Evaporative water loss from rats in the heat

Abstract

In rats, the heat water lost through saliva is the major component of evaporative water loss. Total evaporative water loss was measured from normal and desalivated rats, and salivary evaporative water loss was estimated as the difference in evaporation between the normal and desalivated rats. Above 32''C, the salivary evaporation gradually increased up to 44[degree]C which was the highest experimental temperature. At 44[degree]C males and females evaporated similar amounts, but below 44[degree]C males evaporated more salivary water. In desalivated rats evaporative water loss was smaller, but it increased with ambient temperature. Comparisons are made with other rodents, and water losses are related to other responses reported for rats under heat stress.