(bā'sō-fĭl , -fīl‵)

[basic (dye) + -phile]

ABBR: BA

1. A cell or part of a cell that stains readily with basic dyes such as methylene blue.
2. A type of cell found in the anterior lobe of the pituitary gland . It usually produces corticotropin (ACTH), the hormone that stimulates the adrenal cortex to secrete cortisol.
3. One type of granulocytic white blood cell. Basophils make up less than 1% of all leukocytes but are essential to the innate immune response of inflammation because they release histamine and other chemicals that dilate blood vessels and make capillaries more permeable. SYN: basophilic leukocyte.

   SEE: blood for illus.