McDouche
Registered
Hey guys,
Below is some IGF-1 LR3 info I have come across from all over the net to prepare for to use it this summer. I thought I would share some of my consolidated (and non-original) posts from all over the net. Just to be clear, I am not claiming ownership for any of this information.
Uses
Potential benefits of IGF-1 LR3
· Increased muscle growth
· Decreased body fat
· Increased nutrient shuttling capacity
· Increased muscle pumps
· Increased muscle fullness
· The ability to cause muscle cell hyperplasia
· Regeneration of nerve tissue
Reconstitution
Reconstitution is simply the addition of the 0.6% AA to your lyophilized IGF-1.
Assumption: 1mg/mL IGF-1/AA (1mg IGF-1 will be combined with 1mL AA; 1mg IGF-1 is the same as 1,000mcg). 0.6%AA can easily be found online or can be created using Vinegar (google it).
When reconstituted with AA, IGF-1LR3 is stable for about
1. Swab the top of your IGF-1 vial with a sterile alcohol prep pad
2. Swab the top of your 0.6% AA vial with a sterile alcohol prep pad
3. Using either multiple insulin syringe volumes (example: 2 x 0.5cc) or a single large syringe, obtain 1.0mL of 0.6% AA.
4. In the IGF-1 vial, insert a sterile ~20 ga. needle to act as a vent
5. Inject the 1.0mL of AA very slowly and dribble it down the side of the vial.
a. Be very careful with this peptide as it is very delicate!
6. Remove the needle & syringe and discard
7. Gently swirl the vial or roll between your hands.
a. Again, be very gentle here
8. You now have 1mg/mL of IGF-1
a. This is the same as: 1,000mcg/mL
Notes:
1. If you added 2mL of AA, it would be a 0.5mg/mL
Back-Loading With Bacteriostatic Water (BW)
Back-loading is a process in which you dilute the IGF-1/AA solution that is in your syringe. The point is to dilute the acidity to a point that it will no longer cause tissue necrosis (death/damage) or pain upon injection. It is recommended to dilute no less than 4:1 (4 parts BW to 1 part IGF-1/AA).
Example: If you are injecting 40mcg bilat, IM, you will have two syringes each with 20mcg IGF-1. Assume you want to draw 2 IU IGF-1. You will draw 2 IUs of the IGF-1/AA solution, then draw 2x4 = 8 IUs of BW (four times the amount of IGF-1/AA solution). The total number of IUs in each syringe will be 2 + 8 = 10 IUs. It will not hurt you if you decide to back-load with more BW. It is a personal preference. Injection Directions
1. Wash your hands thoroughly
2. Optional: put on exam gloves and rub with IPA until dry
3. Using an alcohol swab, clean the tops of both the IGF-1 vial and the BW vial.
4. Using a fresh alcohol swab, thoroughly clean the injection sites (let dry)
5. Fill each syringe with the appropriate amount of IGF-1/AA solution
a. Do NOT touch the needles to anything but sterile surfaces!
b. It is recommended that you clean/sanitize the area/surfaces you’re working in, in case you mindlessly touch a needle to a table (or other area).
6. Back-loading: Draw up the necessary amount of BW into each syringe.
a. Tilt the needle up and down so the bubble(s) rise and fall, which mixes the solution slightly
7. With the needle pointing up, flick the syringe body to get the bubbles to rise to the needle
8. Slowly expel the air; be careful to not quirt liquid out as this wastes IGF-1
a. It takes >3mL of air to cause harm; small volumes of accidentally injected air will most likely be absorbed by muscle tissue
9. Insert syringe and aspirate by slightly pulling up on the plunger to see if you have hit a vessel. If you see blood, remove needle, and try again (no need to change syringes). If you do NOT see blood, proceed to inject.
10. Perform “7.” thru “9” above on other side.
11. Discard sharps in appropriate container
Stability
Stability at room temp after reconstituting with AA is probably a few years
Reconstituting in BAC it has a stability of only a few hours at room temp and a month refrigerated.
In powder form, it should be good for a long time.
