Abstract: The invention provides an isolated nucleic acid encoding the rat P450 2C11 arachidonic acid epoxygenase, or a human homologue thereof, having a mutation associated with salt induced hypertension. Also provided is an isolated cell line expressing the epoxygenase encoded by the mutated nucleic acid, and a non-human transgenic animal having a germ line insertion of the mutated nucleic acid. Also provided is a method of screening a compound for efficacy in treating salt induced hypertension comprising administering the compound to such a non-human transgenic animal, and detecting an improvement in the animal's hypertension. The invention also provides a method of screening a human subject for a genetic predisposition to salt induced hypertension comprising detecting a mutation in a human homologue of a rat P450 2C11 arachidonic acid epoxygenase gene which affects normal epoxygenase activity.