Influences of maternal caffeine on the neonatal rat brains vary with the nutritional states.

The potential effect of maternal caffeine ingestion upon total brain protein and the concentration of two prototype neuropeptides, thyrotropin-releasing hormone (TRH) and its derivative, cyclo (His-Pro) in neonates was examined during the nursing period in the context of variable maternal protein intake. Maternal caffeine intake (2 mg/100 g body weight) significantly increased the total brain protein of neonates derived from dams fed a 6% casein diet, but not from dams fed a 12%- or 20%-casein diet. Maternal caffeine consumption significantly increased the amount of cyclo (His-Pro) in the neonatal brains in all groups. The percent increments in pups from dams fed 6%, 12%, and 20% casein diets were respectively 137%, 131%, and 120%. By contrast, no significant alterations were observed in TRH concentrations between caffeine and control groups. It is concluded that maternal caffeine can influence neonatal brain protein and cyclo (His-Pro) during nursing under conditions of protein-energy malnutrition.