Storage Condition: -20 C (-4 F)
Biological Potency No Change up to 2 years
Immunological Activity No Change up to 2 years
Mobility of Protein No Change up to 2 years
Elution Profile by reversed phased HPLC No Change up to 2 years
Storage Condition: +4 C (39.2 F)
Biological Potency No Change up to 2 years
Immunological Activity No Change up to 2 years
Mobility of Protein No Change up to 2 years
Elution Profile by reversed phased HPLC No Change up to 2 years
Storage Condition: +22 C (71.6 F)
Biological Potency No Change up to 2 years
Immunological Activity No Change up to 2 years
Mobility of Protein No Change up to 2 years
Elution Profile by reversed phased HPLC No Change up to 2 years
Storage Condition: +37 C (98.6 F)
Biological Potency No Change up to 1 year
Immunological Activity No Change up to 1 year
Mobility of Protein No Change up to 1 year
Elution Profile by reversed phased HPLC No Change up to 1 year
Dosing
Dose per injection: 40-80mcg
Injections per vial: 20 @ 50mcg dosages
Amount to Inject: If you have used 1ml of water for mixing then a 50mcg dosage = 0.05ml (or 5 units on Insulin Syringe). If you have used 2ml of water for mixing then 50mcg = 0.10ml (or 10 units) and if you have used 3ml of water for mixing, then 50mcg = 0.15ml (or 15 units).
Can be injected pre or post workout.
Many choose to pin bilaterally hoping for a localized effect (for example 25mcg right and left biceps) however, with the long active life of IGF-1 LR3, it is most likely the affect will be systemic.
Research
The insulin-like growth factors (IGFs) are peptides with sequence similarities to insulin. IGF-1 is mainly secreted by the liver via stimulation of GH (growth hormone); this is the primary mechanism of what is known as the IGF/GH axis.. IGF-1 plays a role in both normal, healthy bodily processes as well as other disease states. Because it plays roles in both cell proliferation and inhibition of apoptosis, IGF-1 is important for both normal and abnormal cell growth. Creaney and Hamilton write the following on the topic of IGF-1 and its role in the body, as well as its potential in diagnosing certain disorders:
IGF-1 is a 7.5 kDa polypeptide that is structurally similar to insulin.50 It induces proliferation, differentiation and hypertrophy of multiple cell lines, in particular skeletal muscle, and has an additional role of facilitating glucose entry into skeletal muscle cells... IGF-1 is secreted as the result of a hypothalamic-pituitary liver axis. The hypothalamus secretes growth hormone-releasing hormone (GHRH), which stimulates the pituitary to release growth hormone, which in turn stimulates the liver to release IGF-1. Like most endocrine systems, the system is controlled by negative feedback, thus in normal individuals, exogenous administration of IGF-1 will lead to suppression of the axis. Whereas growth hormone secretion is pulsatile, with greatly varying levels in a 24-hour period, serum IGF-1 levels are relatively stable within a 24-hour period; hence, measurement of the serum IGF-1 level is now the favoured test for acromegaly or growth hormone deficiency.[3]
High IGF-1 levels are correlated with higher levels of lean body mass. Neuroprotective, myelinatory, synaptogenic, and anti-catabolic effects of IGF-1 are well-documented in human and animal study subjects. Serum IGF-1 levels correlate positively to higher IQ in children. [12]
IGF-1 is also manufactured in skeletal muscle. A form of IGF-1 known as IGF-1 LR3, when applied from an exogenous source, has been shown to circulate longer and bind to more targets in the body than regular IGF-1 as the body manufactures it; further, Dunshea finds that "long arginine (LR3) IGF-I, has been shown to be more potent than IGF-I in the rat."[11]
Exogenous IGF-1 has been shown to "increase muscle mass and promote muscle cell proliferation, differentiation, and survival." [10] For this reason, IGF-1 is of great interest to current researchers... IGF-1 affects nearly every cell in the human body.
