Effect protein deficiency on lnsulin like growth factor-I and lnsulin like growth factor-II gene expression physiological reles of lnsulin like growth factors as a local factore in growing lambs-

1997 Fiscal Year Final Research Report Summary

• Project/Area Number: 08660343
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Applied animal science
• Research Institution: KYOTO UNIVERSITY
• Principal Investigator: MATSUI Tohru Kyoto University Graduate School of Agriculture, Associate Professor, 農学研究科, 助教授 (40181680)
• Co-Investigator(Kenkyū-buntansha): HIGUCHI Keiichi Kyoto University, Chest Diseases Research Institute, Lecturer, 胸部疾患研究所, 講師 (20173156)
• Project Period (FY): 1996 – 1997
• Keywords: Sheep / lnsulin like growth factor-I / lnsulin like growth factor-II / Protein deficiency / Cartilage / liver

Research Abstract

To study the mechanism of relationship between protein nutrition and bone growth, growing lambs were fed protein deficient diet or control diet and the gene expression of lnsulin like growth factor-I and lnsulin like growth factor-II were measured by RT-PCR in the growth cartilage. Additionally plasma concentrations of lnsulin like growth factor-I and lnsulin like growth factor-II were determined by dadio immunoassay. Male castrated lambs weighing approximately 20 kg were allotted to two groups in a double reversal design. These animals were fed control diet (crude protein content ; 17.5%) or protein deficient diet (crude protein content, 4.9%) . Energy contents in these diets satisified for its requirement. Protein deficiency suppressed body weight gain. Plasma insulin like growth factor-I concentration was lowered When lambs were fed the protein deficient diet. Compared to lnsulin like growth factor-I, plasma lnsulin like growth factor-II concentration was remarkably low in each group. And plasma lnsulin like growth factor-II was not affected by protein deficiency. Transcript of lnsulin like growth factor-I in the growth cartilage tended to be reduced by protein deficiency though this change was not significant. However, transcript of lnsulin like growth factor-II in the growth cartilage was not affected by protein deficiency. These results suggested that protein deficiency suppressed bone growth through reducing plasma lnsulin like growth factor-I concentration and locally produced lnsulin like growth factor-I in the growth cartilage. However, plasma lnsulin like growth factor-II and locally produced lnsulin like growth factor-II were not related to the retardation of bone growth in protein deficient sheep.