Influence of diet and obesity on placental amino acid enzyme activities in the rat.

The objective of this study was to assess the impact of dietary obesity and acute starvation on the activity of placental enzymes involved in amino acid metabolism. Twenty-four hours starvation caused a significant fall (10%) in the foetal weight in rats fed standard diet, and this was associated with only modest changes in amino acid enzyme activities. In contrast, in obese rats, foetal weight was unaffected by acute starvation, and was accompanied by a reduced adenylate deaminase activity (24%) and lower ammonia concentrations (50%) in placentae of obese rats after 24h starvation. Thus obesity may confer a protective effect on the foetus growth during acute starvation of diminishing amino acid utilization.