HISTOCHEMICAL LOCALIZATION OF CATECHOLAMINES IN THE URINARY BLADDER OF THE TOAD (BUFO MARINUS)

Fluorescent histochemical localization of monoamines in whole mounts of the bladder of the toad ( Bufo marinus) revealed bundles of fluorescent nerves containing predominantly adrenaline. These formed a wide meshed net work about arteries but not veins. A small proportion of muscle bundles was supplied by fine varicose fluorescent nerves. Loading with adrenaline or noradrenaline increased the intensity of the fluorescence in the nerves, but produced no appreciable increase in the number of muscle bundles supplied by fluorescent nerves. Large, brilliantly fluorescent cells containing a primary monoamine were located along nerve bundles. Chronic reserpine treatment abolished the fluorescence in nerves but not in these cells. Ganglion cells showed no specific fluorescence, nor did fluorescent terminals impinge on them, but many ganglion cells contained autofluorescent granules. The significance of the presence and localization of catecholamines in the toad bladder is discussed in relation to the pharmacology of the organ and to histochemical investigations of the innervation in other vertebrate bladders.