Endocrinology/Hormones

<p>This 32 amino acid peptide contains a 17 amino acid ring structure that is common to all natriuretic peptides. It is also called the brain natriuretic peptide (BNP) because it was first identified in porcine brain- however, the main source of this peptide is not the brain but the cardiac ventricle. This cardiac neurohormone is secreted from the ventricles in response to volume expansion and pressure overload. It has natriuretic and vasodilatory effects and suppresses the renin-angiotensin-aldosterone system.</p>

<p>Mammalian bombesin-like peptide neurotransmitter that is an agonist for the gastrin-releasing peptide receptor (GRPR). It exhibits physiological functions such as gastrin and somatostatin release and chemoattraction within the immune system.</p>

<p>Pro B-type natriuretic peptide (Pro-BNP) is secreted from cardiac myocytes and cleaved into BNP and the remaining part of the prohormone N-terminal proBNP (NT-proBNP). When the heart fibres become stretched more BNP and NT-proBNP are released to try and compensate for the increased pressure. During heart failure the walls of the atria become over stretched and thus increase the levels of NT-proBNP detectable. NT-proBNP has a longer half-life than BNP and therefore is detectable at higher levels in blood plasma than BNP. NT-pro-BNP is believed to be cleared by renal excretion, but this is not confirmed. As a diagnostic tool, NT-proBNP (47-76) has become very useful in helping diagnose heart failure and provide a prognosis. The measurement of NT-proBNP (47-76) has been incorporated into management and guidelines of clinical settings. As a research tool it still provides valuable data such as symptoms onset in relation to NT-proBNP levels and how inflammation effects the level of BNP as well as the BNP/ NT-proBNP ratio.</p>

<p>Vasopressin is a peptide antidiuretic hormone, originating from the hypothalamus, that regulates water balance in the body. It is also known as arginine vasopressin or antidiuretic hormone (ADH). The clinical efficacy of vasopressin has been evaluated using in vitro methods on mouse monoclonal antibody production cells, blood sampling, and microdialysis probes for monitoring blood pressure. This product is available in the salt form: Acetate.</p>

<p>GPS1573 is a potent and dose-dependent peptide antagonist of adrenocorticotrophic (ACTH) -stimulated melanocortin type 2 receptor (MC2R). Along with GPS1574, GPS1773 is an ACTH analogue and as such antagonises MC2R in the nanomolar range.The clinical relevance of GPS1573 is related to Cushing's disease and syndrome, which are both associated with a hypercortisolemic state. Selective antagonism of MC2R using GPS1573 may be a novel treatment modality for Cushing's disease and syndrome.</p>

<p>Peptide derived from the gastrointestinal hormone Motilin, secreted from endocrine cells in the small intestines, mainly from the jejunum and duodenum, in response to the fasting, drinking water or the mechanical stimulus of eating.</p>

<p>Glucagon-like peptide (GLP) 1 is a post-translationally modified version of proglucagon. GLP-1 (1-37) is a naturally produced analog of GLP-1. Unlike truncated GLP-1, GLP-1 (1-37) does not alter food intake in rat models or pancreatic insulin secretion. GLP-1 (1-37) can induce insulin production in developing adult intestinal cells via upregulation of the ngn3 gene and its downstream targets. This can restore glucose homeostasis when implanted into diabetic mice. GLP-1 (1-37) may offer a  future treatment for diabetes mellitus. GLP-1 (1-37) can also inhibit chemokine-induced migration of human CD4-positive lymphocytes, an early step in atherogenesis. This raises the possibility that GLP-1 (1-37) is part of a novel mechanism to modulate vascular disease.</p>

<p>Insulin is a polypeptide composed of two peptide chains referred to as the alpha chain and β chain. These chains are linked by two disulphide bonds, and an additional disulphide is formed within the alpha chain. In most species, the alpha chain consists of 21 amino acids and the β chain of 30 amino acids. Insulin is normally secreted rapidly from the β-cells of the pancreatic islets in response to nutrients absorbed after a meal. In type 1 diabetes mellitus, there may be an absolute insulin deficiency as a consequence of autoimmune destruction of the β-cells. On the other hand, in type 2 diabetes mellitus, insulin secretion is impaired and is inadequate to overcome peripheral insulin resistance.</p>

<p>Calcitonin is a peptide hormone excreted by the thyroid parafollicular cells to regulate calcium and phosphorus levels. Calcitonin acts in opposition to parathyroid hormone (PTH) and vitamin D. Calcitonin functions by inhibiting osteoclast activity in the bones preventing calcium release- there is also inhibition of renal tubular cell reabsorption of calcium and phosphate, so they are excreted preventing a rise in levels.Calcitonin is used for as marker for detection and prognosis of nodular thyroid diseases. Medullary thyroid cancer is one example of the malignant parafollicular cells detectable with the assay, as they present with an increased calcitonin level even at an early stage.Since the discovery of calcitonin over 50 years ago the salmon sourced peptide has been used in numerous treatments including bone metastases, Paget disease, hypercalcaemia, and postmenopausal osteoporosis. The salmon calcitonin has been shown to be equivalent to human form but more active and can be synthetically generated.</p>

