Research on the identification of growth-stimulating peptides from the ovarian envelopes of salmon

鲑鱼是日本东北和北海道地区最重要的水产资源之一。腌制的鲑鱼子或IKRA的商业价值很高，但去除IKRA后的卵巢包膜没有太多实用价值。为了证实鲑鱼卵巢被膜中生长素的存在和功能，我们试图从鲑鱼的卵巢被膜中分离出一种与生长调节有关的多肽。至少纯化了5个多肽。这些多肽的相对分子质量在6.7-17.5 kDa之间，但没有测定它们的氨基酸序列。10.9 kDa多肽刺激虹鱼肝脏胰岛素样生长因子-I基因表达。这些结果表明，10.9 kDa的多肽可能参与了鲑鱼的生长调节。

Chum salmon is one of the most important aquatic resources in Tohoku and Hokkaido areas of Japan. The salted salmon roe or ikra is high in commercial value, but the ovarian envelopes after removing ikra don't have much utility value. To demonstrate the presence and functions of growth-stimulating peptide in the ovarian envelopes, we tried to identify a peptide involved in growth regulation from ovarian envelopes of salmon.The 80% acetone extracts of the ovarian envelopes was fractionated by gel filtration chromatography, and peptides were purified by HPLC. At least 5 peptides were purified. Molecular weight of these peptides was estimated from 6.7 to 17.5 kDa, but amino acid sequence of these peptides was not determined. A 10.9 kDa peptide stimulates hepatic Insulin-like growth factor-I mRNA expression of rainbow trout. These results suggest that the 10.9kDa peptide might be involved in growth regulation of salmon.