Persistent changes in central catecholaminergic system after recovery of perinatally undernourished rats.
Pregnant rats from day 14 of pregnancy or pups were fed a control diet (24% casein) or a deprived diet (8% casein) in order to obtain the following groups: 1) Control (C-C group); 2) Prenatal deprived (D-C group); 3) Postnatal deprived (C-D group); 4) Pre and postnatal deprived (D-D group). From 50 days of age on, all groups were fed a balanced commercial stock diet until 140 days of age. A significant reduction in corporal and brain weights was observed in C-D and D-D groups during deprivation and after nutritional recovery. Twenty-four day old deprived rats showed a decrease in brain noradrenaline (NA) content but no significant change in NA concentration. By the end of the deprivation period (50 days), brain NA levels tended to be reduced or increased in postnatal deprived rats, depending upon the method of expressing the results (microgram NA/whole brain or microgram NA/g fresh tissue, respectively). At 140 days of age, i.e., after 90 days of nutritional recovery, no differences were detected between deprived and control rats. However, conversion rate of [14C]tyrosine to brain catecholamines and tyrosine-hydoxylase activity were higher in D-D rats as compared with controls at this age. These results suggest that perinatal undernutrition produces, even after a prolonged period of nutritional recovery, a permanent activation of the central catecholaminergic system in adulthood. This fact may explain the different behavioral alterations described as a consequence of protein deprivation in early life.