Fig. 6.

Mast cells isolated from human lung express renin. (A) Toluidine-blue stained mast cells isolated from human lung tissue. (Scale bar, 10 μm.) (B) Total RNA was extracted from isolated human lung mast cells and reverse transcribed. cDNA was amplified by PCR using specific primers for human renin gene (exons 4–7). A 100-bp DNA ladder (m) was run on the gel. (C) Mast cells isolated from human lung stained positive for renin protein with the monoclonal anti-renin Ab (1:200). (Scale bar, 10 μm.) (D) Measurement of renin activity [ANG I formed (in picograms per milliliter per hour)] in the lysate from isolated human lung mast cells (±SEM; n = 3).