Kröber Thomas, Kessler Sébastien, Frei Jérôme, Bourquin Martine, Guerin Patrick M
Laboratory of Animal Physiology, Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland.
J Am Mosq Control Assoc. 2010 Dec;26(4):381-6. doi: 10.2987/10-6044.1.
We describe here an in vitro behavioral assay for testing mosquito repellents applied in a dose-based manner to a warm body (34 degrees C) in test cages. The system was used to assess the sensitivity of 4-6-day-old Anopheles gambiae to the insect repellent diethyl methyl benzamide (deet). These tests were made in the absence and presence of additional carbon dioxide (CO2) applied as a pulse to activate mosquitoes in the cages. In the absence of the CO2 pulse the mosquitoes hardly responded to the warm body. Increasing the CO2 level in the cage by 1,000 parts per million caused a 25-fold increase in the number of landings by mosquitoes on the warm body in 2-min tests. This mosquito activation allowed the measurement of a significant reduction in the number of landings to bite on the warm body with increasing doses of deet (0.4 to 3.8 microg/cm2). An asymptotic nonlinear model fitted to the repellency data in the presence of CO2 allowed estimation of the effective dose of deet that reduced landings to bite by 50% (ED50) at 0.95 microg/cm2 (5 nmol/cm2) and the corresponding ED95 at 4.12 microg/cm2 (21.5 nmol/cm2). This in vitro bioassay has the advantage of permitting a fast throughput of test products under standardized conditions and is suitable for screenings designed for the purpose of discovering lead products with as yet unknown human toxicological and dermatological profiles.
我们在此描述一种体外行为测定法，用于测试以剂量方式施用于测试笼中34摄氏度温体上的驱蚊剂。该系统用于评估4至6日龄冈比亚按蚊对驱虫剂二乙甲基苯甲酰胺（避蚊胺）的敏感性。这些测试在有和没有额外二氧化碳（CO₂）脉冲的情况下进行，CO₂脉冲用于激活笼中的蚊子。在没有CO₂脉冲的情况下，蚊子对温体几乎没有反应。在2分钟的测试中，将笼中的CO₂水平提高百万分之一千会使蚊子落在温体上的次数增加25倍。这种蚊子激活使得能够测量随着避蚊胺剂量增加（0.4至3.8微克/平方厘米），落在温体上叮咬的次数显著减少。在有CO₂存在的情况下，拟合驱避性数据的渐近非线性模型允许估计避蚊胺的有效剂量，即在0.95微克/平方厘米（5纳摩尔/平方厘米）时使落在温体上叮咬次数减少50%（ED50），以及在4.12微克/平方厘米（21.5纳摩尔/平方厘米）时对应的ED95。这种体外生物测定法的优点是能够在标准化条件下快速高通量测试产品，适用于旨在发现具有未知人体毒理学和皮肤病学特征的先导产品的筛选。
