IDENTIFICATION OF PROGRAMMED CELL-DEATH IN NORMAL HUMAN SKIN TISSUES BY USING SPECIFIC LABELING OF FRAGMENTED DNA

Programmed cell death (PCD) in normal human skin tissues was studied b y using in situ specific labelling of fragmented DNA. This labelling m ethod clearly stained the nuclei of Henle's layer in the bulb of the a nagen hair follicle in serial sections, and the nuclei of the inner ro ot sheath cuticle cells and Huxley's layer cells showed positive stain ing in the upper part of the hair follicles. This staining pattern was consistent with the sequence of keratinization in the three layers. T he nuclei of differentiated cells located at the centre of the sebaceo us glands, and those of the granular keratinocyte layer, were also sta ined. These findings suggest that PCD might play a key role in the ter minal differentiation of the epidermis and epidermal appendages.