MONOAMINE OXIDASE ACTIVITY OF CAT NICTITATING MEMBRANE AND SUPERIOR CERVICAL GANGLION UNDER VARIOUS EXPERIMENTAL CONDITIONS

Monoamine oxidase activity of the cat nictitating membrane and superior cervical ganglion was studied using a fluorimetric technique after chronic decentralization and denervation and pretreatment with reserpine and pheniprazine. Catecholamine content of the cat nictitating membrane and superior cervical ganglion was measured by using a fluorimetric technique after reserpine and pheniprazine pretreatments. Monoamine oxidase activity of the nictitating membrane was reduced in all procedures studied, while enzyme activity of the superior cervical ganglion was unchanged by sectioning of the preganglionic fiber (decentralization). Catecholamine content of the nictitating membrane was unchanged by pheniprazine treatment, while that of the superior cervical ganglion increased. Results are discussed in terms of the possible differences in the turnover rates of norepinephrine in the nictitating membrane and superior cervical ganglion. The effect of monoamine oxidase inhibition on reserpineinduced depletion of catecholamines in the cat nictitating membrane and in rat heart was also studied. The Catecholamine content of the cat nictitating membrane 18-24 hr after treatment with reserpine or with pheniprazine plus reserpine was reduced to the same extent. Similar results were obtained with the rat heart. The data support the concept that monoamine oxidase inhibition does not prevent the reserpine-induced release of catecholamines. © 1969.