Rejuvenation of epididymal principal cells by prolactin under androgen deficiency.

Influence of prolactin on the ultrastructure of principal cells lining the epididymal epithelium was investigated in Wistar rats. Orchidectomy produced degenerative changes suggesting that structural integrity of principal cell is maintained by factors originating in the testis. The atrophic changes in the principal cell of ordhidectomised rats were significantly reversed when prolactin was administered to these animals. The number of cells that responded were found to increase with the dose of prolactin injected. On the otherhand, bromocryptine treatment did not appreciably change the ultrastructure of principal cells in orchidectomised rats. Results suggest that prolactin may have a rejuvenating epididymal principal cells in androgen deficient states.

Impact of prolactin on epididymal lipid profile in castrated rats.

Prolactin treatment to castrated rats led to accumulation of triacylglycerol and esterified cholesterol. There was no appreciable drift in epididymal cholesterol: phospholipid ratio between the prolactin treated and control animals. However, further analysis of phospholipids showed a build up of phosphatidyl inositol, phosphatidyl choline and phosphatidyl ethanolamine but a drop in the levels of phosphatidyl serine and sphingomyelin in prolactin treated castrated rats as compared to those castrated animals injected with vehicle alone. Changes in phospholipids reported above were prominently seen in the group of castrated rats that received 100 micrograms oPRL/100 g body weight but not in those animals which received either lower or higher doses of the hormone. Interestingly, bromocryptine treatment in castrated rats produced a general depletion in the levels of all lipid classes studied in the epididymis. It is suggested that this may be due to impaired synthesis and/or increased breakdown of lipids in this organ.