Effect of undernutrition on GMP-PNP binding and adenylate cyclase activity from rat brain.

1. Undernutrition is an insult that affects brain development and functioning. Considering that signaling through metabotropic receptors/G proteins is critical for normal synaptic transmission and contributes to CNS development and synaptic plasticity, the present study investigated the effects of pre- and postnatal protein deprivation (diet: 8% protein; normonourished group: 25% protein) on brain signal transduction by G proteins. 2. Undernutrition decreased the [3H] GMP-PNP binding to G proteins and AC activity, in neural plasma synaptic membranes of 21- and 75-day-old rats. This effect was less pronounced or even absent in old rats. 3. Ontogenetically, the dietary treatment effect might be interpreted as a retarded development associated with protein malnutrition.