第2个回答 2009-10-13
ADH嘛。
当在血液中的water potential increases 的时候,血液中的receptors就会send message to the axon of the nerve cell. the nerve cell's cell body secretes ADH , send ADH to the axon and then into the blood. ADH can make the membrane of the collecting duct in kidney become more permeable for the water and urea. in this case, water osmosises out of the collecting duct and then is reassorbed by the body; urea is given out of the collecting duct to decrease the concentration of the solute and so increase the water potential in the collecting duct. thus more water diffuses out of the collecting duct and less water is lost. 这样尿量减少。