Long-term estrogenization in mammals. II. Environmental influences of housing conditions upon estrogen-induced polydipsia and food intake in Marsh mice.

Estrogen-induced polydipsia was influenced by environmental conditions in which Marsh mice were housed in plastic cages with bedding or in metal cages having grilled floors and no bedding. Increases in this polydipsia with metal-cage housing were reversed upon return to plastic. The increases over controls as ml/kg body weight ranged from 40 to 250%. After an initial fall in food consumption following estrogenization, controls and estrogenized mice consumed nearly the same amount of food/mouse but 10% more for the estrogenized mice on a g/kg body-weight basis. Increased food consumption for controls and estrogenized mice following the change from plastic to metal cages was attributed to compensation for increased loss of body heat. Whether in plastic or metal cages, core temperatures of controls were higher than those of estrogenized mice; both groups had relatively higher temperatures in the metal cages. The older mice in metal cages developed a gnawing pattern wasting food. In five experiments with males, body-weight losses following estrogenization were maintained 43 to 70 days but recovered in 2 of 4 experiments with females under comparable conditions.