A protein hormone is a chemical messenger, produced by the body, that is made of protein or peptides (short chains of amino acids). These hormones play vital roles in regulating numerous bodily functions. They are also known as peptide hormones. Unlike the rapid signaling of the nervous system, protein hormone responses are slower. They exert their effects by binding to specific receptors on target cells.
How Protein Hormones Work:
- Synthesis and Release: Protein hormones are synthesized within endocrine glands and stored in secretory granules before release into the bloodstream.
- Transport: They travel through the bloodstream to reach their target cells throughout the body.
- Receptor Binding: Protein hormones bind to specific receptors located on or within the target cells. This binding triggers a cascade of intracellular events.
- Cellular Response: The activated receptors initiate various cellular responses, including changes in gene expression, metabolism, and cell growth. These responses are essential for maintaining homeostasis.
Examples of Protein Hormones:
- Growth Hormone (GH): Released from the anterior pituitary gland, GH is crucial for growth and development. Growth hormone stimulation test - series—Normal anatomy ...
- Asprosin: This fasting-induced hormone regulates hepatic glucose release. Asprosin, a Fasting-Induced Glucogenic Protein Hormone
- Caudamins: A newly discovered subclass of protein hormones showing promise in treating metabolic syndrome and cancer. Caudamins, a new subclass of protein hormones - PMC
Protein Hormones vs. Steroid Hormones:
It's important to note that not all hormones are protein-based. Steroid hormones, such as testosterone and estrogen, are derived from cholesterol. Protein - Hormones, Structure, Function | Britannica
Functions of Protein Hormones:
Protein hormones regulate a wide array of physiological processes, including:
- Metabolism
- Growth and development
- Reproduction
- Immune function
- Homeostasis
The effects of protein hormones are multifaceted and crucial for maintaining the body’s overall health. Physiology, Proteins - StatPearls - NCBI Bookshelf
