Duration of the cycle of the seminiferous epithelium, estimated by the 5-bromodeoxyuridine technique, in laboratory and feral rats

The stability of the duration of the cycle of the seminiferous epithelium was determined by investigating incorporation of 5-bromodeoxyuridine into S-phase germ cells of normal and hemicastrated standard laboratory rats (Sprague-Dawley) and feral Brown/Norway rats (Rattus norvegicus). Feral rats were trapped on farms in the surroundings of Munster. The duration of the cycle of the seminiferous epithelium, determined at intervals of 12 days (3 hversus 12 days 3 h after 5-bromodeoxyuridine injection), was remarkably constant and similar in intact laboratory rats (12.49±0.05 days, n=13, mean±SEM) and feral rats (12.44±0.06 days, n=8)