| dc.description.abstract | In free-fed mice with progesterone tablet implants and in pseudopregnant
mice, an increase in food consumption usually accompanies the body weight
gain characteristic of progesterone stimulation; it is not, however, an essential
feature since mice on restricted food intakes show similar weight changes.
Increases in water consumption usually, but not invariably, accompany the
weight gain. The loss of weight after progesterone withdrawal or at the end
of pseudopregnancy is accompanied by a reduction in food and water consumed
as after parturition or pseudo-parturition.
Analyses of the weight gain in progesterone-treated mice with increased
food intakes revealed retention of water, fat and protein, together with an
increased total energy expenditure of about 10 per cent. Retention of water
and protein and increased energy expenditure still occurred with the food intake
restricted to submaintenance levels, i.e. even in the presence of continuous losses
of body fat.
It is concluded that progesterone fundamentally affects body weight by
promoting water and nitrogen retention and, at the same time, increasing energy
expenditure. The increase in food intake usually observed is, at le4st in part,
a secondary response to the demands created by the latter two effects and fat
deposition occurs also if this response is overadjusted. | |
