title: Cellular proliferation and renewal in the various zones of the hamster epididymis after colchicine administration.
abstract: Cellular proliferation was examined in the various regions of the excurrent ducts of the reproductive system of the male golden hamster after colchicine administration. Each of the two zones of the ductuli efferentes displayed only infrequent mitotic figures. Similarly, the basal cell population of the epididymis as well as the epithelium of the vas deferens exhibited too few mitotic figures to allow meaningful evaluation of cellular proliferation. The following observations were reported. 1. The principal cells of the entire epididymis are characterized by a singular diurnal cycle of proliferative activity reaching its maximum about 3 P.M. and its nadir about 9 A.M. 2. A circadian rhythm of cell division is also found in the principal cells of each of the six zones of the epididymis, although the time of maximal activity may vary from zone to zone. 3. The most actively proliferating region of the excurrent duct system is zone 3 of the epididymis, whereas the least active region is the ductuli efferentes. 4. The renewal rates of the principal cells vary considerably at various points along the excurrent duct system, ranging from cells which renew themselves as many as 10 times to cells which fail to renew themselves at all during the normal life-span of the animal.
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002940:Circadian Rhythm; D003078:Colchicine / Q000494:pharmacology*; D006224:Cricetinae; D004285:Dogs; D004822:Epididymis / Q000033:anatomy & histology / Q000166:cytology / Q000187:drug effects*; D008297:Male; D008938:Mitosis / Q000187:drug effects; D013194:Staining and Labeling; D014649:Vas Deferens / Q000033:anatomy & histology / Q000166:cytology / Q000187:drug effects
chemical_list: D003078:Colchicine