CLINICAL PHARMACOLOGY Uterine motility depends on the formation of the contractile protein actomyosin under the influence of the Ca dependent phosphorylating enzyme myosin light-chain kinase. Oxytocin promotes contractions
ثبت نشده
چکیده
Pitocin (oxytocin injection, USP) is a sterile, clear, colorless aqueous solution of synthetic oxytocin, for intravenous infusion or intramuscular injection. Pitocin is a nonapeptide found in pituitary extracts from mammals. It is standardized to contain 10 units of oxytocic hormone/mL and contains 0.5% Chlorobutanol, a chloroform derivative as a preservative, with the pH adjusted with acetic acid. Pitocin may contain up to 16% of total impurities. The hormone is prepared synthetically to avoid possible contamination with vasopressin (ADH) and other small polypeptides with biologic activity. Pitocin has the empirical formula C43H66N12O12S2 (molecular weight 1007.19). The structural formula is as follows:
منابع مشابه
Pennogenin Tetraglycoside Induces Rat Myometrial Contraction and MLC20 Phosphorylation via PLC-IP3 and RhoA/Rho Kinase Signaling Pathways
BACKGROUND Total steroidal saponins extracted from the rhizome of Paris polyphylla Sm. var. yunnanensis (TSSPs) have been widely used in China for the treatment of abnormal uterine bleeding. We previously studied the main active constituents of TSSPs and their structure-activity relationships with respect to rat myometrial contractions. Tg (pennogenin tetraglycoside) was identified as one of th...
متن کاملOxytocin and parturition: a role for increased myometrial calcium and calcium sensitization?
Preterm birth is associated with the majority of all death and chronic disability related to pregnancy, birth and the neonatal period. The costs to families and to the health care system are enormous. Current approaches to prevent or arrest preterm labour have been unsuccessful. This failure is largely based on our poor understanding of the regulation of the timing and maintenance of parturitio...
متن کاملRhoA/Rho-kinase cascade is involved in oxytocin-induced rat uterine contraction.
The RhoA/Rho-kinase cascade is involved in various cellular functions, including migration, proliferation, and smooth muscle contraction. We examined the potential role of this pathway in oxytocin-induced uterine contraction. The specific Rho-kinase inhibitor Y-27632 inhibited oxytocin-induced rat uterine contraction on d 21 of pregnancy in a concentration-dependent manner, whereas the extent o...
متن کاملBrief Review Regulation of Contraction and Relaxation in Arterial Smooth Muscle
Intracellular calcium concentration ([Ca]i)-dependent activation of myosin light chain kinase and its phosphorylation of the 20-kd light chain of myosin is generally considered the primary mechanism responsible for regulation of contractile force in arterial smooth muscle. However, recent data suggest that the relation between [Ca], and myosin light chain phosphorylation is variable and depends...
متن کاملGlioma migration can be blocked by nontoxic inhibitors of myosin II.
Anaplastic gliomas are infiltrative tumors, and their ability to migrate through normal brain contributes to their highly malignant behavior. Invasion of brain requires cell motility, which in turn depends on the activity of the cytoskeleton. A cytoskeletal component central to this process is myosin II, the cytoplasmic analogue of smooth and skeletal muscle myosin. Myosin II activity is regula...
متن کامل