IGF LR 3 may also be produced under the name long R3 IGF-1. It is more formally known as insulin-like growth factor 1 with long R3. This model represents a peptide variant of hormones, which act in a similar nature to insulin. This peptide was designed with a single chain structure that is made up of 83 main amino acids, which can take on additional amino acids as necessary. IGF LR3 is not glycosylates and the molecular weight of the peptide remains around 9200.

IGF LR3 has a single substitution that adds 13 amino acids from the standard IGF-1 structure. This addition allows this insulin variant to produce proteins that are more stable and effective within animal tissues.

This increase also extends the half-life of the product and makes it more stable, by limiting the ability to bind with other proteins. IGF-1 LR3 was created by GroPep Ltd for use in research on cultured cells, though many research facilities have moved on to using this peptide on live test subjects as well.

Systematic Infusion Stimulates Organ Proliferation and Growth

Studies investigating the gastrointestinal response to IGF-1 administration in suckling rats were performed, to better understand the potential for these peptides.

Neonatal rats were given administrations of IGF-1 LR1 or IGF1 Arg3 for 6.5 days either 6 or 12 days postpardum. Peptides were supplied to the rats, using mini osmotic pumps with increasing dosage for each test group.

IGF-1 infusions were found to increase plasma levels of natural IGF in both age test groups, but only increase weight gain for the 12 day old group. Both groups saw an increase in IGF binding, kidney and spleen weights. Gut length was increased but this was dose-dependent, in older rats.

Results indicate that IGF-1 based peptides are capable of selective stimulation of growth in gastrointestinal tissue of suckling rat test subjects.

Improving Remnant Function in the Small Intestine

Effects of a week-long infusion of IGF LR3 on the absorptive function and growth were noted in rats which had 70-80 percent of their jujuno ileum removed while compared to some responses.

IGF LF3 was noted to cause an attenuated malabsorption of nitrogen and fats in those with 70 percent of the jejuno ileum. Those with an 80 percent removal saw less-substantial effects, but reduction of malabsorption appeared to be administration dependent.

Gut weight in the rats increased by 21 percent which was at least partially attributed to peptide administration. Research suggests that IGF-1 based peptides can be used to improve gut absorptive function, by creating a slight increase in surface area.

Anabolic Effects

Administering IGF-1 for 14 days in female rats that were still developing via osmotic pumps was shown to cause an increase in weight gain and food conversion efficiency.

The effects of this application was dose dependent with larger doses of IGF LR3 showing some of the highest increases.

Organ and carcass composition measurements noted that IGF peptides maintained most body proportions that were present at the start of the experiment.

Variants of this peptide appear to bind with proteins less effectively.

Research has already confirmed that IGF-1 LR3 has stronger properties than the initial IGF. It can also produce higher muscle tissue density by increasing the reaction of hyperplasia in the cells. This peptide can release g-hormone responses while stimulating cellular functioning so that cells will become more sensitive to insulin. Modifications in this structure will also transport glucose and amino acids to cells, to increase the size of muscle tissue and mobilize fats.