사료의 단백질이 조피볼락 혈액중 Insulin-like growth factor-I (IGF-I) 및 IGF-binding protein-3에 미치는 영향

Effects of Dietary Proteins on Serum Insulin-like Growth Factor-I (IGF-I) and IGF-Binding Protein-3 in Korean Rockfish, Sebastes schlegeli

조피볼락을 실험어로 하여 사료 단백질의 함량과 단백질원을 달리하여 공급한 후 동물의 성장인자 중 하나인 Insulin-like growth factor-I (IGF-I)과 IGFBP-3의 혈중농도를 검토하였다. 사료 단백질의 함량이 $50\%\sim60\%$ 급여군에서 성장이 좋았고, 혈액중 IGF-I 농도도 높게 나타났다. 그리고 콘글루텐과 우모분 보다 질적으로 우수한 어분, 대두박분, 육분을 첨가한 사료로 사육한 조피볼락의 혈액중 IGF-I과 IGFBP-3가 높은 것으로 나타났으므로, 어류 단백질 대사수준을 파악하는 지표로 활용이 가능하였다.

Insulin-like growth factor-I (IGF-I) is a mitogenic peptide with a molecular mass of 7 kDa. It is produced mainly in the liver and has important functions in the regulation of development and somatic growth. Moreover, Serum IGF-I concentration is regulated by the quantity and the nutritional quality of dietary protein. To determine the IGF-I level in Korean rockfish, Sabastes schlegeli, were fed four experiment diets that contained different protein quantities, namely $30\%,\;40\%,\;50\%\;and\;60\%$ for 70 days. Weight gain of the fish increased depending dietary protein quantity, Also, IGF-I concentrations increased according to dietary protein quantity, Feeding experiments were conducted to examine the effects of dietary protein sources on the serum IGF-I level in Korean rockfish, Fish meal (CO), soybean meal (SM), corn-gluten meal (CGM), meat meal (MM) and feather meal (FM) were used as variable protein sources of the formulated diet. IGF-I concentrations of the CO and MM groups ($277.7\pm23.2,\;291.5\pm41.2\;ng/mL$) were higher than those of the CGM and FM groups ($208.9\pm21.3,\;217.2\pm38.2\;ng/mL$). And IGFBP-3 levels by western blot analysis increased in good protein diets such as in the CO and MM groups. In conclusion, IGF-I may be a sensitive indicator the protein metabolism in fish as well as mammalian.