FURTHER STUDIES ON THE MECHANISM OF THE INCREASED OUTFLOW OF AQUEOUS HUMOR FROM THE EYES OF RABBITS TWENTY-FOUR HOURS AFTER CERVICAL SYMPATHETIC GANGLIONECTOMY

¹ Yale University School of Medicine, Section of Ophthalmology, Department of Surgery, New Haven, Connecticut

Evidence for the role of norepinephrine in producing the increase in outflow facility of aqueous humor from the eyes of rabbits 24 hr after cervical ganglionectomy has been sought and found. The phenomenon isprevented by virtual elimination of the norepinephrine stores in the iris and ciliary body by pretreatment with tyrothne analogs. The effect of reserpine upon the facility of aqueous outflow at certain time intervals after ganglionectomy is also related to the release of norepinephrune. The transient increase in outflow facility 1 hr after reserpine is produced by release or norepinephrine. After administration of reserpine for 1 week, increased aqueous outflow after ganglionectomy is probably caused by the persistence of pools of norepinephrine resistant to reserpine but susceptible to release after ganglionectomy. Prevention of increased outflow facility after ganglionectomy by iridectomy identified the iris as the source of norepinephrine for this effect. Failure of carotid ligation to block the ipsilateral increase in outflow facility after ganglionectomy demonstrated the independence of this phenomenon from variations in intraocular pressure and rates of formation of aqueous humor and indirectly supports the adrenergic nature of the increase in outflow facility.