IGF-1 is a candidate for being used as a neurotrophic agent in what is known as gene therapy to effect new nerve growth in victims of severe trauma who experience nerve damage and related symptoms. [1] Even though microsurgical techniques have improved vastly in the past decade, IGF-1 offers great potential as a concurrent treatment in addition to current microsurgical techniques due to its ability to not only generate new nerve growth (neurotrophy) but also to promote proliferation of muscle cells in damaged areas. IGF-1 also acts as a survival factor for spinal cord motor neurons, increasing its potential further. [1]
Rabinovsky writes that "nerve sprouting within skeletal muscles is an essential restorative process in response to an injury or a pathological condition. IGF-1 increases intramuscular nerve sprouting 10-fold when administered subcutaneously to normal adult rats" and also that "IGF-1 is also a potent myogenic factor, promoting myoblast proliferation, myogenic differentiation, and myotube hypertrophy." [1] Rabinovsky's own studies show that "when the sciatic nerve is injured,increased local expression of IGF-1 in muscle hastens motor nerve and muscle repair." [1]
Upton et al, "assessed the [IGF-1] complexes as a topical agent in wound healing studies conducted in 3-dimensional in vitro human skin equivalent models, as well as in the treatment of deep partial thickness wounds in two different porcine models. This has revealed that the VN:IGF-I:IGFBP complexes hold promise as a wound healing therapy." [2] Of interest to other researchers is that significant positive results "were obtained with nanogram doses of growth factors." [2] IGF-1 plays an integral role in the body's own healing process and binds more strongly to damaged tissue. Other researchers have found that without a hypertrophy stimulus, the muscle-building effects of IGF-1 are unrealized; this is likely for the same reason that Upton et al found injured tissue strongly attracts IGF-1 binding.In fact, IGF-1 is not even released from skeletal tissue in the absence of exercise. [3]
IGF-1 is well-studied and there is a research consensus on its effectiveness for "healing of tendon and muscle injuries. According to Creaney and Hamilton, "IGF-1 has been used in isolation by a number of investigators. Animal studies have suggested a role for IGF-1 in both the acceleration and enhancement of healing of tendon and muscle injuries" [3]
Maetsu et al, in a study on IGF-1 levels in bodybuilders in competition condition, found "data [to] indicate that severe energy restriction to extremely low body energy reserves decreases significantly the concentrations of 3 anabolic pathways despite high protein intake." Maetsu concludes that "Monitoring of insulin and IGF-1 concentration is suggested to prevent losses in muscle mass in energy-restricted conditions" and that "other nutritional strategies might be needed to prevent possible catabolic effect during preparation of bodybuilders to competition." [6]
Yoshida, et al, demonstrate the converse side of the negative correlation between IGF-1 levels and muscle wasting that Maetsu found:
[...]downregulation of IGF-1 signaling in skeletal muscle played an important role in the wasting effect of Angiotension II. However, the signaling pathways and mechanisms whereby IGF-1 prevents Ang II-induced skeletal muscle atrophy are unknown.[7] Yoshida went on to recommend IGF-1 as a treatment for this muscle wasting.
