- 01-12-2008, 04:07 PM
- 01-12-2008, 04:13 PM
trying to find research on it. not finding all that much yet. i am just gonna stick with igf-1, ghrp, hex, pegmgf, etc until i see some more stuff about this.
01-12-2008, 04:20 PM
"Insulin-like growth factor 2 (IGF-2) is thought to be a primary growth factor required for early development while IGF-I expression is required for achieving maximal growth."
I'd only ever thought of IGF-2 as something for gestation.
01-12-2008, 11:24 PM
02-16-2008, 05:37 AM
BigPeteFox used it along w/ IGF-1 and said the fatloss was amazing. I think his thread was taken down at IA at the request of the seller. You might want to PM him about his run & positive experience.
02-25-2008, 12:54 AM
02-25-2008, 01:04 AM
02-25-2008, 11:57 AM
02-25-2008, 12:12 PM
02-25-2008, 06:27 PM
Differential autocrine regulation of intestine epithelial cell proliferation and differentiation by insulin-like growth factor (IGF) system components.
Jehle PM, Fussgaenger RD, Blum WF, Angelus NK, Hoeflich A, Wolf E, Jungwirth RJ.
Department of Internal Medicine II, University Ulm, Germany. [email protected]
The mechanisms which regulate cell turnover in the intestinal epithelium are incompletely understood. The present study was performed to characterize the role of autocrine IGF system components in intestine epithelial cell proliferation and differentiation comparing rapidly growing crypt cells (IEC-6) with differentiating enterocytes (CaCo-2). The autocrine release of IGF-I, IGF-II and IGFBP-1 through -3 was determined by specific RIAs and western ligand blotting. In addition, binding and growth-promoting activity of insulin, IGF-I and IGF-II was investigated. Enterocytic differentiation was assessed by measuring the brush-border enzymes alkaline phosphatase and sucrase. During IEC-6 growth, the autocrine release of IGF-I and -II increased, whereas IGFBP-2 levels decreased. Specific receptors for IGF-I and IGF-II but not insulin could be detected. IGF-I was 100-fold more potent than insulin to stimulate IEC-6 cell proliferation. In contrast, CaCo-2 cells revealed higher binding of insulin than IGF-I/-II and no release of IGF-I. At switch from CaCo-2 cell proliferation to differentiation a marked increase in the secretion of IGF-II (10-fold), IGFBP-1 (2.5-fold), IGFBP-2 (3-fold), and IGFBP-3 (6-fold) was measured. Our data indicate that IGF system components differentially modulate enterocytic cell proliferation and differentiation.
PMID: 10226788 [PubMed - indexed for MEDLINE]
02-26-2008, 12:29 AM
Insulin-like growth factor II (IGF-II) is a 7.5 kDa, 67 amino acid peptide which is thought to mediate some of the actions of growth hormone (GH). IGF-II peptide consists of the A, C, and B chains, and is structurally homologous to IGF-I and proinsulin. IGF-II is secreted by the liver and other tissues and is postulated to have mitogenic and metabolic actions at or near the sites of synthesis; this has been termed the paracrine role of IGF-II. IGF-II also appears in the peripheral circulation, where it circulates primarily in a high molecular weight tertiary complex with IGF-binding protein-3 (IGFBP-3) and acid-labile subunit. A smaller proportion of IGF-II may circulate in association with other IGF-binding proteins. The proportion of unbound IGF-II in the circulation has been estimated at >5%. Plasma levels of IGF-II are dependent upon adequate levels of GH and other factors, including adequate nutrition.
The actions of IGF-II are mediated by binding to specific cell surface receptors. The function of the type II IGF receptor is not completely defined. IGF-II binds with lower affinity to the IGF-I type receptors and the insulin receptors. These latter receptors may mediate the mitogenic and metabolic actions of IGF-II. Although its specific physiologic role has not been defined, it has been postulated that the interplay of IGF-I and IGF-II with the different cell surface receptors and circulating binding proteins modulates tissue growth.
Normal postnatal plasma IGF-II levels are assumed to be at maximum levels, since administration of GH does not result in increased IGF-II levels (unlike IGF-I levels, which increase). Postnatal plasma IGF-II levels show a moderate age-related increase throughout childhood and puberty, and there is no significant variability during the day. IGF-II levels decrease in GH deficiency and in malnutrition. IGF-II levels may also decrease in acromegaly and during exogenous administration of IGF-I.
Gluckman PD, Ambler GR. What is the function of circulating insulin-like growth factor-2 in postnatal life? Mol Cell Endocrinol. 1993; 92(1):C1-C3.
Lee PD, Rosenfeld RG. Clinical utility of insulin-like growth factor assays. Pediatrician. 1987; 14(3):154-161.
Rechler MM. Insulin-like growth factor binding proteins. Vitam Horm. 1993; 47:1-114.
Blum WF, Ranke MB, Bierich JR. A specific radiomimmunoassay for insulin-like growth factor II: The interference of IGF binding proteins can be blocked by excess IGF-I. Acta Endocrinol (Copenh). 1988; 118:374-380.
02-26-2008, 02:27 AM
02-26-2008, 09:25 AM
So igf II is most prevelant during youth/puberty when you see the most physical growth?
A friend of mine claims that igf II will replace igf-I lr3 eventually. He said the key to making this peptide really popular is extending the half life (as was done with igf-I, lr3 as compared to plain igf-I).
02-26-2008, 09:57 AM
02-26-2008, 10:52 AM
02-26-2008, 11:18 PM
Grunt happens to be Da Man when it comes to peptides..
I didn't use it with Lr3.. It stung in the site (calves), and I didn't notice much while on, not until I was done pretty much like Lr3..
I don't even remember much of that, it was barely a 2wk trial dose, I can't remember if it was 10 or 15mcg I used.. I didn't have amazing gains/losses from it, although I did lean out abit the second week and for a time after..
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