drtbear1967
Musclechemistry Board Certified Member
Great information from Presser.
If you had to chose between IGF and HGH for the purposes of bodybuilding and overall health and longevity, then IGF wins hands down no contest! is there a place for HGH along side IGF, yes there is if you can afford to run both!
Growth factors are proteins that bind to receptors on the cell surface, with the primary result of activating cellular proliferation and/or differentiation. Many growth factors are quite versatile, stimulating cellular division in numerous different cell types; while others are specific to a particular cell-type.
Cytokines are a class of signaling proteins that are used extensively in cellular communication, immune function and embryogenesis. Cytokines are produced by a variety of hematopoietic and non-hematopoietic cell types and can exert autocrine, paracrine and endocrine effects as do the hormones. They are, therefore, more correctly related to hormones than to growth factors in their overall functions. However, many cytokines also exhibit growth factor activity so they are discussed here as well as in the Peptide Hormones page.The lists in the following Tables as well as the descriptions of several factors are not intended to be comprehensive nor complete but a look at some of the more commonly known factors and their principal activities.
Growth Factors
[TABLE="class: cms_table"]
<tbody>[TR]
[TD="class: cms_table_tableheads, bgcolor: #CCCCCC, align: center"]Factor[/TD]
[TD="class: cms_table_tableheads, bgcolor: #CCCCCC, align: center"]Principal Source[/TD]
[TD="class: cms_table_tableheads, bgcolor: #CCCCCC, align: center"]Primary Activity[/TD]
[TD="class: cms_table_tableheads, bgcolor: #CCCCCC, align: center"]Comments[/TD]
[/TR]
[TR]
[TD="align: center"]PDGF[/TD]
[TD]platelets, endothelial cells, placenta[/TD]
[TD]promotes proliferation of connective tissue, glial and smooth muscle cells[/TD]
[TD]represents a family of four peptides encoded by four distinct genes: A, B, C, and D; these four peptides form either homo- or heterodimers such that five distinct biologically active PDGF isoforms (AA, AB, BB, CC, DD) result[/TD]
[/TR]
[TR]
[TD="align: center"]EGF[/TD]
[TD]submaxillary gland, Brunners gland[/TD]
[TD]promotes proliferation of mesenchymal, glial and epithelial cells[/TD]
[TD]represents the founding member of the EGF-family of proteins that includes, but is not limited to, transforming growth factor-α (TGF-α), amphiregulin, and the neuregulins (neuregulin-1, -2, -3, and -4)[/TD]
[/TR]
[TR]
[TD="align: center"]TGF-α[/TD]
[TD]macrophages, keratinocytes, hypothalamic astrocytes; commonly expressed by transformed cells[/TD]
[TD]important for normal wound healing, cellular proliferation, female reproductive maturation, embryogenesis[/TD]
[TD]is a member of the EGF-family of proteins; functions by binding to the EGF receptor[/TD]
[/TR]
[TR]
[TD="align: center"]FGF[/TD]
[TD]wide range of cells; protein is associated with the ECM[/TD]
[TD]promotes proliferation of many cells; inhibits some stem cells; induces mesoderm to form in early embryos[/TD]
[TD]at least 18 family members, 5 distinct receptors[/TD]
[/TR]
[TR]
[TD="align: center"]NGF[/TD]
[TD]mast cells, eosinophils, bone marrow stromal cells, keratinocytes[/TD]
[TD]promotes neurite outgrowth and neural cell survival[/TD]
[TD]member of a family of proteins termed neurotrophins that promote proliferation and survival of neurons; neurotrophin receptors are a class of related proteins first identified as proto-oncogenes: TrkA ("trackA"), TrkB, TrkC[/TD]
[/TR]
[TR]
[TD="align: center"]Erythropoietin[/TD]
[TD="align: center"]kidney[/TD]
[TD]promotes proliferation and differentiation of erythrocytes[/TD]
[TD][/TD]
[/TR]
[TR]
[TD="align: center"]TGF-β[/TD]
[TD]activated Th1 cells (T-helper) and natural killer (NK) cells[/TD]
[TD]anti-inflammatory (suppresses cytokine production and class II MHC expression), promotes wound healing, inhibits macrophage and lymphocyte proliferation[/TD]
[TD]at least 100 different family members[/TD]
[/TR]
[TR]
[TD="align: center"]IGF-1[/TD]
[TD="align: center"]primarily liver[/TD]
[TD]promotes proliferation of many cell types[/TD]
[TD]related to IGF-2 and proinsulin, also called somatomedin C[/TD]
[/TR]
[TR]
[TD="align: center"]IGF-2[/TD]
[TD="align: center"]variety of cells[/TD]
[TD]promotes proliferation of many cell types primarily of fetal origin[/TD]
[TD]related to IGF-1 and proinsulin[/TD]
[/TR]
</tbody>[/TABLE]
If you had to chose between IGF and HGH for the purposes of bodybuilding and overall health and longevity, then IGF wins hands down no contest! is there a place for HGH along side IGF, yes there is if you can afford to run both!
