Department of Veterinary Sciences, Biochemistry Unit, University of Messina, Polo Universitario dell'Annunziata, Messina, Italy.
Department of Clinical and Experimental Medicine, University of Messina, Policlinico Universitario, Messina, Italy.
J Equine Vet Sci. 2020 May;88:102969. doi: 10.1016/j.jevs.2020.102969. Epub 2020 Mar 2.
Serotonin (5-hydroxytryptamine [5-HT]) may induce metabolic effects in different cell types, including leukocytes. In horses, 5-HT is involved in physiological and behavioral functions. Physical exercise is known to increase the amounts of 5-HT both in brain and periphery, but so far, the signal mechanism in response to exercise is not known. The aim of the study was to investigate the effect of a racehorse intensive training session on plasma 5-HT levels, serotonin transporter (SERT), 5HT, 5-HT, 5-HT, 5-HT receptor, interleukin-1 beta, and tumor necrosis factor-alpha expression in horse peripheral blood mononuclear cells (PBMC). In particular, the research was carried out on 12 trained horses performing daily training. Plasma 5-HT levels were analyzed in platelet-poor plasma fraction by enzyme-linked immunosorbent assay at T0, T1, and T2 (pretraining, 30 minutes post-training, and 2 hours post-training session), respectively. Peripheral blood mononuclear cells were isolated to perform real-time polymerase chain reaction for the evaluation of SERT, 5-HT receptor, and cytokine mRNA levels. The results showed significantly increased levels of plasma 5-HT, 5HT, and 5-HT and significantly decreased levels of SERT, 5-HT, 5-HT, and both cytokine mRNAs in PBMC at T1, compared with T0 and T2. The results were confirmed by in vitro experiment. Training may induce a lower degree of 5-HT storage and, therefore, a higher plasma 5-HT concentrations. Leukocyte 5-HT receptor mRNAs seem strongly influenced by the exercise. Observed changes suggest a transient neuroendocrinological response to the exercise. A better understanding of the influence of physical exercise on serotoninergic system could have potential application for the implementation of training protocols in racing horses.
血清素（5-羟色胺[5-HT]）可能会在不同的细胞类型中诱导代谢效应，包括白细胞。在马中，5-HT 参与生理和行为功能。已知运动可以增加大脑和外周血中的 5-HT 含量，但到目前为止，运动的信号机制尚不清楚。本研究旨在研究赛马强化训练对马外周血单个核细胞（PBMC）中血浆 5-HT 水平、5-羟色胺转运体（SERT）、5-HT1A、5-HT2A、5-HT2C、5-HT7 受体、白细胞介素-1β和肿瘤坏死因子-α表达的影响。特别是，研究了 12 匹接受日常训练的训练有素的马。在 T0、T1 和 T2（训练前、训练后 30 分钟和 2 小时）分别通过酶联免疫吸附试验在血小板贫乏的血浆级分中分析血浆 5-HT 水平。分离外周血单个核细胞进行实时聚合酶链反应，以评估 SERT、5-HT 受体和细胞因子 mRNA 水平。结果显示，与 T0 和 T2 相比，T1 时 PBMC 中血浆 5-HT、5-HT 和 5-HT 水平显著升高，SERT、5-HT、5-HT 和两种细胞因子 mRNAs 水平显著降低。体外实验结果得到了证实。训练可能导致 5-HT 储存程度降低，从而导致血浆 5-HT 浓度升高。白细胞 5-HT 受体 mRNAs 似乎受到运动的强烈影响。观察到的变化表明对运动的短暂神经内分泌反应。更好地了解体育锻炼对 5-羟色胺能系统的影响可能对外套马的训练方案的实施具有潜在应用价值。
