Kudo S, Yazawa S
Department of Anatomy, Gunma University School of Medicine, Maebashi, Japan.
Histochem J. 1997 Aug;29(8):607-16. doi: 10.1023/a:1026436311921.
The binding of antibiotics (gentamicin, oleandomycin and chloramphenicol) to vitelline and fertilization envelopes and their extracts was investigated by immunohistochemical and immunocytochemical techniques and immunoblot analysis using mature and artificially activated eggs of the fish Oncorhynchus masou. Binding of antibiotics was detected in the vitelline and fertilization envelope outermost layers, the fertilization envelope inner surface and cortical alveolus exudates, with differences in immunoreactive intensity and deposition. The fertilization envelope outermost layer had the capacity to bind much greater amounts of the antibiotics than the vitelline envelope outermost layer. The greater capacity was caused by the deposition of cortical alveolus exudates, which were known to be responsible for functional roles of protection against bacteria, fungi and noxious materials. Treatment of the vitelline and fertilization envelopes with neuraminidase markedly reduced the binding of gentamicin and chloramphenicol but slightly increased that of oleandomycin; binding of the latter to the vitelline and fertilization envelope outermost layers was considerably reduced after treatment with alpha-fucosidase. Treatment of the two envelopes with alpha-mannosidase, beta-galactosidase or beta-D-glucosaminidase did not cause any alteration in immunoreactive intensity or number of immunoreactive deposits. Immunoblot analysis of the vitelline or fertilization envelope extracts indicated that many of the antibiotic-binding substances were glycoproteins, and several major bands were bound by all three antibiotics. These results suggest that the vitelline or fertilization envelopes may have the ability to protect the egg itself, or the embryo, respectively, by trapping antibiotics, and the trapping may be related to the presence of carbohydrate moieties, such as sialyl or fucosyl residues.
利用虹鳟鱼成熟卵和人工激活卵，通过免疫组织化学、免疫细胞化学技术及免疫印迹分析，研究了抗生素（庆大霉素、竹桃霉素和氯霉素）与卵黄膜、受精膜及其提取物的结合情况。在卵黄膜和受精膜的最外层、受精膜内表面及皮质颗粒分泌物中检测到抗生素结合，免疫反应强度和沉积存在差异。受精膜最外层结合抗生素的量远大于卵黄膜最外层。这种更大的结合能力是由皮质颗粒分泌物的沉积引起的，已知皮质颗粒分泌物具有抵御细菌、真菌和有害物质的功能。用神经氨酸酶处理卵黄膜和受精膜可显著降低庆大霉素和氯霉素的结合，但略微增加竹桃霉素的结合；用α-岩藻糖苷酶处理后，竹桃霉素与卵黄膜和受精膜最外层的结合显著减少。用α-甘露糖苷酶、β-半乳糖苷酶或β-D-氨基葡萄糖苷酶处理这两种膜，免疫反应强度或免疫反应沉积物数量均无变化。卵黄膜或受精膜提取物的免疫印迹分析表明，许多抗生素结合物质是糖蛋白，所有三种抗生素都能结合几条主要条带。这些结果表明，卵黄膜或受精膜可能分别通过捕获抗生素来保护卵本身或胚胎，而这种捕获可能与碳水化合物部分（如唾液酸或岩藻糖基残基）的存在有关。
