Biochemistry and Signalling Mechanism(s) of Imidazoline Receptors Imidazoline receptors are known to be implicated in several pathologies such as hypertension, depression and diabetes mellitus. Pharmacologically, they can be devided in at least two subgroups: I1 and I2 receptors. The blood pressure lowering potencies of a series of imidazolines corresponds to the pharmacological profile of the I1, not the I2 receptor type. Therefore it is of major interest to know the functional mechanism of central I2 receptors of which, in contrast to I2 receptors, little is known. To gain more insight we propose to determine the subcellular localization of these receptors and what their signalling pathway(s) can be. Subsequent purification and biochemical studies of the receptor molecule itself can inform us about its cellular effects and give an experimental basis for future determination of cDNA sequences and genetic studies. The results can provide new information to aid the design of newer generations of specific drugs for multiple diseases.