Photoperiodic influence on the innervation of the ductus epididymidis and ductus deferens of the Djungarian hamster, Phodopus sungorus: electron-microscopic and biochemical results.

The influence of long (light:dark 16:8) and short (light:dark 8:16) photoperiods on the autonomic innervation of the ductus epididymidis and the ductus deferens of Phodopus sungorus was studied using electron microscopy with morphometric analyses, and biochemical methods. At short photoperiods, only the large smooth muscle cells in the ductus deferens became atrophic, the number of mainly adrenergic varicosities in the smooth muscle layer decreased, and the mean distance between varicosity and smooth muscle cells increased. The content of noradrenaline was determined by high-performance liquid chromatography with electrochemical detection. For the ductus deferens, the noradrenaline content was reduced at LD 8:16 to less than 10% of the initial value. Short photoperiods are proposed to influence only the adrenergic innervation of the large smooth muscle cells of the ductus deferens. These cells are believed to exert a trophic influence on their nerves.