Tezuka T, Hirai R
Curr Probl Dermatol. 1980;10:255-67. doi: 10.1159/000396294.
Three-day-old Sprague-Dawley rats were injected intraperitoneally with 100 muCi of [35S]cystine. They were then sacrificed at 30 minutes, 2, 4, and 10 hours. The skins were epilated by the beeswax-resin procedure and the epidermis was separated by soaking in NH4Cl solution. Neither hair with hair follicles nor hair sheath was attached to the epidermal sheets after the epilation. Keratohyalin granules were solubilized after the freezing and thawing procedure. Living cell layers were separated from stratum corneum following further incubation in NH4Cl solution. Both the living cell layers and the stratum corneum were extracted with 8 M alkaline urea. Seventy-two to 92% of the total radioactivity incorporated into epidermal proteins was found in the urea-insoluble fraction of the stratum corneum. Only 2.4 to 6.4% of the total radioactivity was incorporated into the keratohyalin granular fraction. The specific radioactivity which was incorporated into the urea-insoluble fraction of the stratum corneum was still increasing 10 hours after injection, though the radioactivity in other fractions was decreasing at 10 hours following injection. The highest specific radioactivity of [35S]cystine was found in the urea-soluble fraction of the living cell layers, and was being rapidly turned over.
给3日龄的斯普拉格-道利大鼠腹腔注射100微居里的[35S]胱氨酸。然后在30分钟、2小时、4小时和10小时后将它们处死。通过蜂蜡-树脂法脱毛，将表皮浸泡在氯化铵溶液中进行分离。脱毛后，毛囊和毛鞘均未附着在表皮片上。冷冻解冻后角蛋白透明颗粒溶解。在氯化铵溶液中进一步孵育后，从角质层分离出生存细胞层。生存细胞层和角质层均用8M碱性尿素提取。角质层尿素不溶部分中发现了72%至92%掺入表皮蛋白的总放射性。仅2.4%至6.4%的总放射性掺入角蛋白透明颗粒部分。尽管注射后10小时其他部分的放射性在下降，但注射后10小时角质层尿素不溶部分掺入的比放射性仍在增加。[35S]胱氨酸的最高比放射性出现在生存细胞层的尿素可溶部分，且周转迅速。
