FIG. 1.

The appearance of Paneth cells in the ileal crypts 24 h after newborn rats received either intraperitoneal dithizone (75 mg/kg) in 25 mM lithium carbonate buffer or L₂CO₃ buffer alone. Photomicrographs are ileal sections stained with hematoxylin and eosin (magnification, ×1,000). The arrows identify individual Paneth cells. Paneth cells were examined for the content and the nature of their eosinophilic granules by using a Lickert score of 1 to 3, with 3 being best. (A) Crypt with two Paneth cells in a rat pup treated with i.p. dithizone; the Paneth cell was assigned a score of 2, while the Paneth cell on the right had a score of 1. (B) Paneth cell of a pup given i.p. L₂CO₃ buffer; this Paneth cell was given a score of 3. (C) The same Paneth cell as in panel B, except the incident light has been changed to show the autofluorescence of the cytoplasmic granules. Only epithelia with this autofluorescence were judged to be Paneth cells.