Abstract：
BACKGROUND: Eugenol is the most commonly used plant anesthetic to relieve the stressors during various aquaculture procedures. This study aims to investigate the pharmacokinetics of eugenol in Pacific white shrimp by immersion baths in a simulated transportation.
RESULTS: The pharmacokinetics of eugenol were firstly investigated in Pacific white shrimp by immersion baths of 300 mg L- 1 eugenol over 5 min (Treatment 1), 10 mg L- 1 eugenol during 24 h (Treatment 2) and a sequential immersion administration (Treatment 3). Concentrations of eugenol in hemolymph, hepatopancreas, and muscle were determined using Gas chromatography-tandem mass spectrometry (GC-MS/MS). After immersion bath of Treatment 1, the elimination half-life (t1/2z) values are 1.3 h and 11 h for hepatopancreas and muscles, indicating the rapid absorption and elimination of eugenol in shrimp. Under the Treatment 2 administration, the eugenol peak concentration is 6527.9 μg/kg in muscle, followed by 402.8 μg/kg in hepatopancreas, with the lowest concentration of 37.9 μg/L in hemolymph. Area under the curve (AUC0-∞) values lie in the order of muscle > hepatopancreas > hemolymph, suggesting that eugenol tends to accumulate in muscle by the immersion administration. Moreover, the average residence time (MRT0-∞) values of 38.6, 23.0 and 115.3 h for hemolymph, hepatopancreas and muscle are achieved, which may indicate that hepatopancreas is the main organ for elimination of eugenol. After combining the conditions in a sequential bath immersion of eugenol (Treatment 3), the maximum concentration (Cmax) values of eugenol are higher than those achieved in Treatment 2, indicating that accumulation of eugenol happened in haemolymph, hepatopancreas and muscle. In addition, the corresponding t1/2z values are 4.7, 14.9 and 47.6 h, respectively, suggesting the faster elimination from the tissues following sequential administration. After the immersion bath, eugenol concentrations in muscle of Pacific white shrimp are lower than 2.5 mg/kg at 2 h, 48 h and 24.5 h in Treatment 1 ~ 3.
CONCLUSIONS: A withdrawal period of 2 h, 48 h and 24.5 h following a 300 mg L- 1 of eugenol over a 5-min, 10 mg L- 1 eugenol concentration during a 24-h and combined conditions in a sequential immersion bath were suggested.
RESULTS: The pharmacokinetics of eugenol were firstly investigated in Pacific white shrimp by immersion baths of 300 mg L- 1 eugenol over 5 min (Treatment 1), 10 mg L- 1 eugenol during 24 h (Treatment 2) and a sequential immersion administration (Treatment 3). Concentrations of eugenol in hemolymph, hepatopancreas, and muscle were determined using Gas chromatography-tandem mass spectrometry (GC-MS/MS). After immersion bath of Treatment 1, the elimination half-life (t1/2z) values are 1.3 h and 11 h for hepatopancreas and muscles, indicating the rapid absorption and elimination of eugenol in shrimp. Under the Treatment 2 administration, the eugenol peak concentration is 6527.9 μg/kg in muscle, followed by 402.8 μg/kg in hepatopancreas, with the lowest concentration of 37.9 μg/L in hemolymph. Area under the curve (AUC0-∞) values lie in the order of muscle > hepatopancreas > hemolymph, suggesting that eugenol tends to accumulate in muscle by the immersion administration. Moreover, the average residence time (MRT0-∞) values of 38.6, 23.0 and 115.3 h for hemolymph, hepatopancreas and muscle are achieved, which may indicate that hepatopancreas is the main organ for elimination of eugenol. After combining the conditions in a sequential bath immersion of eugenol (Treatment 3), the maximum concentration (Cmax) values of eugenol are higher than those achieved in Treatment 2, indicating that accumulation of eugenol happened in haemolymph, hepatopancreas and muscle. In addition, the corresponding t1/2z values are 4.7, 14.9 and 47.6 h, respectively, suggesting the faster elimination from the tissues following sequential administration. After the immersion bath, eugenol concentrations in muscle of Pacific white shrimp are lower than 2.5 mg/kg at 2 h, 48 h and 24.5 h in Treatment 1 ~ 3.
