PERINATAL UNDERNUTRITION AFFECTS BRAIN MODULATORY CAPACITY OF BETA-ADRENERGIC RECEPTORS IN ADULT-RATS

Rats submitted to a protein deprivation schedule from the perinatal period until 50 d of age (dams and/or rats fed an 8% casein diet) and then fed a commercial nonpurified diet for at least 90 d were assayed to evaluate the up- and down-regulation of β-adrenergic receptors in brain structures following prolonged (7 d) treatment with propranolol or desipramine, drugs that induce changes in receptor density. Propranolol produced up-regulation (increased B(max)) in the frontal cortex of both control and deprived animals, whereas desipramine treatment did not induce down-regulation in the frontal cortex or hippocampus of experimental rats, as it did in control rats. The lack of the down-regulation effect in response to desipramine treatment in deprived rats may be an alteration of adaptive mechanism, which may contribute to the behavioral abnormalities attributed to early undernutrition.