Attenuated glucose stimulated insulin secretion during an acute IGF 1 LR3 infusion into fetal sheep does not persist in isolated islets Journal of Developmental Origins of Health and Disease Cambridge Core Frontiers Sheep recombinant IGF 1 promotes organ specific growth in fetal sheep What is IGF 1 LR3?, Insulin Like Growth Factor 1 Long R3 (IGF 1 LR3) is a modified version of IGF 1 with a longer half life, making it significantly more potent and effective for muscle growth, Insulin Like Growth Factor 1 (IGF 1) and Its Monitoring in Medical Diagnostic and in Sports Insulin Like Growth Factor 1 (IGF 1) Physiopedia Mechanisms of IGF 1 Mediated Regulation of Skeletal Muscle Hypertrophy and Atrophy