Instituto de Recursos Biológicos, Centro de Investigaciones de Recursos Naturales (CIRN), Centro Nacional de Investigaciones Agropecuarias (CNIA), Instituto Nacional de Tecnología Agropecuaria (INTA), 1686, Hurlingham, Buenos Aires, Argentina.
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
Environ Sci Pollut Res Int. 2020 May;27(14):17152-17161. doi: 10.1007/s11356-020-08313-2. Epub 2020 Mar 7.
In the context of the global amphibian crisis, biomonitoring constitutes a valuable assessment tool to provide critical up to date information on the status and health of amphibians worldwide. The aim of the current study was to evaluate the possible confounding effects of sex, size, and time since capture on enzymatic biomarkers and hematologic parameters of the South American frog Leptodactylus latrans. Frogs were collected by hand between 9 pm and 12 am on two consecutive nights. On the first night, captured frogs were transported for 2 h by car to laboratory installations, maintained overnight in plastic containers, and blood and tissue sampled on the next morning. In contrast, frogs collected on the second night were blood and tissue sampled in the field, immediately after the capture period. Hematological parameters were analyzed, and enzymatic activities of catalase, cholinesterase (ChE), and glutathione S-transferase (GST) were determined in the plasma, liver, kidney, and muscle. A sex difference was observed only for total white blood cell counts (WBC), females exhibiting significantly greater values than males. The packed cell volume (PCV), mean corpuscular hemoglobin concentration (MCHC), WBC, and muscle ChE activity were significantly correlated with snout-vent length (SVL). The correlation was inversed in the case of MCHC, WBC, and muscle ChE, while the correlation was positive between PCV and SVL. Most examined parameters presented similar values when frogs were sampled at night following capture or the next morning. Total red blood cells (RBCs) count, and plasma enzymatic activities of ChE and GST were the only parameters that presented significantly increased values in morning samplings compared with night samplings. Overall, the current study indicates that it is best to sample the frogs as soon as possible after capture if hematologic or plasmatic biomarkers are examined. Nevertheless, it is possible to sample on the next morning if tissular biomarkers are employed.
在全球两栖动物危机的背景下，生物监测是一种有价值的评估工具，可以提供全球范围内两栖动物状况和健康的最新关键信息。本研究的目的是评估性别、大小和捕获后时间对南美青蛙 Leptodactylus latrans 的酶生物标志物和血液学参数的可能混杂影响。青蛙在连续两个晚上的 9 点至 12 点之间用手采集。在第一个晚上，捕获的青蛙被汽车运输 2 小时到实验室设施，在塑料容器中过夜保存，并在第二天早上进行血液和组织采样。相比之下，在第二个晚上收集的青蛙在捕获期后立即在现场进行血液和组织采样。分析血液学参数，并在血浆、肝脏、肾脏和肌肉中测定过氧化氢酶、胆碱酯酶 (ChE) 和谷胱甘肽 S-转移酶 (GST) 的酶活性。仅观察到总白细胞计数 (WBC) 存在性别差异，雌性的数值显著高于雄性。红细胞压积 (PCV)、平均红细胞血红蛋白浓度 (MCHC)、WBC 和肌肉 ChE 活性与吻肛长 (SVL) 显著相关。在 MCHC、WBC 和肌肉 ChE 的情况下，相关性呈反向，而在 PCV 与 SVL 之间，相关性呈正向。当青蛙在捕获后当晚或次日早上采样时，大多数检查的参数呈现相似的值。与夜间采样相比，红细胞总数 (RBC) 计数以及血浆 ChE 和 GST 的酶活性仅在早上采样时呈现出显著增加的值。总体而言，如果检查血液学或血浆生物标志物，最好在捕获后尽快采样青蛙。然而，如果使用组织生物标志物，则可以在第二天早上采样。
