What are peptide hormones?

polypeptide hormones or simply peptide hormones are hormones consisting of amino acids that are secreted by the endocrine system and distributed to the end organs circulating blood. Endocrine organs that eliminate peptide hormones include hypothalamus, pituitary gland, thyroid gland, adrenal glands, ovaries, endocrine pancreas and adipose tissues. Organs that are not traditionally considered to be part of an endocrine system such as heart and gastrointestinal tract can also secrete peptide hormones.

The process of producing these hormones is the same as the process of protein production. The deoxyribonucleoic acid (DNA) of the organism is first translated into ribonucleic acid (MRNA) in the cell, then the MRNA is translated into amino acid chains or precursors of peptide hormones in ribosomes. These amino acid chains, also called pre-hormones, are then sent to an endoplasmic reticulum for removal of signal or front sequences that are about 15 to 30 andMino acids A are located in the n-terminal of the amino acid chain. Signal sequence cleavage results in processed peptides called prohormones. The prohormones are either wrapped in secretory vesicles or are cleaved by enzymes called endopeptidases to form a mature hormone before relaxing into circulation.

Peptide hormones secreted by the hypothalamus are generally called release factors and include a factor of corticotropin-, gonadotropin-, somatotropin- and thyrotropin. Those who secrete the anterior pituitary are hormone stimulating melanocytes, hormone stimulating follicles, luteinizing hormone, adrenocorticotropic hormone (ACTH), thyrotropic hormone and growth hormone or somatotropin. Peptide hormones secreting the rear pituitary are prolactin or mamatrophic hormone, vasopressin or antidiuretic hormone and oxytocin. Ohmezi peptide hormones include thyroxine from the thyroid gland, cortisol of the adrenal glands and inspiresUline from the abdominal.

specific extracellular stimuli induce secretion of polypeptide hormones. For example, when a change in homeostatic balance is changed, they are excreted to restore the balance. The endocrine system usually works by negative and positive feedback or feedback mechanisms with a closed loop. For example, the anterior pituitary secretes ACTH, which stimulates cortisol secretion from the adrenal cortex. When pituitary detects that cortisol levels in the blood are increased, it reduces ACTH production.

For organ stimulation, the peptide hormone in this organ must have a receptor. Peptide hormones receptors are found in the plasma membrane, except for the thyroid hormone receptor, which is located in the nucleus. When the peptide hormone binds to its receptor, the signal transmission and the substances Caldinis LEDs are released to activate specific proteins to increase or inhibit certain substances. The main second messengers include calcium, cyclic adenosine monophosphate (camp),Inositol trihosphate and diacylglycerol (DAG).