Peptihormone

Peptihormone is a term that refers to a peptide hormone. Peptide hormones are a class of hormones that are composed of amino acids linked together by peptide bonds. They are produced by endocrine glands and released into the bloodstream, where they travel to target cells and exert their effects. Examples of peptide hormones include insulin, glucagon, growth hormone, and antidiuretic hormone. These hormones play crucial roles in regulating a wide range of physiological processes, such as metabolism, growth, and water balance. The synthesis of peptide hormones begins with the transcription of a gene into messenger RNA (mRNA). This mRNA is then translated into a precursor protein called a preprohormone. The preprohormone is further processed in the endoplasmic reticulum and Golgi apparatus to remove signal peptides and form a prohormone. Finally, the prohormone is cleaved into the active peptide hormone, which is then packaged into secretory vesicles for release from the cell. The action of peptide hormones is mediated by specific receptors located on the surface of target cells. Upon binding to these receptors, peptide hormones initiate intracellular signaling cascades that ultimately lead to a specific cellular response. The duration of action for peptide hormones is generally short, as they are rapidly degraded by peptidases in the bloodstream and tissues.