Yang, et al, corroborate the potential of IGF-1 as an anti-wasting agent:
It was found that H(2)O(2) diminishes muscle cell viability and induces a case-independent apoptotic cell death. Pretreatment with IGF-I protects muscle cells from H(2)O(2)-induced cell death and enhances muscle cells survival. [10] Protecting muscle cells from oxidative damage presents a potential application in the treatment of the muscle wasting, which appears in many muscle pathologies including Duchenne muscle dystrophy and sarcopenia [age-related muscle loss]. [10]
As noted previously, IGF-1 acts in nearly every cell in the body, which makes it widely applicable to treat wounds of various types. Results of a study by Kim, et al, "suggest that IGF-1 gene therapy may be applied to corpus cavernosum regeneration. Insulin-like growth factor-1 (IGF-1) promotes the proliferation of penile cavernous smooth muscle cells in the rats. ..." [8]
It is very important to note that not only do the tissue type (and cell type), as well as type of IGF and dosage, matter greatly in outcome, but also the particular environment in which the ligand is administered or released. As demonstrated above, the ligand binds preferentially to injured tissue and plays very different roles in different situations; Shavlakadze, et al, drive home this point with a study demonstrating that rats with transgenically altered IGF-1 production levels have greatly increased hypertrophy but only with proper growth stimulus:
"...transgenic mice have increased muscle levels of IGF-1 (approximately 13-26 fold) and show striking muscle hypertrophy (approximately 24-56% increase in mass). ...data demonstrate that elevated IGF-1 has a hypertrophic effect on skeletal muscle only in growth situations." [9]
Cititations:
[1] Targeted Expression of IGF-1 Transgene to Skeletal Muscle Accelerates Muscle and Motor Neuron Regeneration, Eric D. Rabinovsky, The FASEB Journal Express Article doi:10.1096/fj.02-0183fje
[2] Lecture: A novel IGF:IGFBP:vitronectin complex for treatments of wounds, Z. Upton, Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Brisbane, Queensland, Australia
[3] Growth factor delivery methods in the management of sports injuries: the state of play, L Creaney and B Hamilton, Br J Sports Med
[4] - Hameed, M., Lange, K.H., Andersen, J.L., Schjerling, P., Kjaer, M., Harridge, S.D., Goldspink, G., 2004. The effect of recombinant human growth hormone and resistance training on IGF-I mRNA expression in the muscles of elderly men. J. Physiol. 555, 231-240.
[5] - Iida, K., Itoh, E., Kim, D.S., del Rincon, J.P., Coschigano,K.T., Kopchick, J.J., Thorner, M.O., 2004. Muscle mechano growth factor is preferentially induced by growth hormone in growth hormone-deficient lit/lit mice. J. Physiol. 560, 341-349.
[6] Mäestu J, Eliakim A, Jürimäe J, Valter I, Jürimäe T. Anabolic and
Catabolic Hormones and Energy Balance of the Male Bodybuilders During the Preparation for the Competition. J Strength Cond Res. 2010 Mar 17.
[7]Yoshida T, Semprun-Prieto L, Sukhanov S, Delafontaine P. IGF-1 prevents Ang II-induced skeletal muscle atrophy via Akt- and Foxo-dependent inhibition of the ubiquitin ligase Atrogin-1 expression. Am J Physiol Heart Circ Physiol. 2010 Mar 12.
[8] Kim M, Hwang EC, Park IK, Park K. Insulin-like Growth Factor-1 Gene Delivery May Enhance the Proliferation of Human Corpus Cavernosal Smooth Muscle Cells. Urology. 2010 Mar 4.
[9] Shavlakadze T, Chai J, Maley K, Cozens G, Grounds G, Winn N, Rosenthal N, Grounds MD. A growth stimulus is needed for IGF-1 to induce skeletal muscle hypertrophy in vivo. J Cell Sci. 2010 Mar 15.
[10]Yang SY, Hoy M, Fuller B, Sales KM, Seifalian AM, Winslet MC. Pretreatment with insulin-like growth factor I protects skeletal muscle cells against oxidative damage via PI3K/Akt and ERK1/2 MAPK pathways. Lab Invest. 2010 Mar;90(3):391-401.
[11]Dunshea FR, Chung CS, Owens PC, Ballard JF, Walton PE. Insulin-like growth factor-I and analogues increase growth in artificially-reared neonatal pigs. Br J Nutr. 2002 Jun;87(6):587-93.
[12]Gunnell D, Miller LL, Rogers I, Holly JM; ALSPAC Study Team. (2005). Association of insulin-like growth factor I and insulin-like growth factor-binding protein-3 with intelligence quotient among 8- to 9-year-old children in the Avon Longitudinal Study of Parents and Children. Pediatrics. Nov;116(5):e681-6.
The latter article is intended for educational / informational purposes only. THIS PRODUCT IS INTENDED AS A RESEARCH CHEMICAL ONLY. This designation allows the use of research chemicals strictly for in vitro testing and laboratory experimentation only. Bodily introduction of any kind into humans or animals is strictly forbidden by law.
