Tyrosine hydroxylase activity in brain regions after intraventricular 6-hydroxydopamine in the neonatal rat

Intraventricular 6-OHDA treatment to newborn rats produced a marked reduction in tyrosine hydroxylase activity in most brain regions at maturity which correlated moderately well with the catecholamine levels. However, those regions in which NE levels were increased did not show a corresponding increase in total tyrosine hydroxylase activity. There was a much better correlation between NE levels and the particulate form of tyrosine hydroxylase which has been suggested to be the more functionally active form of the enzyme.