ADRENERGE INNERVATION IN TESTIS AND EPIDIDYMIS OF SWAN (CYGNUS OLOR)

The testis and epididymis of the swan were investigated by means of Falck's and Hillarp's method for fluorescence microscopical detection of catechol- and tryptamines. In the testis a dense plexus of green fluorescent nerve fibres was found to course between the tubuli seminiferi and to surround clusters of Leydig-cells. Electronmicroscopically numerous bare axons containing dense core vesicles were observed between individual Leydig-cells. These results favour the assumption that in contrast to what has been found in most mammals the testicular interstitial cell system of the swan is supplied by sympathetic nerve fibres. The adrenergic innervation of the excretory ducts was also found to behave different from that in mammals: The innervation is most dense in the proximal portions of the ductuli efferentes. From the results of microspectrofluorimetric measurements it is concluded that the transmitter is most likely noradrenaline. Fluorimetric determinations reveal the presence of high amounts of noradrenaline (5,16-5,50 μg/g). © 1968 Springer-Verlag.