Below is some IGF-1 LR3 info I have come across from all over the net to prepare for to use it this summer. I thought I would share some of my consolidated (and non-original) posts from all over the net. Just to be clear, I am not claiming ownership for any of this information.
Uses
Potential benefits of IGF-1 LR3
· Increased muscle growth
· Decreased body fat
· Increased nutrient shuttling capacity
· Increased muscle pumps
· Increased muscle fullness
· The ability to cause muscle cell hyperplasia
· Regeneration of nerve tissue
Reconstitution
Reconstitution is simply the addition of the 0.6% AA to your lyophilized IGF-1.
Assumption: 1mg/mL IGF-1/AA (1mg IGF-1 will be combined with 1mL AA; 1mg IGF-1 is the same as 1,000mcg). 0.6%AA can easily be found online or can be created using Vinegar (google it).
When reconstituted with AA, IGF-1LR3 is stable for about
1. Swab the top of your IGF-1 vial with a sterile alcohol prep pad
2. Swab the top of your 0.6% AA vial with a sterile alcohol prep pad
3. Using either multiple insulin syringe volumes (example: 2 x 0.5cc) or a single large syringe, obtain 1.0mL of 0.6% AA.
4. In the IGF-1 vial, insert a sterile ~20 ga. needle to act as a vent
5. Inject the 1.0mL of AA very slowly and dribble it down the side of the vial.
a. Be very careful with this peptide as it is very delicate!
6. Remove the needle & syringe and discard
7. Gently swirl the vial or roll between your hands.
a. Again, be very gentle here
8. You now have 1mg/mL of IGF-1
a. This is the same as: 1,000mcg/mL
Notes:
1. If you added 2mL of AA, it would be a 0.5mg/mL
Back-Loading With Bacteriostatic Water (BW)
Back-loading is a process in which you dilute the IGF-1/AA solution that is in your syringe. The point is to dilute the acidity to a point that it will no longer cause tissue necrosis (death/damage) or pain upon injection. It is recommended to dilute no less than 4:1 (4 parts BW to 1 part IGF-1/AA).
Example: If you are injecting 40mcg bilat, IM, you will have two syringes each with 20mcg IGF-1. Assume you want to draw 2 IU IGF-1. You will draw 2 IUs of the IGF-1/AA solution, then draw 2x4 = 8 IUs of BW (four times the amount of IGF-1/AA solution). The total number of IUs in each syringe will be 2 + 8 = 10 IUs. It will not hurt you if you decide to back-load with more BW. It is a personal preference. Injection Directions
1. Wash your hands thoroughly
2. Optional: put on exam gloves and rub with IPA until dry
3. Using an alcohol swab, clean the tops of both the IGF-1 vial and the BW vial.
4. Using a fresh alcohol swab, thoroughly clean the injection sites (let dry)
5. Fill each syringe with the appropriate amount of IGF-1/AA solution
a. Do NOT touch the needles to anything but sterile surfaces!
b. It is recommended that you clean/sanitize the area/surfaces you’re working in, in case you mindlessly touch a needle to a table (or other area).
6. Back-loading: Draw up the necessary amount of BW into each syringe.
a. Tilt the needle up and down so the bubble(s) rise and fall, which mixes the solution slightly
7. With the needle pointing up, flick the syringe body to get the bubbles to rise to the needle
8. Slowly expel the air; be careful to not quirt liquid out as this wastes IGF-1
a. It takes >3mL of air to cause harm; small volumes of accidentally injected air will most likely be absorbed by muscle tissue
9. Insert syringe and aspirate by slightly pulling up on the plunger to see if you have hit a vessel. If you see blood, remove needle, and try again (no need to change syringes). If you do NOT see blood, proceed to inject.
10. Perform “7.” thru “9” above on other side.
11. Discard sharps in appropriate container
Stability
Stability at room temp after reconstituting with AA is probably a few years
Reconstituting in BAC it has a stability of only a few hours at room temp and a month refrigerated.
In powder form, it should be good for a long time.
