Calcitonin gene-related peptide-like immunoreactive cells in the secretory portions of rat sweat glands.

We found cells with calcitonin gene-related peptide-like immunoreactivity and with many cored vesicles in the secretory portions of sweat glands of rat foot pads. About 10% of sweat glands contained single immunoreactive cells. The immunoreactive cells were flask-shaped, with a narrow apex facing the glandular lumen and the bulk of the cell body in the basal half of the glandular wall. In the cytoplasm, there were many vesicles, 100-250 nm in diameter, with cores of various electron densities. These cytochemical and cytological characteristics suggest that the immunoreactive cells are homologous to gastrointestinal basal granulated cells.