Long arginine 3-IGF-1, abbreviated as IGF-1 LR3 or LR3-IGF-1, is a synthetic protein and lengthened analogue of human insulin-like growth factor 1 (IGF-1).[1][2] It differs from native IGF-1 in that it possesses an arginine instead of a glutamic acid at the third position in its amino acid sequence (arginine 3), and also has an additional 13 amino acids at its N-terminus (MFPAMPLLSLFVN) (long), for a total of 83 amino acids (relative to the 70 of IGF-1).[2] The consequences of these modifications are that IGF-1 LR3 retains the pharmacological activity of IGF-1 as an agonist of the IGF-1 receptor, has very low affinity for the insulin-like growth factor-binding proteins (IGFBPs), and has improved metabolic stability.[1][2] As a result, it is approximately three times more potent than IGF-1,[3] and possesses a significantly longer half-life of about 2030 hours (relative to IGF-1s half-life of about 1215 hours).[4] IGF-1 LR3 Peptide is under active investigation in a number of cell culture and animal models
Lancet 359:20532058 Belch J, Hiatt WR, Baumgartner I, Driver IV, Nikol S, Norgren L, Van Belle E, Committees T, Investigators (2011) Effect of fibroblast growth factor NV1FGF on amputation and death: a randomised placebo-controlled trial of gene therapy in critical limb ischaemia
Researchers study DSIP to investigate its potential roles in sleep modulation, stress response, pain control, and hormone secretion (LH, GH, ACTH)
The biology is doing what the theory predicts
Comment: Several commenters expressed concern that the heart failure EBCM does not capture the clinical complexity of the patients with heart failure, which can impact episode costs
