Somatotropin, also known as growth hormone, plays a pivotal role in human growth and development. Endocrinologists and researchers have been studying this protein hormone to better understand its functions, its involvement in various diseases, and how it can be applied in medicine, notably in hormone replacement therapy and oncology treatments.
Background of Somatotropin
The existence of Somatotropin was first noted in the early 20th century, but it was not until 1956 that its protein structure was discovered. Found within the pituitary gland, Somatotropin's gene is located on chromosome 17, specifically at locus 17q22-24. The protein structure comprises 191 single-chain amino acids with a molecular weight of approximately 22,000 Daltons.
Somatotropin Function
Somatotropin plays a significant role in growth control. It influences both the growth of all tissues, including bone, and the metabolism of fats and carbohydrates. It stimulates the liver production of insulin-like growth factor 1 (IGF-1), which subsequently stimulates the growth of bones and other tissues.
Somatotropin-Related Signaling Pathways
Several signaling pathways are pertinent in carrying out Somatotropin’s functions. The Janus Kinase (JAK)/Signal Transducer and Activator of Transcription (STAT) pathway is Somatotropin's main signaling route, linking growth hormone at the cell surface to the nucleus. It results in the transcription of growth hormone-responsive genes like IGF-1. Additionally, the MAPK/ERK pathway mediates the transduction of many cellular responses like proliferation and differentiation. Lastly, the PI3K/Akt signaling pathway regulates multiple cellular processes, including metabolism, growth, proliferation, survival, and angiogenesis.
Somatotropin Related Diseases
While the afore-mentioned pathways play essential roles under standard conditions, disruptions lead to related diseases and conditions. Overproduction of the hormone can lead to gigantism in children and acromegaly in adults – conditions characterized by excessive growth of body tissues.
On the flip side, deficiencies in Somatotropin result in stunted growth, known as growth hormone deficiency (GHD). This can be congenital due to a genetic mutation or can be acquired later in life because of a tumor or injury. Notably, people with this deficiency are shorter and may have a higher body fat percentage compared to those with normal hormone levels.
The Application of Somatotropin in Medicine
Somatotropin's primary medical application is in the treatment of children and adults with growth hormone deficiency. Individuals with GHD are administered with human growth hormone (HGH), a synthetic form of Somatotropin, to stimulate growth and cell reproduction. Additionally, it is used in treating short bowel syndrome, muscle wasting HIV patients, and some cases of the Turner syndrome, where females don’t mature sexually and grow normally due to an absent or incomplete X chromosome.
List of Drug Candidates related to Somatotropin
Various synthetic versions of Somatotropin, approved as drug candidates by the U.S. Food and Drug Administration (FDA), are available today. These include Somatropin (Genotropin, Humatrope, Norditropin, Nutropin, Saizen, Serostim, Zomacton, Zorbtive). CJC-1295 Sermorelin/GHRH HGH fragment 176-191
In conclusion, Somatotropin is an essential hormone for growth and metabolism. Its comprehensive understanding has allowed its intervention in treating growth-related disorders. However, like all potent biological substances, it is a double-edged sword, proving beneficial when used appropriately but harmful when misused. Hence the need for judicious use and constant monitoring. In line with our growing comprehension of its intricate functions and relationships, additional applications, related drugs, and therapies will undoubtedly be developed.