Eur J Anat, 1 (2): 67-75 (1997)

Is there any relationship between cellular proliferation and the phenotypic changes that take place in the hamster harderian gland after orchidectomy?

A. Fernández-Suárez, J.M. López, s. Carbajo*, M. Fernández-Fuente, J. Álvarez-Piñera and E. Carbajo-Pérez

Oepartment of Morphology and Gell Biology, Faculty of Medicine, University of Oviedo, Oviedo. Spain. "Deperment of Human Anatomy and Histology, Faculty of Medicine, Universidad de Salamanca, Salamanca, Spain.

ABSTRACT To gain insight into the mechanisms underlying the phenotypical changes that take place in the Harderian gland of male Syrian hamsters after cas­tration, developing and adult hamsters were orchi­dectomized and the proliferative activity of the secretory cells was analyzed at different times after surgery. In castrated adults the percentage of type II cells decreased to reach very low levels that were maintained from the 20th day after cas­ tration. A parallel increase of type 1 cells was found. No modification of the overall cell density of the gland was found except for an ephemeral increase on the tenth day after castration. In adults the overall labelling index and the specific label­ ling index of type 11 cells run in parallel and fell20 days after castration. On the contrary, castra­tion did not modify the specific labelling index of type I cells. Castration on the 28th postnatal day followed a similar trend to that described in adults but castration on the 15th postnatal day resulted in an absolute absence of type I cells at the end of the study. These results show that the lack of androgens during the 3rd and 4th week of post­ natal day profoundly disrupts the process of diffe­ rentiation of type 11 cells that takes place during this period in the Harderian gland of males. After this critical period of differentiation a small re m­ nant of these cells can be found even forty days after removal of androgenic stimuli. The analysis of the proliferative activity strongly suggest that proliferation of type I cells does not play an important role in the redistribution of cell typesafter castration and that transformation of type 11 cells into type 1 cells, rather than a massive elimination of type 11cells from the gland, is the major event sustaining this phenotypical change.

Keywords: Harderian gland, orchidectomy, development, cellular proliferation, hamster.