Effect of puromycin on the ultrastructure of keratohyalin granules

Abstract

Keratohyalin granules (KHG) from control and puromycintreated hamster cheek pouch epithelium were studied by electron microscopy. The animals were killed 1–4 hours after injection with 75–100 microgram puromycin per gram body weight; controls were injected with saline. The KHG from control animals were round or oval and consisted of a finely granular background matrix containing many small, round, homogeneous electron‐dense deposits. The KHG from puromycin‐treated animals showed marked variation in morphology and size. They consisted of a coarse granular or speckled matrix and round, club‐shaped or comma‐shaped electrondense deposits. Since puromycin is known to inhibit protein synthesis, alterations in KHG structure support previous reports suggesting the protein nature of KHG.