A rapid and simple micromethod to measure picograms of norepinephrine (NE) and dopamine (DA) in small samples of brain tissue and pituitary gland.

A rapid and simple procedure to determine Dopamine (DA) and Norepinephrine (NE) in small tissue samples (mug quantities) is described. The radioenzymatic assay sensitivity, defined as twice the blank, is about 0.1 ng for NE and DA. Drugs known to modify brain catecholamine metabolism were shown to alter differentially DA and NE concentration in the medial basal hypothalamus (MBH) of male rats. Different areas of the brain and the pituitary gland, namely the parietal cortex, the pre-optic region (POA), the median eminence (ME), the medial basal hypothalamus without the median eminence and the posterior pituitary contain different concentrations of DA and NE, emphasizing the importance of regional analyses in tissue amines determination.