Identification of the AR and ER β in normal human platelets.

Lysates from human cell lines or normal human platelets were analyzed by immunoblotting with polyclonal antisera specific for ER β (panel A) and for the AR (panel B). Total lysates were made from the prostate carcinoma cell line LNCap (lane 1), HEL (lane 2), normal male platelets (lane 3), and normal female platelets (lane 4). For both panels A and B, the same molarity of peptide was used in lanes 5-8 as in lanes 9-12, and the filter shown in lanes 5-8 was stripped and reprobed and shown to contain ER β and AR, respectively (not shown). (A) In all lanes, 40 μg of protein lysates were loaded. Filters were probed with a 1.5 μg/mL of anti-ER β (Upstate Biotechnology, Inc) without (lanes 1-4) or with (lanes 5-12) the indicated competing peptide. (B) Twenty micrograms of LNCap and HEL cell lysates and 40 μg of platelet lysates were electrophoresed. Filters were probed with 0.15 μg/mL PG-21 (Upstate Biotechnology, Inc) without (lanes 1-4) or with (lanes 5-12) the indicated competing peptide, as described in “Materials and methods.”