Effects of dietary protein, fat and energy intake during an initiation phase study of @entity3653 -induced XXXX in @entity35 .

@entity3653 @entity0 @entity5 @entity4336 @entity106 @entity35 @entity105
A factorial experiment was conducted to examine the effects of dietary protein (8, 16, 32% of energy from casein) and dietary fat (12, 24, 48% of energy from @entity4336 oil) on the initiation of @entity3653 ( @entity106 )-induced @entity0 in @entity35 . Forty weanling female @entity35 were assigned to each of nine diets fed ad libitum. After 4 wk each @entity35 received @entity106 (20 mg/kg) via gastric intubation. For an additional 22 wk after carcinogen administration all @entity35 consumed a diet containing 16% of dietary energy from protein and 24% from fat. Dietary fat, protein and ad libitum energy consumption exhibited statistically significant effects on final @entity5 prevalence, but interactive effects were not found. At necropsy, @entity35 fed @entity4336 oil at 12, 24 and 48% of energy prior to @entity106 administration showed @entity5 prevalences of 58, 58 and 85% with 116, 153 and 231 total @entity5 , respectively. The data indicate a significant nonlinear effect of dietary fat. Corresponding numbers for @entity35 fed casein at 8, 16 and 32% of energy prior to @entity106 were prevalences of 79, 65 and 59%, with @entity5 counts of 194, 144 and 162. Higher dietary protein during the initiation phase was associated with a significant reduction in @entity5 prevalence, which was most striking between 8 and 16% of energy from protein. In addition, results of multiple logistic regression showed that tumorigenesis was increased with greater ad libitum energy intake. The odds of a @entity5 at necropsy were multiplied by 1.19 for each kilocalorie increase in ad libitum energy intake averaged over the post- @entity106 phase of the experiment. An additional six weanling @entity35 fed each diet for 4 wk were killed for assay of hepatic carcinogen metabolizing enzymes at the time corresponding to @entity106 administration in the initiation experiment. Both protein and fat showed independent effects on the activity of several enzymes. However, enzyme activity did not suggest a unifying mechanism whereby these nutrients influence @entity106 -induced mammary @entity105 .
