The Role of GH and IGF-1 in Mechanisms of Aging

Dehydroepiandrosterone (DHEA) is found naturally in the human body, produced primarily by the adrenal glands.Scientists have developed various models for applying and visualizing the roles of GH/IGF-1 in the way a human body ages. There have been lot of critiques to the model. Precise roles of GH and IGH-1 still remain to be found out as they are uncertain. IGF-1 has always been understood as an important mitogen and has the potential to contribute to neoplasia and other potentially serious age related diseases. IGF-1 builds muscle and increases satellite cell expression while burning fat. This is what makes growth hormone worth the 300-400 dollars per week the professionals spend on a cycle, even before IGF-1 was available. Age-related pathological research has revealed that IGF-1 can contribute to moderate caloric restriction. Experiments were done on rats and found out that those rats having low levels of IGF-1 were calorically restricted and were also resistant to p-cristine induced bladder cancer. More studies regarding the different species of mice were done and found out that there is and extended latency for the tumors to form.

Scientists believe that IGF-1 is required for some types of chemically induced pathogenesis. Though, nothing can be said concretely regarding the role of GH deficiency in aging mechanism , most experts agree that the scientific findings till date have shown very intersting results which just mean that further studies on growth hormone and hgh can lead to some outstanding medications for anti aging purposes. As the results speak, it has been concluded that primary result of GH/IGF-1 deficiency is the slowing of a central "biological clock" and this is seen as an age-related pathology and also proposed by others.

Other areas of studies are:-  biological aging, immune function, increased collagen cross linking, behavioral aging, cognitive ability. These are some of the aspects that the medical community has been trying to analyze and form a relationship between them and GH/IGF-1. Experts agree that lower amounts of GH as the body ages results in negative effects in almost all of the above aspects and there are serious consequences. Although no solid medical paper has aggressively proved the consequences of GH/IGF-1 deficiency on aging. Any evidence that GH/IGF-1 deficiency delays biological aging must be accompanied with lots of literature and experimental findings demonstrating beneficial actions of the hormones in young and old animals.

Growth Hormone(GH) : It is produced in the anterior pituitary and regulated by two hypothalamic hormones, growth hormone-releasing hormone (GHRH), which stimulates both the synthesis and secretion of GH; and somatostatin (SS). GH also feeds back to inhibit GHRH secretion and probably has a direct inhibitory effect on secretion from the somatotroph (GH-producing cells) and has many anti aging benefits. GH has the tendency to bind to its receptor which is found in tissues through out the body. When this receptor is activated, stimulation of synthesis and secretion of Insulin Like Growth Factor (IGF-1) takes place.

90% of circulating IGF-1 is synthesized and secreted by the liver. But one thing of note is that some cells like in the brain et. have the capability to produce IGF-1.Binding of the hormone to the IGF-1 receptor causes potent mitogenic effects, including increases in DNA,RNA and protein synthesis. There is heterogeneity  in the processing of IGF-1 and the transcripts appear to produce single peptide which is homologous to the structure of proinsulin.  Blood and tissue levels as well as activity of the peptide are regulated by IGF-1 binding proteins (IGFBP). It was first believed that all actions of GH were mediated through IGF-1  but the direct role of GH in regulation of lipolysis and insulin sensitivity has been now proved by many findings and experimental data.

Links Directory