CONCLUSIONS: A withdrawal period of 2 h, 48 h and 24.5 h following a 300 mg L- 1 of eugenol over a 5-min, 10 mg L- 1 eugenol concentration during a 24-h and combined conditions in a sequential immersion bath were suggested.
摘要：
背景：丁香酚是最常用的植物麻醉剂，可在各种水产养殖过程中缓解压力。本研究旨在研究丁香酚在太平洋白虾中的药代动力学。
结果：首先通过300mgL-1丁香酚浸浴5分钟（治疗1）研究了丁香酚在太平洋白虾中的药代动力学，10mgL-1丁香酚在24小时内(治疗2)和顺序的浸没给药(治疗3)。血淋巴中丁香酚的浓度,肝胰腺,和肌肉使用气相色谱-串联质谱法(GC-MS/MS)测定。处理1浸泡浴后，肝胰腺和肌肉的消除半衰期（t1/2z）值为1.3h和11h，说明丁香酚在虾中的快速吸收和消除。在治疗2的管理下，丁香酚在肌肉中的峰值浓度为6527.9μg/kg，其次是肝胰腺中的402.8μg/kg，血淋巴中的最低浓度为37.9μg/L。曲线下面积（AUC0-∞）值的顺序为肌肉>肝胰腺>血淋巴，这表明丁香酚倾向于通过浸没给药在肌肉中积累。此外，血淋巴的平均停留时间(MRT0-∞)为38.6、23.0和115.3h，肝胰腺和肌肉，这可能表明肝胰腺是消除丁香酚的主要器官。在丁香酚的顺序浴浸（处理3）中组合条件后，丁香酚的最大浓度（Cmax）值高于治疗2中达到的值，表明丁香酚的积累发生在血淋巴中，肝胰腺和肌肉。此外,相应的t1/2z值为4.7、14.9和47.6h，分别,提示顺序给药后更快地从组织中消除。浸浴后，太平洋白虾肌肉中丁香酚的浓度在2小时低于2.5mg/kg，处理1~3的48h和24.5h。
结论：停药期为2小时，在5分钟内服用300mgL-1丁香酚后48小时和24.5小时，建议在24小时内使用10mgL-1丁香酚浓度，并在连续浸入浴中进行组合。
结果：首先通过300mgL-1丁香酚浸浴5分钟（治疗1）研究了丁香酚在太平洋白虾中的药代动力学，10mgL-1丁香酚在24小时内(治疗2)和顺序的浸没给药(治疗3)。血淋巴中丁香酚的浓度,肝胰腺,和肌肉使用气相色谱-串联质谱法(GC-MS/MS)测定。处理1浸泡浴后，肝胰腺和肌肉的消除半衰期（t1/2z）值为1.3h和11h，说明丁香酚在虾中的快速吸收和消除。在治疗2的管理下，丁香酚在肌肉中的峰值浓度为6527.9μg/kg，其次是肝胰腺中的402.8μg/kg，血淋巴中的最低浓度为37.9μg/L。曲线下面积（AUC0-∞）值的顺序为肌肉>肝胰腺>血淋巴，这表明丁香酚倾向于通过浸没给药在肌肉中积累。此外，血淋巴的平均停留时间(MRT0-∞)为38.6、23.0和115.3h，肝胰腺和肌肉，这可能表明肝胰腺是消除丁香酚的主要器官。在丁香酚的顺序浴浸（处理3）中组合条件后，丁香酚的最大浓度（Cmax）值高于治疗2中达到的值，表明丁香酚的积累发生在血淋巴中，肝胰腺和肌肉。此外,相应的t1/2z值为4.7、14.9和47.6h，分别,提示顺序给药后更快地从组织中消除。浸浴后，太平洋白虾肌肉中丁香酚的浓度在2小时低于2.5mg/kg，处理1~3的48h和24.5h。
结论：停药期为2小时，在5分钟内服用300mgL-1丁香酚后48小时和24.5小时，建议在24小时内使用10mgL-1丁香酚浓度，并在连续浸入浴中进行组合。