Storage Condition: -20 C (-4 F)
Biological Potency No Change up to 2 years
Immunological Activity No Change up to 2 years
Mobility of Protein No Change up to 2 years
Elution Profile by reversed phased HPLC No Change up to 2 years
Storage Condition: +4 C (39.2 F)
Biological Potency No Change up to 2 years
Immunological Activity No Change up to 2 years
Mobility of Protein No Change up to 2 years
Elution Profile by reversed phased HPLC No Change up to 2 years
Storage Condition: +22 C (71.6 F)
Biological Potency No Change up to 2 years
Immunological Activity No Change up to 2 years
Mobility of Protein No Change up to 2 years
Elution Profile by reversed phased HPLC No Change up to 2 years
Storage Condition: +37 C (98.6 F)
Biological Potency No Change up to 1 year
Immunological Activity No Change up to 1 year
Mobility of Protein No Change up to 1 year
Elution Profile by reversed phased HPLC No Change up to 1 year
Dosing
Dose per injection: 40-80mcg
Injections per vial: 20 @ 50mcg dosages
Amount to Inject: If you have used 1ml of water for mixing then a 50mcg dosage = 0.05ml (or 5 units on Insulin Syringe). If you have used 2ml of water for mixing then 50mcg = 0.10ml (or 10 units) and if you have used 3ml of water for mixing, then 50mcg = 0.15ml (or 15 units).
Can be injected pre or post workout.
Many choose to pin bilaterally hoping for a localized effect (for example 25mcg right and left biceps) however, with the long active life of IGF-1 LR3, it is most likely the affect will be systemic.
Research
The insulin-like growth factors (IGFs) are peptides with sequence similarities to insulin. IGF-1 is mainly secreted by the liver via stimulation of GH (growth hormone); this is the primary mechanism of what is known as the IGF/GH axis.. IGF-1 plays a role in both normal, healthy bodily processes as well as other disease states. Because it plays roles in both cell proliferation and inhibition of apoptosis, IGF-1 is important for both normal and abnormal cell growth. Creaney and Hamilton write the following on the topic of IGF-1 and its role in the body, as well as its potential in diagnosing certain disorders:
IGF-1 is a 7.5 kDa polypeptide that is structurally similar to insulin.50 It induces proliferation, differentiation and hypertrophy of multiple cell lines, in particular skeletal muscle, and has an additional role of facilitating glucose entry into skeletal muscle cells... IGF-1 is secreted as the result of a hypothalamic-pituitary liver axis. The hypothalamus secretes growth hormone-releasing hormone (GHRH), which stimulates the pituitary to release growth hormone, which in turn stimulates the liver to release IGF-1. Like most endocrine systems, the system is controlled by negative feedback, thus in normal individuals, exogenous administration of IGF-1 will lead to suppression of the axis. Whereas growth hormone secretion is pulsatile, with greatly varying levels in a 24-hour period, serum IGF-1 levels are relatively stable within a 24-hour period; hence, measurement of the serum IGF-1 level is now the favoured test for acromegaly or growth hormone deficiency.[3]
High IGF-1 levels are correlated with higher levels of lean body mass. Neuroprotective, myelinatory, synaptogenic, and anti-catabolic effects of IGF-1 are well-documented in human and animal study subjects. Serum IGF-1 levels correlate positively to higher IQ in children. [12]
IGF-1 is also manufactured in skeletal muscle. A form of IGF-1 known as IGF-1 LR3, when applied from an exogenous source, has been shown to circulate longer and bind to more targets in the body than regular IGF-1 as the body manufactures it; further, Dunshea finds that "long arginine (LR3) IGF-I, has been shown to be more potent than IGF-I in the rat."[11]
Exogenous IGF-1 has been shown to "increase muscle mass and promote muscle cell proliferation, differentiation, and survival." [10] For this reason, IGF-1 is of great interest to current researchers... IGF-1 affects nearly every cell in the human body.