<p>This is a truncated exendin-4 peptide, the original peptide was identified in Gila monster lizard (Heloderma suspectum). Exendin-4 is an incretin mimetic, an analog of glucagon-like-peptide-1 (GLP-1), it stimulates insulin secretion and modulates gastric emptying to slow the entry of ingested sugars into the bloodstream. Exendin-4 is resistant to cleavage by plasma DPP-IV unlike GLP-1. This gives it a longer half-life and duration of action than GLP-1, as well as greater potency in vivo. Exendin-4 increases insulin sensitivity and improves glucose tolerance and is currently used for the treatment of Type 2 diabetes mellitus in its synthetic form Exenatide.Exendin-4 also promotes the production and proliferation of β-cells leading to regeneration of the pancreas. It is a ligand to the exendin receptor and increases pancreatic acinar cell cAMP levels. However, the GLP-1 analog was found to have a toxic effect by inducing hypotension due to relaxation of the cardiac smooth muscle.</p>

<p>ANP (1-23) is derived from the atrial natriuretic peptide (ANP) which is a cardiac hormone involved in maintaining cardio-renal homeostasis. This occurs through the activation of the guanylyl cyclase-coupled receptor, resulting in the increased concentration of cyclic guanylate monophosphate. Moreover its function in the processes of anti-proliferation and anti-angiogenesis allow it to take part in cardiovascular remodelling.ANP is a member of the natriuretic peptide family and it is encoded by the NPPA gene, located on chromosome 1. Once synthesized from the 151 amino acid pre-prohormone into its biologically active form, ANP is secreted by the atrial cardiomyocytes in the circulating forms: ANP (1-98) and ANP (99-126). This synthesis process involves the signal peptide being removed from the pre-prohormone resulting in pro-ANP (1-126) which is converted into the circulating forms by the type II transmembrane serine protease Corin.</p>

<p>Gastric inhibitory polypeptide (GIP) is an inhibiting hormone of the secretin family of hormones. While GIP is a weak inhibitor of gastric acid secretion, its main role is to stimulate insulin secretion - in a glucose-dependent mechanism. Therefore, GIP is referred to as a glucose-dependent insulinotropic peptide. In GIP (Pro 3) the glutamic acid at position 3 has been substituted for a proline.GIP is derived from a 153-amino acid proprotein encoded by the GIP gene and circulates as a biologically active 42-amino acid peptide. It is synthesised by K cells, which are found in the mucosa of the duodenum and the jejunum of the gastrointestinal tract. GIP receptors are seven-transmembrane proteins found on β-cells in the pancreas. These β-cells are those that are able to simultaneously detect glucose and release insulin as a result to GIP binding.The clinical relevance of GIP is related to type 2 diabetes mellitus (T2DM)- studies have found that T2DM diabetics are unresponsive to GIP and have lower levels of GIP secretion after a meal when compared to non-diabetics. In research involving knockout mice, it was found that absence of the GIP receptors correlates with resistance to obesity.</p>

<p>ANP (9-22) is derived from the atrial natriuretic peptide (ANP) which is a cardiac hormone involved in maintaining cardio-renal homeostasis. This occurs through the activation of the guanylyl cyclase-coupled receptor, resulting in the increased concentration of cyclic guanylate monophosphate. Moreover its function in the processes of anti-proliferation and anti-angiogenesis allow it to take part in the cardiovascular remodelling process.ANP is a member of the natriuretic peptide family and it is encoded by the NPPA gene, located on chromosome 1. Once synthesized from the 151 amino acid pre-prohormone into its biologically active form, ANP is secreted by the atrial cardiomyocytes in the circulating forms: ANP (1-98) and ANP (99-126). This synthesis process involves the signal peptide being removed from the pre-prohormone resulting in proANP (1-126) which is converted into the circulating forms by the type II transmembrane serine protease Corin.</p>

<p>C- terminal fragment of adrenocorticotropic hormone (ACTH) also known as corticotropin, and competitive antagonist of ACTH receptor (ACTHR), also known as melanocortin type 2 receptor (MC2R).ACTH is a member of the melanocortins-peptide family, this tropic hormone is produced and secreted by the anterior pituitary gland. ACTH is an important component of the hypothalamic-pituitary-adrenal (HPA) axis and is often produced in response to biological stress. ACTH acts to increase the production and release of cortisol via its interaction with ACTHR. Receptor activation increases the intracellular concentration of cAMP via adenylyl cyclase. Abnormal ACTH levels in the body have been linked to primary adrenal insufficiency/Addison's disease, Cushing's disease and secondary adrenal insufficiency.</p>

