Isolation of two arginine vasopressin-like factors from ganglia of Locusta migratoria

Tissues of Locusta migratoria are known to contain a material which crossreacts with an antibody against arginine vasopressin (AVP), and this factor has been correlated with the diuretic hormone of this species. In this paper, we report the isolation of two AVP-like factors from suboesophageal ganglia and thoracic ganglia of Locusta migratoria. The less abundant, more hydrophobic of these AVP-like factors shows diuretic activity in an assay where excretion of amaranth dye from Locusta migratoria hemolymph is used as the scoring criterion. After extracting a total of ～ 51,000 ganglia with an acidic solvent, the crude extract was prepurified by batch adsorption/elution from disposable reversed-phase cartridges. The prepurified extract was then sequentially purified by reversed-phase liquid chromatography using solvent programs of substantially differing selectivity. The more abundant factor was isolated to apparent homogeneity in three steps, while the less abundant factor required four or five steps. Use of a C₄ reversed-phase column minimized losses of the minor, more hydrophobic factor.