Пентагастрин

Описание

Pentagastrin is a synthetic polypeptide and cholecystokinin-2 (CCK₂) receptor agonist. It binds selectively to CCK₂ receptors in guinea pig brain over CCK₁ receptors in rat pancreas (IC₅₀s = 11 and 1,100 nM, respectively). Pentagastrin increases calcium influx and polyphosphoinositide turnover in rat GH3 pituitary cells (EC₅₀s = 23 and 3.9 nM, respectively). It also increases histidine decarboxylase activity in mucous- and endocrine cell-enriched isolated rabbit fundic mucosal cells (EC₅₀ = 2.9 nM). Pentagastrin induces contraction of isolated pig ileum smooth muscle cells in vitro (EC₅₀ = 30 pM). It increases gastric acid and pepsin secretion in conscious cats in vivo (ED₅₀s = 1.29 and 57.3 nmol/kg² per hour, respectively). Formulations containing pentagastrin have previously been used as a diagnostic aid to evaluate gastric acid secretory function.

Химические свойства

A white or almost white powder.

Использование

Pentagastrin is a synthetic polypeptide that has effects like gastrin when given parenterally. It stimulates the secretion of gastric acid, pepsin, and intrinsic factor, and has been used as a diagnostic aid as the pentagastrin-stimulated calcitonin test.

Общее описание

Pentagastrin (Peptavlon), a physiologicalgastric acid secretagogue, is the synthetic pentapeptide derivative:N-t-butyloxycarbonyl-β-alanyl-L-tryptophyl-L-methionyl-L-aspartyl-L-phenylalanyl amide. It contains theCOOH-terminal tetrapeptide amide (H·Try·Met· Asp·Phe·NH₂), which is considered to be the active center ofthe natural gastrins. Accordingly, pentagastrin appears tohave the physiological and pharmacological properties ofthe gastrins, including stimulation of gastric secretion,pepsin secretion, gastric motility, pancreatic secretion ofwater and bicarbonate, pancreatic enzyme secretion, biliaryflow and bicarbonate output, intrinsic factor secretion, andcontraction of the gallbladder.
Pentagastrin is indicated as a diagnostic agent to evaluategastric acid secretory function, and it is useful in testing foranacidity in patients with suspected pernicious anemia, atrophicgastritis or gastric carcinoma, hypersecretion in suspectedduodenal ulcer or postoperative stomal ulcers, andZollinger-Ellison tumor.