). Blood samples were obtained on days -5, 0, +5 and + 16 of the cycle. Compared to mares of 4-6 years, serum Ferr was significantly higher (P < 0.01) and Fe significantly lower (P < 0.01) in mares >12 years of age. Hepc was significantly higher in mares >12 years (P < 0.01) than in those 7-9 years of age. E levels were higher in mares of 7-9 years (P < 0.01) than in 4-6 and >12 years of age. Fe and Ferr were negatively correlated with Hepc (r = -0.71 and r = -0.02, respectively). E was negatively correlated with Ferr and Hepc (r = -0.28 and r = -0.50, respectively), and positively with Fe (r = 0.31). There is a direct relationship between E and Fe metabolism, mediated by the inhibition of Hepc in Spanish Purebred mares. The reduction of E decreases the inhibitory effects on Hepc, increasing the levels of stored Fe and mobilizing less the free Fe in circulation. Based on the fact that ovarian estrogens participate in changes in the parameters indicative of iron status with age, the existence of an "estrogen-iron axis" in the mares'estrous cycle could be considered. Future studies are required to clarify these hormonal and metabolic interrelationships in the mare.
在女性和动物模型中，雌激素参与铁（Fe）稳态的调节，支持“雌激素-铁轴”假说的存在。由于随着年龄的增长，雌激素水平下降，因此铁调节的机制可能会受到影响。迄今为止，在循环和妊娠母马中，有证据表明铁状态与雌激素模式有关。那么，本研究的目的是确定衰老西班牙纯种母马中 Fe、铁蛋白（Ferr）、hepcidin（Hepc）和雌二醇-17β（E）之间的关系。分析了不同年龄段的 40 匹西班牙纯种母马：4-6 岁（n=10）、7-9 岁（n=10）、10-12 岁（n=10）和>12 岁（n=10）。在周期的-5、0、+5 和+16 天采集血液样本。与 4-6 岁的母马相比，>12 岁的母马血清 Ferr 显著升高（P<0.01），Fe 显著降低（P<0.01）。>12 岁的母马 Hepc 显著升高（P<0.01）。7-9 岁的母马 E 水平明显高于 4-6 岁和>12 岁的母马（P<0.01）。Fe 和 Ferr 与 Hepc 呈负相关（r=-0.71 和 r=-0.02）。E 与 Ferr 和 Hepc 呈负相关（r=-0.28 和 r=-0.50），与 Fe 呈正相关（r=0.31）。在西班牙纯种母马中，E 与 Fe 代谢之间存在直接关系，这是由 Hepc 的抑制介导的。E 的减少降低了对 Hepc 的抑制作用，增加了储存铁的水平，并减少了循环中游离铁的动员。鉴于卵巢雌激素参与了随着年龄变化的铁状态参数的变化，因此可以认为“雌激素-铁轴”在母马发情周期中存在。需要进一步的研究来阐明母马中这些激素和代谢的相互关系。