IGF-1 is a candidate for being used as a neurotrophic agent in what is known as gene therapy to effect new nerve growth in victims of severe trauma who experience nerve damage and related symptoms. [1] Even though microsurgical techniques have improved vastly in the past decade, IGF-1 offers great potential as a concurrent treatment in addition to current microsurgical techniques due to its ability to not only generate new nerve growth (neurotrophy) but also to promote proliferation of muscle cells in damaged areas. IGF-1 also acts as a survival factor for spinal cord motor neurons, increasing its potential further. [1]
Rabinovsky writes that "nerve sprouting within skeletal muscles is an essential restorative process in response to an injury or a pathological condition. IGF-1 increases intramuscular nerve sprouting 10-fold when administered subcutaneously to normal adult rats" and also that "IGF-1 is also a potent myogenic factor, promoting myoblast proliferation, myogenic differentiation, and myotube hypertrophy." [1] Rabinovsky's own studies show that "when the sciatic nerve is injured,increased local expression of IGF-1 in muscle hastens motor nerve and muscle repair." [1]
Upton et al, "assessed the [IGF-1] complexes as a topical agent in wound healing studies conducted in 3-dimensional in vitro human skin equivalent models, as well as in the treatment of deep partial thickness wounds in two different porcine models. This has revealed that the VN:IGF-I:IGFBP complexes hold promise as a wound healing therapy." [2] Of interest to other researchers is that significant positive results "were obtained with nanogram doses of growth factors." [2] IGF-1 plays an integral role in the body's own healing process and binds more strongly to damaged tissue. Other researchers have found that without a hypertrophy stimulus, the muscle-building effects of IGF-1 are unrealized; this is likely for the same reason that Upton et al found injured tissue strongly attracts IGF-1 binding.In fact, IGF-1 is not even released from skeletal tissue in the absence of exercise. [3]
IGF-1 is well-studied and there is a research consensus on its effectiveness for "healing of tendon and muscle injuries. According to Creaney and Hamilton, "IGF-1 has been used in isolation by a number of investigators. Animal studies have suggested a role for IGF-1 in both the acceleration and enhancement of healing of tendon and muscle injuries" [3]
Maetsu et al, in a study on IGF-1 levels in bodybuilders in competition condition, found "data [to] indicate that severe energy restriction to extremely low body energy reserves decreases significantly the concentrations of 3 anabolic pathways despite high protein intake." Maetsu concludes that "Monitoring of insulin and IGF-1 concentration is suggested to prevent losses in muscle mass in energy-restricted conditions" and that "other nutritional strategies might be needed to prevent possible catabolic effect during preparation of bodybuilders to competition." [6]
Yoshida, et al, demonstrate the converse side of the negative correlation between IGF-1 levels and muscle wasting that Maetsu found:
[...]downregulation of IGF-1 signaling in skeletal muscle played an important role in the wasting effect of Angiotension II. However, the signaling pathways and mechanisms whereby IGF-1 prevents Ang II-induced skeletal muscle atrophy are unknown.[7] Yoshida went on to recommend IGF-1 as a treatment for this muscle wasting.