<p>This is an incretin hormone that causes glucose dependent release of insulin by pancreatic beta cells. It is the cleavage product of GLP-1 (1-36) amide peptide.  This peptide, human GLP-1 (7–36), shares the same sequence with preproglucagon (78-107), amide, human.</p>

<p>ANP (13-26) is derived from the atrial natriuretic peptide (ANP) which is a cardiac hormone involved in maintaining cardio-renal homeostasis. This occurs through the activation of the guanylyl cyclase-coupled receptor, resulting in the increased concentration of cyclic guanylate monophosphate. Moreover its function in the processes of anti-proliferation and anti-angiogenesis allow it to take part in the cardiovascular remodelling process.ANP is a member of the natriuretic peptide family and it is encoded by the NPPA gene, located on chromosome 1. Once synthesized from the 151 amino acid pre-prohormone into its biologically active form, ANP is secreted by the atrial cardiomyocytes in the circulating forms: ANP (1-98) and ANP (99-126). This synthesis process involves the signal peptide being removed from the pre-prohormone resulting in proANP (1-126) which is converted into the circulating forms by the type II transmembrane serine protease Corin.</p>

<p>ANP (7-23) is derived from the atrial natriuretic peptide (ANP) which is a cardiac hormone involved in maintaining cardio-renal homeostasis. This occurs through the activation of the guanylyl cyclase-coupled receptor, resulting in the increased concentration of cyclic guanylate monophosphate. Moreover its function in the processes of anti-proliferation and anti-angiogenesis allow it to take part in the cardiovascular remodelling process.ANP is a member of the natriuretic peptide family and it is encoded by the NPPA gene, located on chromosome 1. Once synthesized from the 151 amino acid pre-prohormone into its biologically active form, ANP is secreted by the atrial cardiomyocytes in the circulating forms: ANP (1-98) and ANP (99-126). This synthesis process involves the signal peptide being removed from the pre-prohormone resulting in proANP (1-126) which is converted into the circulating forms by the type II transmembrane serine protease Corin.</p>

<p>N-terminal tryptic peptide of parathyroid hormone (PTH), used for quantification and optimisation in LC-MS/MS assays.PTH is an 84-amino-acid polypeptide hormone (PTH 1-84) which is secreted by the parathyroid glands along with its fragments (such as PTH 1-34 and PTH 7-84). PTH increases calcium and decrease phosphate levels in the blood and the abundance of PTH-derived peptides is regulated by blood calcium levels. PTH inhibits the bone growth-promoting activity of osteoblasts and induces osteoclasts to resorb bone and release calcium and phosphate ions into the blood. PTH binds to and activates the receptor parathyroid hormone receptor 1 (PTHR1). PTHR1 is a G-protein-coupled receptor (GPCR) which regulates mineral ion homeostasis, bone turnover and skeletal development</p>

ANP (7-20) is derived from the atrial natriuretic peptide (ANP) which is a cardiac hormone involved in maintaining cardio-renal homeostasis. This occurs through the activation of the guanylyl cyclase-coupled receptor, resulting in the increased concentration of cyclic guanylate monophosphate. Moreover its function in the processes of anti-proliferation and anti-angiogenesis allow it to take part in the cardiovascular remodelling process.ANP is a member of the natriuretic peptide family and it is encoded by the NPPA gene, located on chromosome 1. Once synthesized from the 151 amino acid pre-prohormone into its biologically active form, ANP is secreted by the atrial cardiomyocytes in the circulating forms: ANP (1-98) and ANP (99-126). This synthesis process involves the signal peptide being removed from the pre-prohormone resulting in proANP (1-126) which is converted into the circulating forms by the type II transmembrane serine protease Corin.

Bradykinins and their associated kinins are inflammatory mediators produced during inflammation. The two main kinins in mammals are the nonapeptide bradykinin, BK (1-9) and the decapeptide kallidin (KD), [Lys0]-BK(1-10). Their biological actions are mediated by two distinct receptors, termed B1 and B2.-BK is involved in several pathophysiological processes, such as inflammation, pain, cell proliferation, and tumours. It plays a crucial role in corneal epithelial cells, corneal stromal cells, and fibroblasts.Inflammation has been reported as one significant hallmark of breast cancer in relation to tumour development, metastasis, and invasion. The bradykinin receptor 1 (B1R) associated with kallidin is highly expressed on inflammatory breast tumour cells thus providing a promising targeting site for tumour recognition and sufficient receptor mediated endocytosis.