製品名 : 酢酸オルニプレシン
同義語:8-オルニチン-バソプレシン
CAS#: 3397-23-7; 914453-98-8
分子式: C45H63N13○12S2
MW: 1042.19
順序: H-Cys-Tyr-Phe-Gln-Asn-Cys-Pro-Orn-Gly-NH2 (ジスルフィド結合)
外観: 白い粉
純度 (HPLC):≧98.0%
単一の不純物 (HPLC): ≤2.0%
アセテート含有量(HPLC): 5.0%-12.0%
水分含有量 (カール・フィッシャー): ≤10.0%
ペプチド含有量: ≧80.0%
オルニプレシンはバソプレシンの合成誘導体です (アルギニン-8-バソプレシン) オルニチンがアルギニンの代わりに使用されます。 8 位置. 位置のアミノ酸残基の塩基性 8 バソプレシン分子の昇圧作用と抗利尿作用が決まります. オルニチン, 塩基性が低く、短鎖アミノ酸である, reduces the binding of ornipressin to the receptors in the distal tubule of the nephron without impairing its binding to the receptors in the vascular smooth muscle which mediate vasoconstriction. したがって, ornipressin has minimal antidiuretic activity whilst maintaining equipotent vasoconstrictor activity as the natural hormone, vasopressin.
Ornipressin, which has a high affinity for V1あ 受容体 , activates Gs proteins, which stimulate phospholipase C and result in a breakdown of membrane lipids to inositol triphosphate (IP3) and diacylglycerol (DAG); IP3 releases calcium from the endoplasmic reticulum, thus increasing cytosolic calcium, while DAG activates protein kinase C which phosphorylates cellular proteins. This cascade of biochemical reactions leads to sustained vasoconstriction. しかし, at high concentrations (>0.1 IU mL−1), ornipressin binds to the V2 receptors when the V1あ receptors are fully saturated. Activation of V2 receptors results in an increase in cyclic AMP which leads to vasodilatation, a paradoxical effect demonstrated by Fruhstorfer and Heisler.
