Quantification and identification of particle movement in epidermis after thermal injury

Skin samples from a rabbit hind limb were taken from controls and at 5 min, 2 and 6 hr after a mild thermal injury (60 degrees C for 1 min). Large aggregates of intercellular particles, usually ribosomal in appearance, were seen in 6 hr samples and were accompanied by some peripheral aggregates of particles and by granule-coated vesicles. These structures were present in earlier samples to a lesser extent and were absent from control material. Quantitative assessment showed that intercellular particles apparently increased up to 6 hr whereas peripheral aggregation was maximum at 2 hr. Histochemical analysis confirmed that the particles contained ribonucleoprotein. Other larger particles were seen occasionally and contained carbohydrate. Lymph draining the site showed cellular changes, little change in enzyme activities, and no aggregates of particles.