Is noradrenaline a major catecholamine in the bovine retina?

Using high performance liquid chromatography (HPLC) and electrochemical detection, a major substance corresponding to noradrenaline was identified in crude perchloric acid extracts from bovine retina. Prior purification of the extract with aluminium oxide followed by HPLC confirmed this observation. By altering the oxidation potential of the detector, noradrenaline was confirmed by a further criterion. Bovine retina was also shown to metabolize [3H]dopamine to form a substance which was identified as noradrenaline by the same criteria used to establish its presence. The noradrenaline content was found to be 62 +/- 4 ng/g fresh weight of tissue. Its level is therefore of the same order as the dopamine content (86 +/- 3 ng/g fresh weight).