The principal objective of the proposed research is continuation of the development of "phospholipid" renin inhibitors as pharmacologic tools to explore physiologic and pathophysiologic mechanisms of experimental hypertension and determination of the clinical potential of this class of agents as therapeutic and/or diagnostic antihypertensive drugs. The objectives are based on the finding that, in the acute and chronic two and chronic one kidney Goldblatt hypertensive rat, ecosatetraenyl (3-aminopropyl)phosphonate (URI-73A) has been demonstrated to lower blood pressure and the activity of renin, the enzyme component of the renin-angiotensin system. The chemial synthesis of quantities of URI-73A and structurally related analogs sufficient for dose formulation, pharmacological and biological studies, is proposed.