Influence of some endocrine glands, hormones and blinding on the histology and porphyrins of the Harderian glands of golden hamsters.

Harderian glands of female or castrated male hamsters contained scattered luminal pigment deposits and a single cell type. Two cell types were found in the glands from intact males. Glands from both male and female animals showed abundant cytoplasmic lipids. Pigment formation appeared to be endogenous and in some cases occurred by extrusion of cells from alveolar walls and their subsequent transformation. Holocrine secretion was demonstrable. Porphyrin concentrations in the glands from females were increased three weeks after bilateral blinding and decreased following hypophysectomy, ablation of one Harderian gland, unilateral blinding, treatment with thiourea or exposure to an environmental temperature of 8°C. Ovariectomy or ovariectomy plus treatment with 17-α-estradiol for three weeks had no effect on the Harderian glands nor did pinealectomy. Porphyrin concentrations in the glands from male hamsters were extremely low. Castration increased these concentrations over 100-fold and modified the morphology toward that of the female while testosterone proprionate treatment prevented these changes. Administration of H3-thymidine and subsequent radioautography revealed a peak in mitotic activity between 9:30 PM and 12:30 AM at the end of the light period or the beginning of the dark period. Longterm blinded or blinded, castrated males had Harderian glands which were microscopically “lacelike” due to intense steatogenesis.