In some species, catecholamines in follicular fluid (FF) are related to local physiological events responsible for the regulation of ovarian functions and oocyte maturation. The aim of the present study was to determine and compare intrafollicular and systemic concentrations of dopamine (DA), noradrenaline (NA) and adrenaline (AD) in cycling mares. Sixty ovaries were collected during breeding season from 30 mares raised for slaughterhouse meat production, with clinically normal reproductive tracts, were evaluated. Blood samples were collected prior to slaughter. Follicles were classified into three categories in relation to size: small (20–30 mm; n = 20), medium (≥31–40 mm; n = 20) and large (≥41 mm; n = 20). Follicular fluid (FF) samples were extracted from each follicle. Intrafollicular DA, NA and AD concentrations were significantly higher than the systemic concentrations (p < 0.05). Intrafollicular DA concentrations were higher in medium than small and large follicles (p < 0.05). Intrafollicular NA concentrations were higher in small than medium and large follicles (p < 0.05). Intrafollicular AD concentrations were higher in large than small and medium follicles (p < 0.05). Follicle diameter was significantly and negatively correlated with NA and AD (p < 0.05). A significant correlation of the same hormone concentration in FF and in systemic fluid was observed (p < 0.05). In summary, the FF can serve as an intraovarian catecholamine-storing compartment, with the ability to release neurotransmitters in a regulated way. These results provide novel insights into the neuronal nature of the follicle, suggesting the involvement of catecholamines in normal ovarian functions in mares.

中文翻译：

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骑行母马的卵泡内和全身多巴胺，去甲肾上腺素和肾上腺素浓度

在某些物种中，卵泡液（FF）中的儿茶酚胺与负责调节卵巢功能和卵母细胞成熟的局部生理事件有关。本研究的目的是确定和比较骑行母马的多巴胺（DA），去甲肾上腺素（NA）和肾上腺素（AD）的卵泡内和全身浓度。在繁殖季节，从30只母马中收集了60头卵巢，这些母猪用于生产屠宰场的肉，并具有临床正常的生殖道。屠宰前要采集血样。相对于大小，卵泡分为三类：小（20–30 mm；n = 20），中等（≥31–40 mm；n = 20）和大（≥41mm；n= 20）。从每个卵泡中提取卵泡液（FF）样品。滤泡内DA，NA和AD浓度显着高于全身浓度（p <0.05）。中，小卵泡中DA的浓度高于大卵泡（p <0.05）。小卵泡中NA的浓度高于中大卵泡（p <0.05）。大卵泡中的卵泡内AD浓度高于中小卵泡（p <0.05）。卵泡直径与NA和AD呈显着负相关（p <0.05）。FF和体液中相同激素浓度之间存在显着相关性（p<0.05）。总之，FF可以充当卵巢内儿茶酚胺储存区室，并具有以受控方式释放神经递质的能力。这些结果提供了关于卵泡神经元性质的新颖见解，表明儿茶酚胺参与了母马的正常卵巢功能。