Graduate School of Agricultural Science, Tohoku University, Sendai 981-8555, Japan.
Toxicon. 2013 Sep;72:23-8. doi: 10.1016/j.toxicon.2013.06.002. Epub 2013 Jun 13.
Pufferfish saxitoxin and tetrodotoxin binding protein (PSTBP) was previously isolated from the plasma of the marine pufferfish, Takifugu pardalis. In this study, we investigated distribution pattern of PSTBP in intestine, liver, ovary, skin, and skeletal muscle of T. pardalis by immunohistochemical staining for the study of functions of this protein. In the skin, dermis around the tetrodotoxin secreting gland was positive, while this secreting gland itself was negative. In the ovary containing vitellogenic oocytes, ovarian wall and vitelline envelope were positive, while yolk and nucleus were negative. In the liver, hepatocytes with large fat droplets and capillaries were positive. In the intestine, the lamina propria mucosae were positive, while the mucosal epithelium was negative. In the skeletal muscle, only capillaries were positive. Furthermore, liver specific expression of PSTBP was confirmed by Northern blot analysis. Based on these results together with reported tetrodotoxin localization pattern in pufferfish, PSTBP was assumed to be a carrier protein to transfer tetrodotoxin among the tissues, especially liver, ovary, and skin.
河豚鱼岩沙海葵毒素和河豚毒素结合蛋白（PSTBP）先前从海洋河豚鱼（Takifugu pardalis）的血浆中分离出来。在这项研究中，我们通过免疫组织化学染色研究了 PSTBP 在 T. pardalis 肠、肝、卵巢、皮肤和骨骼肌中的分布模式，以研究该蛋白的功能。在皮肤中，河豚毒素分泌腺周围的真皮呈阳性，而分泌腺本身呈阴性。在含有卵黄生成卵母细胞的卵巢中，卵巢壁和卵黄包膜呈阳性，而卵黄和核呈阴性。在肝脏中，具有大脂肪滴和毛细血管的肝细胞呈阳性。在肠中，固有层黏膜呈阳性，而黏膜上皮呈阴性。在骨骼肌中，只有毛细血管呈阳性。此外，通过 Northern blot 分析证实了 PSTBP 在肝脏中的特异性表达。基于这些结果以及河豚鱼中报道的河豚毒素定位模式，假设 PSTBP 是一种载体蛋白，可在组织之间，特别是在肝脏、卵巢和皮肤中转移河豚毒素。
