Abstract
To study the effects of dietary composition and chronic ethanol ingestion on plasma proteinase inhibitor (PI) levels in intact animals, 192 male Wistar rats were divided into 4 groups, which received a standard diet (S), a fat-rich diet (F), a protein-rich diet (P), and a carbohydrate-rich diet (C), respectively, for 12 weeks. Half of the animals in each diet group had 15% ethanol as their drinking solution (A) during this diet period, and the rest drank tap water (W). FW and CW diets caused a significant decrease in the trypsin-inhibiting capacity (TIC) of plasma in comparison with the SW group (p < 0.05 and p < 0.001, respectively), and chronic ethanol ingestion in combination with P and C diets decreased plasma TIC levels significantly (p < 0.01 and p < 0.001) when compared with the corresponding water-drinking groups. The chymotrypsin-inhibiting capacity (CIC) of plasma behaved differently: in the FW, PW, and CW groups it was significantly higher than in the SW group (p < 0.001). Chronic ethanol ingestion did not change plasma CIC levels significantly when compared with the corresponding water-receiving groups. In conclusion, dietary intake was found to alter plasma PI levels. Changes in the protein synthesis of the liver might be responsible for these alterations.