Elaboration of Bicarbonate Ion in Intraocular Fluids: V. Contribution of the Lens to the Chemistry of Aqueous Humors of the Rabbit Eye

During the past two decades experimental and clinical investigations of the dynamics of aqueous humor formation have been largely influenced by the theories proposed by Friedenwald¹ and Kinsey.² Thus, the active transport of the bicarbonate ion across the ciliary epithelium into the posterior chamber is regarded as the primary and fundamental step in the secretion of aqueous humor of the rabbit eye. That the bicarbonate ion is actively transported into the posterior chamber is, however, based essentially upon the findings of Kinsey³ that the bicarbonate ion concentration in the aqueous humor is in considerable excess of that in the blood plasma. Similarly, the aqueous humors of other animals, such as guinea pig, dog, cat, and rat,⁴ have been shown to have excesses of bicarbonate in comparison with blood plasma. The existence of this concentration gradient together with the probability that the ciliary body is largely responsible