The ultrastructure of epithelioid cells in the avian (Gallus domesticus) carotid body.

10 clinically healthy white leghorn males were utilised for this investigation. Apart from toluidine blue-pyronin-stained Araldite sections, uranyl acetate and lead monoxide staining revealed three types of epithelioid cells. Nuclear and cytoplasmic contents, especially three types of granules, conveniently designated as q, r and p granules, are described in detail and tabulated. Technical difficulties in obtaining carotid body tissue as well as clear-stained sections for ultastructural studies are mentioned.