TY - JOUR T1 - ADRENERGIC MECHANISMS AND THE OUTFLOW OF AQUEOUS HUMOR FROM THE RABBIT EYE JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 60 LP - 65 VL - 144 IS - 1 AU - Kenneth E. Eakins AU - Helena M. T. Eakins Y1 - 1964/04/01 UR - http://jpet.aspetjournals.org/content/144/1/60.abstract N2 - The effect of denervation and decentralization on the norepinephrine and epinephrine content of rabbit ocular tissues has been studied. In normal tissues, highest concentrations of catecholamines were found in the iris and ciliary body, the predominant amine being norepinephrine. A significant decrease in the catecholamine content of rabbit ocular tissues was observed 24 hours after denervation. Three days after denervation the content was essentially zero. No recovery was observed up to 21 days. In contrast, decentralization was not found to deplete the norepinephrine content of rabbit ocular tissues 7 days after the operation. These results have been discussed in the light of present knowledge concerning the effect of denervation and decentralization on the aqueous humor dynamics of the rabbit eye. They support the view that the decrease in resistance to the outflow of aqueous humor observed 24 hours after denervation of the rabbit eye is due to the release of norepinephrine from the iris and ciliary body into the aqueous humor. Prolonged stimulation of the preganglionic cervical sympathetic nerve was not found to increase the norepinephrine content of aqueous humor. Such an increase did occur when the rabbits were pretreated with cocaine, but not with pyrogallol or iproniazid. These results suggest that uptake of norepinephrine into tissue stores plays a major role in the inactivation of norepinephrine in the rabbit eye. In addition, these results indicate that cocaine antagonizes the uptake of endogenous norepinephrine into tissue stores. The Williams & Wilkins Company ER -