Ethanol administration in the drinking fluid to pregnant rats as a model for the fetal alcohol syndrome.

Addition of ethanol (ET) to the drinking fluid of pregnant rats has been questioned as an experimental model for the fetal alcohol syndrome (FAS). This model, however, closely simulates human alcohol intake, and in this study we used a modified version of previous protocols to overcome their major defects. A group of female rats was given 10% ET in drinking fluid for one week, 15% for the second week, 20% for the third, and 25% for the fourth, at the end of which they were mated with non-treated males and given 25% ET throughout gestation. Three groups of non-ET treated sex and age-matched rats were studied in parallel: (1) normal controls receiving solid diet ad lib, (2) paired fed rats, and (3) rats fed ad lib the solid diet mixed with 50% fiber. In the ET group, food intake decreased as ET consumption augmented, the ET calories comprising over 30% of the total energy intake during pregnancy. Total energy intake was similar for ET group and normal controls, and was higher than in paired fed animals or those on 50% fiber diet. Body weight gain in ET rats was similar to those on 50% fiber diet, lower than in normal controls and higher than in paired fed animals. At the 21st day of gestation, rats on ET had plasma ethanol levels of 147 +/- 18 mg/dl and higher plasma osmolality than in the other groups studied. In ET rats, fetal body weight was lower than in either normal controls or rats on 50% fiber diet, and fetal body length was shorter than in any other group.(ABSTRACT TRUNCATED AT 250 WORDS)