Coelho Lia Alencar, Silva Luciano Andrade, Reway Ana Paula, Buonfiglio Daniella Do Carmo, Andrade-Silva Jéssica, Gomes Patrícia Rodrigues Lourenço, Cipolla-Neto José
Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of São Paulo, Pirassununga 13635-900, Brazil.
Department of Physiology and Biophysics, Institute of Biomedical Sciences (ICB), University of São Paulo, São Paulo 05508-000, Brazil.
Animals (Basel). 2023 Mar 15;13(6):1063. doi: 10.3390/ani13061063.
This study investigated the seasonal variations in mRNA expression of FSH (), LH () receptors, melatonin ( and ) receptors, melatonin-synthetizing enzymes ( and ) and melatonin concentration in developing follicles from mares raised in natural photoperiods. For one year, ultrasonographic follicular aspiration procedures were performed monthly, and small (<20 mm), medium (20 to 35 mm) and large (>35 mm) follicles were recovered from five mares. One day before monthly sample collections, an exploratory ultrasonography conducted to record the number and the size of all follicles larger than 15 mm. The total number of large follicles were higher during the spring/summer (8.2 ± 1.9) than during autumn/winter (3.0 ± 0.5). Compared to autumn/winter seasons, there was an increase of and mRNA expressions in small, medium and large follicles, an increase of and mRNA expressions in medium and large follicles and an increase of and mRNA expressions in small and large follicles during spring/summer. The melatonin levels in follicular fluid were also higher during the spring/summer seasons. The present data show that melatonin locally upregulates the mRNA expression of and receptors and melatonin-forming enzymes in mare developing follicles during reproductive seasons.
本研究调查了在自然光照周期下饲养的母马发育卵泡中促卵泡激素（FSH）、促黄体生成素（LH）受体、褪黑素（MT1和MT2）受体、褪黑素合成酶（AANAT和HIOMT）的mRNA表达以及褪黑素浓度的季节性变化。在一年的时间里，每月进行超声引导下的卵泡抽吸手术，从5匹母马中采集小（<20 mm）、中（20至35 mm）和大（>35 mm）卵泡。在每月样本采集前一天，进行一次探索性超声检查，记录所有大于15 mm卵泡的数量和大小。春季/夏季大卵泡的总数（8.2±1.9）高于秋季/冬季（3.0±0.5）。与秋季/冬季相比，春季/夏季小、中、大卵泡中MT1和MT2的mRNA表达增加，中、大卵泡中AANAT和HIOMT的mRNA表达增加，小、大卵泡中MT1和HIOMT的mRNA表达增加。春季/夏季卵泡液中的褪黑素水平也较高。目前的数据表明，在繁殖季节，褪黑素在局部上调母马发育卵泡中MT1和MT2受体以及褪黑素形成酶的mRNA表达。
