A quantitative PCR measurement of messenger RNA expression of IGF-I, IGF-II and IGFBP-5 in human skeletal muscle

Insulin-like growth factor-I and -II (IGF-I and IGF-II) and their binding p roteins are important components in growth promotion and tissue maintenance . We determined the presence of IGF-I, -II, and binding protein 5 (IGFBP-5) gene expression in human skeletal muscle and that mRNA abundance is not al tered by nutrients and insulin. In the first protocol, (control) subjects w ere given water. In the second protocol, half of these subjects drank Polyc ose (carbohydrate) and the remaining subjects drank equal calories as a mix ed meal. Quadriceps muscle biopsies were taken at 10 h. A semi-quantitative polymerase chain reaction was designed to measure gene expression. IGF-I, IGF-II and IGFBP-5 mRNA are present in adult human skeletal muscle, but no significant changes between meal groups were observed for IGF-I, IGF-II or IGFBP-5 mRNA levels, indicating that the expression of these genes are not altered acutely by nutrients and insulin. (C) 1999 Harcourt Publishers Ltd.