HGH-composition chemical makeup and regulation
The human growth hormone, as we all know is a protein compound. Basically it is a protein based poly peptide hormone which is synthesized by the somatotroph cells inside the brain. The structure of this hormone is much more complex than the normal protein based derivatives. It has a much more complex pattern of arrangement and the primary, secondary and tertiary structures of the protein are completely different from each other and so is the functions of the structures. They are tangled and made in a form of a coil for compactness in storage.
The major isoform of the growth hormone is a protein of 191 amino acids and has a molecular weight of the protein is approximately about 22,124 Daltons. The structure consists of four helices necessary for the interaction with the GH receptor. In structure we find that the GH is similar to that of prolactin and somatomammotropin. In other words GH is homologous to these 2 hormones. Despite the different structures of growth hormones in different species, it is only in the primates that this hormone in growth has significant results. Its chemical makeup however is similar to that of proteins. The growth hormone is produced in specific amounts by the pituitary gland so as to defend the body from any defective growth.
How is this regulated?
Well it is very amusing to look at how a small gland in the brain controls so much growth and metabolism inside the body. There is a even more elaborate procedure by which the secretion of GH is regulated. The peptides released by the neurosecretary nuclei of the hypothalamus into the hypophyseal portal venous blood surrounding the pituitary are the major controllers of GH secretion by the somatotropes. But also the secretion of the GH is regulated by more than one mechanism. Stimulators of GH include peptide hormones such as growth hormone releasing hormone (GNHR), sex hormones – androgens in males and estrogen in females. When the sex hormones are considered they increase the secretion of the GH for a short period of time since, once the puberty is reached, the GH is required to help for the secondary growth of the male or females. Also deep sleep, fasting and vigorous exercise can help in regulation and secretion of the growth hormone.
On the other hand when the GH level inside the body become intolerable there has to be mechanisms which inhibit the GH levels so that the body doesn’t face any issues. The inhibitors of GH secretion are-
- Somatostatin from the periventricular nucleus.
- Hyperglycemia
- Glucocorticoids
- Dihydrotestosterone
Also foreign products in the body can have an impact on the normal functioning of the GH secretion.