Yang, et al, corroborate the potential of IGF-1 as an anti-wasting agent:
It was found that H(2)O(2) diminishes muscle cell viability and induces a case-independent apoptotic cell death. Pretreatment with IGF-I protects muscle cells from H(2)O(2)-induced cell death and enhances muscle cells survival. [10] Protecting muscle cells from oxidative damage presents a potential application in the treatment of the muscle wasting, which appears in many muscle pathologies including Duchenne muscle dystrophy and sarcopenia [age-related muscle loss]. [10]
As noted previously, IGF-1 acts in nearly every cell in the body, which makes it widely applicable to treat wounds of various types. Results of a study by Kim, et al, "suggest that IGF-1 gene therapy may be applied to corpus cavernosum regeneration. Insulin-like growth factor-1 (IGF-1) promotes the proliferation of penile cavernous smooth muscle cells in the rats. ..." [8]
It is very important to note that not only do the tissue type (and cell type), as well as type of IGF and dosage, matter greatly in outcome, but also the particular environment in which the ligand is administered or released. As demonstrated above, the ligand binds preferentially to injured tissue and plays very different roles in different situations; Shavlakadze, et al, drive home this point with a study demonstrating that rats with transgenically altered IGF-1 production levels have greatly increased hypertrophy but only with proper growth stimulus:
"...transgenic mice have increased muscle levels of IGF-1 (approximately 13-26 fold) and show striking muscle hypertrophy (approximately 24-56% increase in mass). ...data demonstrate that elevated IGF-1 has a hypertrophic effect on skeletal muscle only in growth situations." [9]
Cititations:
[1] Targeted Expression of IGF-1 Transgene to Skeletal Muscle Accelerates Muscle and Motor Neuron Regeneration, Eric D. Rabinovsky, The FASEB Journal Express Article doi:10.1096/fj.02-0183fje
[2] Lecture: A novel IGF:IGFBP:vitronectin complex for treatments of wounds, Z. Upton, Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Brisbane, Queensland, Australia
[3] Growth factor delivery methods in the management of sports injuries: the state of play, L Creaney and B Hamilton, Br J Sports Med
[4] - Hameed, M., Lange, K.H., Andersen, J.L., Schjerling, P., Kjaer, M., Harridge, S.D., Goldspink, G., 2004. The effect of recombinant human growth hormone and resistance training on IGF-I mRNA expression in the muscles of elderly men. J. Physiol. 555, 231-240.
[5] - Iida, K., Itoh, E., Kim, D.S., del Rincon, J.P., Coschigano,K.T., Kopchick, J.J., Thorner, M.O., 2004. Muscle mechano growth factor is preferentially induced by growth hormone in growth hormone-deficient lit/lit mice. J. Physiol. 560, 341-349.
[6] Mäestu J, Eliakim A, Jürimäe J, Valter I, Jürimäe T. Anabolic and
Catabolic Hormones and Energy Balance of the Male Bodybuilders During the Preparation for the Competition. J Strength Cond Res. 2010 Mar 17.
[7]Yoshida T, Semprun-Prieto L, Sukhanov S, Delafontaine P. IGF-1 prevents Ang II-induced skeletal muscle atrophy via Akt- and Foxo-dependent inhibition of the ubiquitin ligase Atrogin-1 expression. Am J Physiol Heart Circ Physiol. 2010 Mar 12.
[8] Kim M, Hwang EC, Park IK, Park K. Insulin-like Growth Factor-1 Gene Delivery May Enhance the Proliferation of Human Corpus Cavernosal Smooth Muscle Cells. Urology. 2010 Mar 4.
[9] Shavlakadze T, Chai J, Maley K, Cozens G, Grounds G, Winn N, Rosenthal N, Grounds MD. A growth stimulus is needed for IGF-1 to induce skeletal muscle hypertrophy in vivo. J Cell Sci. 2010 Mar 15.
[10]Yang SY, Hoy M, Fuller B, Sales KM, Seifalian AM, Winslet MC. Pretreatment with insulin-like growth factor I protects skeletal muscle cells against oxidative damage via PI3K/Akt and ERK1/2 MAPK pathways. Lab Invest. 2010 Mar;90(3):391-401.
[11]Dunshea FR, Chung CS, Owens PC, Ballard JF, Walton PE. Insulin-like growth factor-I and analogues increase growth in artificially-reared neonatal pigs. Br J Nutr. 2002 Jun;87(6):587-93.
[12]Gunnell D, Miller LL, Rogers I, Holly JM; ALSPAC Study Team. (2005). Association of insulin-like growth factor I and insulin-like growth factor-binding protein-3 with intelligence quotient among 8- to 9-year-old children in the Avon Longitudinal Study of Parents and Children. Pediatrics. Nov;116(5):e681-6.
The latter article is intended for educational / informational purposes only. THIS PRODUCT IS INTENDED AS A RESEARCH CHEMICAL ONLY. This designation allows the use of research chemicals strictly for in vitro testing and laboratory experimentation only. Bodily introduction of any kind into humans or animals is strictly forbidden by law.