MACROMOLECULAR SYNTHESIS AND SECRETION IN MOUSE ALIMENTARY TRACT LIGHT AND ELECTRON MICROSCOPE AUTORADIOGRAPHIC STUDIES .2. INCORPORATION AND TURNOVER OF TRITIATED GLYCINE IN ESOPHAGEAL AND FORESTOMACH EPITHELIA

[摘要] Tne localization and turnover of the amino-acid glycine in mouse esophageal and forestomach keratinizing epithelia was investigated by means of light and electron microscope autoradiography. Grain counting procedures showed a higher localization of tritium label in the granular layer cells than in the rest of the epithelium. Within 24 hr. the highest percentage labelling occurred in the lower layers of the cornifled zone, indicating cell migration. Detailed analysis of developed photographic grain distribution over granular layer cells showed high percentage activities to be present in the peripheral cytoplasmic zones of these cells. Grains were also seen over keratohyalln granules and the nucleus. The possible connection between these sites of protein synthetic activity and the formation of the Interfibrillar matrix of keratin was discussed. Grains were observed in the upper cell layers of the cornified zone, especially in the 24 hr. preparations. The possible connection with the cementing substances lining the intercellular space was discussed.