Apoptosis and cell proliferation in the seminal vesicles and coagulating glands of male Syrian hamsters exposed to diethylstilboestrol (DES)

Regression of the accessory sex glands was induced in male Syrian hamsters by chronic exposure to diethylstilboestrol (DES), an agonist of 17 beta-oes tradiol. Experimental groups (n = 4-5) were killed at increasing time inter vals up to 6 months after initiation of treatment. Organ atrophy was evalua ted by morphological examination. Apoptosis in the seminal vesicles and coa gulating glands was visualized by in situ analysis of DNA fragmentation. Ce ll proliferation was monitored by immunostaining nuclei of S-phase cells af ter pulse labelling with BrdU. The volume of the seminal vesicles decreased drastically after 2 weeks of DES administration due to a marked reduction of secretions in the lumen of the glands. Cell proliferation in the seminal vesicles was stimulated by chronic administration of DES. Mitotic activity mostly increased during the first month of treatment, leading to epithelia l hyperplasia associated with progressive hyperplasia of the fibromuscular stroma. Evidence of epithelial dysplasia and metaplasia, often associated w ith an infiltration of polymorphonuclear leukocytes, was observed in animal s exposed to DES for 4 months or more. Regression of the seminal vesicles w as also associated with apoptosis in the gland epithelium. Apoptosis appear ed 3 days after starting DES administration and culminated at I month. Ther eafter the number of apoptotic cells decreased progressively, but apoptosis remained present until the end of treatment. In contrast, coagulating glan ds were less sensitive to DES. No major morphological changes were observed in these glands except for a moderate reduction of protein secretion. The levels of the apoptotic and proliferating cells indices were very low in th e coagulating glands during DES treatment. In conclusion, these data point to different sensitivities of the accessory sex glands to DES exposure beca use DES induces extensive alterations of the normal morphology of the semin al vesicles, but shows only a moderate impact on the coagulating glands.