Characterization of the choroidal mast cell.

The experimental studies performed on nonpigmented rat choroids and the review of the important literature covered in this thesis seem to justify the following statements: 1. Mast cells are present in the choroid in significant numbers. 2. Mast cell numbers vary considerably from one individual to another and from one location in the choroid to another. 3. The major concentration of mast cells in the uvea is in the posterior choroid. 4. The mast cells of the choroid have a preferential location along arterial vessels. 5. Choroidal mast cell population density apparently decreases with senescence. 6. Mast cell products are present in sufficient quantity to exert substantial effects on physiologic, immunologic, and inflammatory responses in the choroid. 7. Choroidal mast cell products are released with appropriate stimulation and share some properties with the connective-tissue mast cell. 8. Choroidal mast cell demonstrate enough differences to suggest that a local differentiation may be present and may represent a locally controlled modulating effect for choroidal physiologic, immunologic, and inflammatory reactions.