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, f emale hamsters showed a single secretory cell type (type I), while mal e hamsters displayed two secretory cell types (type I and type II). Ty pe-II cells were-observed after the first month of age correlating wit h the increase in testosterone levels. The administration of testoster one to adult female hamsters resulted in a marked increase in the perc entage of type-II cells without a significant increase in the number o f 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 corr elated with the reduction in serum testosterone levels. The chronic ad ministration of a luteinizing hormone-releasing hormone agonist to mal e Syrian hamsters induced a significant reduction in both serum lutein izing hormone and testosterone. However, the percentage of type-II cel ls was similar to that of control hamsters suggesting that very low le vels of circulating testosterone are able to maintain the percentage o f type-II cells. In a final experiment male Syrian hamsters were treat ed with the antiandrogen 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 tha t (1) type-II cells differentiate from type-I cells; (2) gonadal andro gens are the major factor controlling this differentiation; and (3) th e disappearance of type-II cells after androgen deprivation occurs thr ough holocrine and apocrine mechanisms. The possible implication of 5a lpha-reductase in the regulation of secretory cell types in the Harder ian glands of hamsters is discussed.