A rodent water dispensing system for use in hypobaric chambers.

Abstract : A water dispensing system for rodents has been developed for use in chronic research studies involving hypobaric chambers. The system removes an existing problem that has restricted long-term animal exposures due to limitations inherent in the typical water supply bottles. The bottle design used in previous systems makes it susceptible to leakage whenever the water surface tension is disturbed. This disturbance occurs when water or room temperatures change, when animals are drinking, or more dramatically when the barometric pressure changes during ascents to altitude. Exposed water on the chamber floor may produce secondary health and environmental concerns. Daily returns to sea level to replenish drinking water and clean the chamber become the only available solution but add a complicating research variable. With the present water dispensing system, water may be replenished on-line for indefinite operations; water is available to rodent ad libitum, independent of the pressure differential without leakage; the system is insensitive to water pressure and malfunctions due to mineral deposits; the amount of water consumed can be measured; and medications, drugs and vitamins may be administered.