Experimental studies are being undertaken of the mechanism of the intraocular pressure, aqueous humor dynamics, and vascular responses to adrenergic agonists, antagonists, and modulators. The studies involve predominantly conscious rabbits. Specific areas of immediate experimental concern include: (1) elucidation of the ocular response to beta1 and beta2 adrenergic receptor antagonists; (2) investigation of the influences of microtubular antagonists on intraocular pressure and on their ability to cause adrenergic supersensitivity in the eye; (3) studies of the total blood flow and segmental blood flow changes associated with the central and peripheral ocular responses to clonidine; (4) measurement of the influences of intraocular pressure on ocular blood flow using a microspher technique and its relation to the pulse pressure relationship of the eye. BIBLIOGRAPHIC REFERNCES: Krieglstein, G.K. and Langham, M.E. (1977). The biphaseic intraocular pressure and outflow facility responses of normal and glaucomatous eyes to epinephrine. Ophthalmic Research, in press. Langham, M.E. and Palewicz, K. (1977). The pupillary, the intraocular pressure, and the vasomotor responses to norepinephrine in rabbits. J. Physiology, in press.