Development and androgen regulation of the secretory cell types of the Syrian hamster (Mesocricetus auratus) Harderian gland

The secretory cell types of the hamster Harderian glands were studied in both male and female Syrian hamsters. As previously demonstrated, female hamsters showed a single secretory cell type (type I), while male hamsters displayed two secretory cell types (type I and type II). Type-II cells were observed after the first month of age correlating with the increase in testosterone levels. The administration of testosterone to adult female hamsters resulted in a marked increase in the percentage of type-II cells without a significant increase in the number of mitotic figures. Very low levels of serum testosterone were able to maintain the percentage of type-II cells. Castration of male hamsters produced a decrease in the percentage of type-II cells. This drop correlated with the reduction in serum testosterone levels. The chronic administration of a luteinizing hormone-releasing hormone agonist to male Syrian hamsters induced a significant reduction in both serum luteinizing hormone and testosterone. However, the percentage of type-II cells was similar to that of control hamsters suggesting that very low levels of circulating testosterone are able to maintain the percentage of type-II cells. In a final experiment male Syrian hamsters were treated with the antiadrogen cyproterone acetate. No changes were observed in the percentage of type-II cells, whereas serum luteinizing hormone and testosterone levels were significantly modified. We concluded that (1) type-II cells differentiate from type-I cells; (2) gonadal androgens are the major factor controlling this differentiation; and (3) the disappearance of type-II cells after androgen deprivation occurs through holocrine and apocrine mechanisms. The possible implication of 5α-reductase in the regulation of secretory cell types in the Harderian glands of hamsters is discussed.