Quantitative ultrastructural autoradiographic study of RNA transport in rat ventral prostate

The nucleocytoplasmic RNA transport in rat ventral prostate was studied by electron microscope autoradiography. Isolated prostate acini from normal, castrated, and DHT-treated animals were labeled in vitro with [3H]uridine for 5 min and chased for 0, 15, 30 min and 4 hr. The results show that DHT induces a significant nucleolar enlargement but intranuclear migration of rRNA is not apparently affected by androgens; migration of RNA through euchromatin is delayed by castration and stimulated by DHT; migration through the nuclear envelope is androgen-dependent. In addition prostate acini were maintained for 24 hr in suspension culture in order to study the in vitro effects of DHT. The result show that DHT stimulates uridine uptake and/or incorporation but induces no nucleolar enlargement; DHT has no clear effects on RNA migration kinetics; cytoplasmic transport of RNA in cells cultured in medium with or without DHT is severely impaired but is restored after supplementation of medium with insulin and dexamethasone.