We have investigated the effects of substrate-bound laminin on levels of enzymes of the catecholamine biosynthetic pathway in primary cultures of calf adrenal chromaffin cells. Laminin increases the levels of the enzymes tyrosine hydroxylase, dopamine-beta-hydroxylase, and phenylethanolamine-N-methyl-transferase. This effect is selective, in that levels of other enzymes (lactate dehydrogenase, ...

THE CoNVERsIoN of tyrosine to 3,~dihydroxyphenylal~ine by the enzyme, tyrosine hydroxylase appears to be the ratedetermining step in the biosynthesis of norepinephrine.1 Thus this enzyme is the focal point for possible physiological and pharmacological control of norepinepbrine synthesis. A relatively largenumber of compounds have been shown to be inhibitors of tyrosine hydroxylase.2-5 These ge...

Mice carrying mutant amyloid-β precursor protein and presenilin-1 genes (APP/PS1 double transgenic mice) have frequently been used in studies of Alzheimer's disease; however, such studies have focused mainly on hippocampal and cortical changes. The severity of Alzheimer's disease is known to correlate with the amount of amyloid-β protein deposition and the number of dead neurons in the locus co...

Tyrosinase (EC 1.14.18.1) is a copper-containing metalloglycoprotein that catalyzes several steps in the melanin pigment biosynthetic pathway; the hydroxylation of tyrosine to L-3,4-dihydroxyphenylalanine (dopa) and the subsequent oxidation of dopa to dopaquinone. It has been proposed that tyrosinase is also able to oxidize 5,6-dihydroxyindole (DHI), a later product in the melanogenic pathway, ...