We have isolated, partially purified, and characterized the mast cells from human heart tissue. The histamine content of left and right ventricles and septum of hearts obtained from 25 patients undergoing heart transplantation was 5.4 ± 0.6, 5.3 ± 0.5, and 5.6 ± 0.5 μg/g of wet tissue, respectively. Ultrastructural study of cardiac mast cells revealed scroll, crystal, and mixed granules, homogeneously dense granules, and lipid bodies in the cytoplasm. A mild collagenase digestion was used to disperse the heart mast cells; the average yield was 3.2 ± 0.6% (range: 0.8 to 13.6%). The average histamine and tryptase content/heart mast cells was 3.3 ± 0.2 pg ( n = 25) and 24.2 ± 4.3 μg/106 cells (n = 11), respectively. Survival of cardiac mast cells after overnight culture was 71.9 ± 5.4% (n = 23). The purification of human heart mast cells can be brought from less than 0.1 to 12% by a combination of low-speed centrifugation over albumin (2%) solution and Percoll gradient. Viability as shown by trypan blue exclusion was greater than 90%. Heart mast cells released histamine in response to immunologic (anti-lgE, antiFcεRI, and C5a) and nonimmunologic stimuli (recombinant human stem cell factor, A23187, and compound 48/80) but did not respond to substance P, FMLP, 12-O-tetradecanoylphorboI-13-acetate, or acetylcholine. There was a linear correlation between the percentage of release caused by anti-IgE and anti-FcεRI, whereas there was no correlation between the release caused by C5a and anti-lgE-mediated stimuli. Cross-linking with anti-lgE of IgE on heart mast cells induced the release of tryptase (10.1 ± 2.1 μg/107 cells; n = 10) and the de novo synthesis of PGD2 (17.3 ±4.3 ng/106 cells; n = 10) and of leukotriene C4 (19.1 ± 4.5 ng/106 cells; n = 10). There was a linear correlation between the percentage of histamine secretion and tryptase release (r = 0.67; p <0.001) induced by cross-linking of FcεRI. Similarly, there was a significant correlation between percentage of histamine secretion and PGD2 (r = 0.63; p <0.001) and LTC4 (r = 0.64; p <0.001) release. Immunoelectron microscopy demonstrated the presence of chymase in cardiac mast cells. Mast cells isolated from human heart can be a useful model with which to study the role of these cells and their mediators in cardiac anaphylaxis and cardiovascular diseases.
|Number of pages||11|
|Journal||Journal of Immunology|
|Publication status||Published - 1995|
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