Growth factors are proteins that bind to receptors on the cell surface, with the primary result of activating cellular proliferation and/or differentiation. Many growth factors are quite versatile, stimulating cellular division in numerous different cell types; while others are specific to a particular cell-type.
Cytokines are a class of signaling proteins that are used extensively in cellular communication, immune function and embryogenesis. Cytokines are produced by a variety of hematopoietic and non-hematopoietic cell types and can exert autocrine, paracrine and endocrine effects as do the hormones. They are, therefore, more correctly related to hormones than to growth factors in their overall functions. However, many cytokines also exhibit growth factor activity so they are discussed here as well as in the Peptide Hormones page.The lists in the following Tables as well as the descriptions of several factors are not intended to be comprehensive nor complete but a look at some of the more commonly known factors and their principal activities.
Growth Factors
[TABLE="class: cms_table"]
<tbody>[TR]
[TD="class: cms_table_tableheads, bgcolor: #CCCCCC, align: center"]Factor[/TD]
[TD="class: cms_table_tableheads, bgcolor: #CCCCCC, align: center"]Principal Source[/TD]
[TD="class: cms_table_tableheads, bgcolor: #CCCCCC, align: center"]Primary Activity[/TD]
[TD="class: cms_table_tableheads, bgcolor: #CCCCCC, align: center"]Comments[/TD]
[/TR]
[TR]
[TD="align: center"]PDGF[/TD]
[TD]platelets, endothelial cells, placenta[/TD]
[TD]promotes proliferation of connective tissue, glial and smooth muscle cells[/TD]
[TD]represents a family of four peptides encoded by four distinct genes: A, B, C, and D; these four peptides form either homo- or heterodimers such that five distinct biologically active PDGF isoforms (AA, AB, BB, CC, DD) result[/TD]
[/TR]
[TR]
[TD="align: center"]EGF[/TD]
[TD]submaxillary gland, Brunners gland[/TD]
[TD]promotes proliferation of mesenchymal, glial and epithelial cells[/TD]
[TD]represents the founding member of the EGF-family of proteins that includes, but is not limited to, transforming growth factor-α (TGF-α), amphiregulin, and the neuregulins (neuregulin-1, -2, -3, and -4)[/TD]
[/TR]
[TR]
[TD="align: center"]TGF-α[/TD]
[TD]macrophages, keratinocytes, hypothalamic astrocytes; commonly expressed by transformed cells[/TD]
[TD]important for normal wound healing, cellular proliferation, female reproductive maturation, embryogenesis[/TD]
[TD]is a member of the EGF-family of proteins; functions by binding to the EGF receptor[/TD]
[/TR]
[TR]
[TD="align: center"]FGF[/TD]
[TD]wide range of cells; protein is associated with the ECM[/TD]
[TD]promotes proliferation of many cells; inhibits some stem cells; induces mesoderm to form in early embryos[/TD]
[TD]at least 18 family members, 5 distinct receptors[/TD]
[/TR]
[TR]
[TD="align: center"]NGF[/TD]
[TD]mast cells, eosinophils, bone marrow stromal cells, keratinocytes[/TD]
[TD]promotes neurite outgrowth and neural cell survival[/TD]
[TD]member of a family of proteins termed neurotrophins that promote proliferation and survival of neurons; neurotrophin receptors are a class of related proteins first identified as proto-oncogenes: TrkA ("trackA"), TrkB, TrkC[/TD]
[/TR]
[TR]
[TD="align: center"]Erythropoietin[/TD]
[TD="align: center"]kidney[/TD]
[TD]promotes proliferation and differentiation of erythrocytes[/TD]
[TD][/TD]
[/TR]
[TR]
[TD="align: center"]TGF-β[/TD]
[TD]activated Th1 cells (T-helper) and natural killer (NK) cells[/TD]
[TD]anti-inflammatory (suppresses cytokine production and class II MHC expression), promotes wound healing, inhibits macrophage and lymphocyte proliferation[/TD]
[TD]at least 100 different family members[/TD]
[/TR]
[TR]
[TD="align: center"]IGF-1[/TD]
[TD="align: center"]primarily liver[/TD]
[TD]promotes proliferation of many cell types[/TD]
[TD]related to IGF-2 and proinsulin, also called somatomedin C[/TD]
[/TR]
[TR]
[TD="align: center"]IGF-2[/TD]
[TD="align: center"]variety of cells[/TD]
[TD]promotes proliferation of many cell types primarily of fetal origin[/TD]
[TD]related to IGF-1 and proinsulin[/TD]
[/TR]
</tbody>[/TABLE]
Last edited by Presser; 08-05-2016 at 03:14 PM.