Measurement of catecholamines, indoleamines, thyrotrophin releasing hormone and substance P in rat and human spinal cord using a common extraction method

An extraction method is described that allows the measurement of 5-hydroxyindoleacetic acid, dopamine, noradrenaline, substance P and thyrotrophin releasing hormone in the same sample of rat or human spinal cord. The substances were extracted using a mixture of 45% ethanol/0.1 M acetic acid and 0.02% sodium metabisulphite. The amines were then measured using high performance liquid chromatography with electrochemical detection and the peptides by radioimmunoassay. The common extraction method makes maximum use of limited postmortem material, reduces assay time and allows study of the interrelationships between the amines and peptides in rat or human spinal cord.