LIPID-COMPOSITION IN EPITHELIUM AND STROMA OF HUMAN BENIGN PROSTATIC HYPERPLASIA

The lipid composition and concentration in human benign prostatic hype rplasia (BPH) were investigated. The reason was to shed some light ont o the lipid environment of cellular membranes, in which the epithelial and stromal 5 alpha-reductase of the human prostate have apparently t o be embedded in order to gain an active state. The phospholipids were found to be the major portion (67% +/- 1.1) of total lipids in whole BPH homogenate, followed by cholesterol (29% +/- 1.1) and glyceride gl ycerols (4% +/- 0.9). In BPH epithelium, the lipid concentration relat ed to wet weight and to protein was two to three-fold higher than in s troma. Assigning the lipid concentration on a per-cell basis (i.e., re lated to DNA), a significantly lower lipid concentration was found in the epithelium as compared to the stroma. In the stroma, a significant ly higher phospholipid and lower cholesterol portion were found than i n the epithelium. Moreover, sphingomyelin was found to comprise a high er portion in stromal than in epithelial phospholipids, whereas the pe rcentage of phosphatidylserine was higher in the epithelial phospholip ids. We discuss whether the significant differences in lipid concentra tion and composition between the epithelium and stroma of human BPH co uld have an impact on the activity of the membrane-bound 5 alpha-reduc tase, or whether such differences in the lipid environment are due to a different hormonal milieu in the epithelium and stroma of BPH. (C) 1 997 Wiley-Liss, Inc.