A study spanning two breeding seasons was carried out to examine the role of androgens in the control of the frontal and gular scent glands of the marsupial sugar glider Petaurus breviceps Waterhouse in a wild population. Animals were captured at monthly intervals and from these blood samples were taken and tissue biopsy samples were collected from the scent glands.
Several histological parameters underwent seasonal changes which were related to changes in the plasma concentration of free plus albumin bound (‘biologically active’) testosterone. The parameters which showed significant change did so during the July-September breeding season coinciding with the peak in biologically active testosterone concentration.
Castration caused a significant decrease in the nuclear diameters of gular and frontal apocrine and sebaceous gland cells, and a decrease in gular apocrine cell height. These decreases were reversed with androgen replacement therapy.
The nuclear diameters of apocrine tissue cells in both scent organs are positively correlated with the plasma level of biologically active testosterone. In the gular organ, but not in the frontal organ, the depth of apocrine tissue was significantly correlated with nuclear diameter. In castration and androgen replacement studies gular apocrine tissue responded more dramatically than did frontal apocrine tissue. This suggests that the gular organ is more sensitive to testosterone than is the frontal.