ELEMENTAL DISTRIBUTION IN GUINEA-PIG SKIN AS REVEALED BY X-RAY-MICROANALYSIS IN THE SCANNING-TRANSMISSION MICROSCOPE

[摘要] Skin from the back of guinea pigs was prepared for X-ray microanalysis by rapid freezing and cryosectioning; sufficient ultrastructural detail could be seen in the STEM[scanning transmission electron microscopy]-mode with staining. X-ray microanalysis by EM showed the S concentration to be highest in the stratum corneum and to decrease towards the stratum germinativum. The P concentration was very low in the stratum corneum, increased sharply in the stratum granulosum and remained at a high level throughout the rest of the epidermis. The distribution of K followed that of phosphorus. The Na level was low in the stratum corneum and increased sharply in the stratum granulosum. The K to Na ratio was highest in the stratum germinativum. The Ca and Mg levels in the epidermis were low. The results show the existence of marked concentration gradients for many elements in the skin. X-ray microanalysis is a method which can be applied to the study of shifts in the concentrations of physiologically important elements in the different strata of mammalian skin.