The purpose of this study is to determine whether there is a modulating effect of the glucocorticoids and the mineralocorticoids in the control of ocular pressure. We will give corticosterone and aldosterone topically to rabbit eyes and systemically to rabbits and will study the effects on activity of sodiumpotassium ATPase, bicarbonate ATPase, and carbonic anhydrase in the irisciliary body. Dosereponse curves will be over pharmacologic and physiologic ranges. We will monitor ocular pressure to determine the effect of these corticoids on ocular pressure and determine aqueous humor flow by fluorophotometry. The effect of changes in the endogenous level of aldosterone on irisciliary body enzymes will be determined using the lowsodium diet model and the lack of response to acetazolamide on ocular pressure in a such a model. The parameters of the model will be determined in relation to sodium content of the diet, duration of the diet, and dose of actazolamide. The activity of sodiumpotassium ATPase, bicarbonate ATPase, and carbonic anthydrase will be measured in the irisciliary body of such rabbits in response to the diet and acetazolamide in relation to changes of levels of endogenous aldosterone.
