Hillyard S D, Hoff K S, Propper C
Department of Biological Sciences, University of Nevada, Las Vegas 89154-4004, USA.
Physiol Zool. 1998 Mar-Apr;71(2):127-38. doi: 10.1086/515900.
Terrestrial amphibians take up water by abducting the hind limbs and pressing a specialized portion of the ventral skin to a moist surface, using a characteristic behavior called the water absorption response. An assay of the water absorption response was used to quantify physiological factors associated with thirst and water uptake. Dramatic changes in the water absorption response resulted from subtle changes in hydration state and from altering the reserve water supply in the urinary bladder. The water absorption response could be induced by intraperitoneal and intracerebroventricular injection of angiotensin II, demonstrating that components of the renin-angiotensin system on both sides of the blood-brain barrier have a dipsogenic function in amphibians. These experiments also demonstrated that the water absorption response could be influenced by changes in barometric pressure. Toads avoided the water absorption response on hyperosmotic substrates, and behavioral experiments showed that the amphibian skin served a sensory function similar to that of the lingual epithelium of mammals. The water absorption response assay has enormous potential as a tool for the investigation of physiological processes and sensory capabilities of amphibians.
陆生两栖动物通过展开后肢并将腹部皮肤的特定部位压在潮湿表面来摄取水分，这一过程采用了一种名为吸水反应的独特行为。吸水反应测定法被用于量化与口渴和水分摄取相关的生理因素。吸水反应的显著变化源于水合状态的细微改变以及膀胱储备水量的变化。腹腔注射和脑室内注射血管紧张素 II 均可诱发吸水反应，这表明血脑屏障两侧的肾素 - 血管紧张素系统成分在两栖动物中具有致渴功能。这些实验还表明，吸水反应会受到气压变化的影响。蟾蜍在高渗底物上会避免吸水反应，行为实验表明，两栖动物的皮肤具有与哺乳动物舌上皮类似的感觉功能。吸水反应测定法作为研究两栖动物生理过程和感觉能力的工具具有巨大潜力。
