Protein hormones, also known as polypeptide hormones, are crucial signaling molecules in the body. Many vital bodily functions rely on these hormones for regulation and control. Let's explore some key examples:
Key Examples of Protein Hormones
- Insulin: Produced by the pancreas, insulin regulates blood sugar levels. It facilitates glucose uptake by cells, preventing hyperglycemia.
- Glucagon: Also from the pancreas, glucagon works opposite to insulin. It raises blood glucose levels when they fall too low.
- Thyrocalcitonin (Calcitonin): Secreted by the thyroid gland, calcitonin helps regulate calcium levels in the blood, primarily by reducing blood calcium.
- Pituitary Hormones: The pituitary gland produces a variety of protein hormones, including:
- Growth Hormone (GH): Stimulates growth and cell reproduction.
- Follicle-Stimulating Hormone (FSH): Plays a critical role in reproductive function in both males and females.
- Prolactin (PRL): Essential for milk production in lactating females.
- Hypothalamic Hormones: The hypothalamus releases several protein hormones that regulate the pituitary gland's activity. Examples include Gonadotropin-releasing hormone (GnRH) and Corticotropin-releasing hormone (CRH).
- Insulin-like Growth Factor-1 (IGF-1): This hormone plays a key role in childhood growth and continues to have metabolic effects in adulthood.
Further Examples and Considerations
As highlighted in research like the article "Protein Hormones and Immunity" (https://pmc.ncbi.nlm.nih.gov/articles/PMC1894894/), prolactin (PRL), growth hormone (GH), and IGF-1 demonstrate the significant roles protein hormones play in immunity. It's important to note that some hormones, while not strictly proteins, are peptides – short chains of amino acids – and function similarly. Examples include many of the hypothalamic and pituitary hormones.
