Effect of central early postnatal 6 hydroxydopamine administration on brain catecholamines and pituitary adrenal function in adulthood

Central administration of 6 hydroxydopamine (60HDA) to newborn rats induced a dose dependent and long lasting decrease in noradrenaline (NA) and dopamine (DA) content in adult male and female rat brain. After postnatal administration of 100 μg 60HDA, a decrease of about 50% of NA and DA content of the whole brain was found in 9 to 10 wk old rats; 200 μg 60HDA induced a reduction of 80% of NA and DA content. The latter treatment was followed by a severe growth retardation, a marked myosis, a decrease in general activity, and disappearance of clonic convulsions after decapitation. At the same time, however, in both groups of animals no change in basal pituitary adrenal activity was found, as evaluated by measurement of corticosterone in plasma, in vitro adrenal corticoid production, and adrenal weight. Apparently even severe inhibition of the development of central DA and NA systems by 60HDA administration to the newborn rat did not induce any change in basal pituitary adrenal functioning.