HISTOCHEMICAL AND ULTRASTRUCTURAL OBSERVATIONS ON THE IN VIVO UPTAKE OF EXOGENOUS NORADRENALINE AFTER RESERPINE TREATMENT

The fluorescence histochemical method of Falck et al., ('62) and an electron microscope were used for study on the uptake of exogenous noradrenaline (NA) by the adrenergic nerve terminal after reserpine treatment. The uptake of the NA was carried out during in situ application in the vas deferens of the rat pretreated with reserpine-iproniazid-pyrogallol by intraperitoneal administration. The NA was taken up in the adrenergic nerves, which showed a pronounced appearance of restituted NA fluorescence. Electron microscope studies revealed the reappearance of the small granular vesicles in restituted nerve terminals. Some terminals had almost the same appearance as compared with those seen in the normal tissue. These results indicate the occurrence of the uptake of exogenous NA into the small vesicles, in which the endogenous NA was depleted by reserpine pretreatment.