Morphological Studies on the Autonomic Nervous System of Hypertensive Rats : IV. Fluorescence Microscopical Observation on the Superior Cervical Sympathetic Ganglia of Spontaneously Hyper tensive Rats

Distribution of cellular catecholamine in the sympathetic neurons of superior cervical ganglia of the rats was studied by fluorescence method of FALCK and HILLARP. A total of 10 male spontaneously hypertensive rats (OKAMOTO and Awoke) (consisting of 5 animals of 40 to 50 days of age and 5 rats of 4 to 5 months of age) and 10 male normotensive control rats of Wistar strain were subjected to examination. 2. The sympathetic neurons in the superior cervical ganglia of the normotensive rats showed specific formaldehyde-induced green or yellow-green fluorescence, which is due to the presence of noradrenaline. The cell populations with such specific fluorescence were heterogeneous in respect of fluorescence intensity. 3. The fundamental fluorescence microscopical feature in the ganglionic neurons of the spontaneously hypertensive rats did not differ from that of the controls. However, by statistical analysis of distribution of cell populations in respect to fluorescence intensity, the significant increase of frequency of intensely fluorescent nerve cells was proved in 4 of 5 spontaneously hypertensive rats of 40 to 50 days of age and 4 of 5 spontaneously hypertensive rats of 4 to 5 months of age. 4. From the above results, possible augmentation of sympathetic neural activity in the spontaneously hypertensive rats was assumed and discussed in relation to the significance of catecholamine in the sympathetic ganglionic neurons.