A THE name implies, angiotonin is characterized by its action on vascular smooth muscle. This activity is usually assayed from its pressor effect in intact animals. Preparations of angiotonin have also been observed to cause contraction of nonvascular smooth muscle and, on this basis, the pressor activity of angiotonin has been attributed to a direct myotropic action of a single substance' ; th...

Local anaesthetics as a group possess spasmolytic effect on the smooth muscles (2). Uterine muscle though basically a smooth muscle organ, differs from other smooth muscle organs in many respects. Physiologically it is more under the control of sex hormones than the autonomic nervous system. There exists wide species variation in the responses to autonomic nervous stimulation. Pharmacologically...

This paper describes the synthesis and biological activity of [5-L-asparagine-alpha,beta,beta-d(3)]-deamino-oxytocin. The model peptide S-benzyl-beta-mercaptopropionyl-L- asparaginyl-alpha,beta,beta-d(3)-glycinamide was also prepared to observe the effect of the conditions of peptide synthesis on the deuterium content. It was found that normal synthetic procedures could be used without a signif...

The administration of oxytocic drugs during caesarean section is an important intervention to prevent uterine atony or treat established postpartum haemorrhage. Considerable past and current research has shown that these agents have a narrow therapeutic range. A detailed knowledge by anaesthetists of optimal doses and side effects is therefore required. Oxytocin remains the first line agent. In...

A 29-year-old woman sustained an acute massive pulmonary embolism in the 32nd week of pregnancy. Rapid clinical improvement followed the use of streptokinase. Treatment was continued for 41 hours, including labour and the first three hours after delivery. There was slow but severe postpartum haemorrhage. Partial uterine atony occurred, and may have been due, at least in part, to fibrin degradat...

Plasma oxytocin levels were measured serially in 22 women receiving prostaglandin E(2) or F(2alpha) intravenously for the induction of labour. Oxytocin was detected in the plasma of 19 of the 22 women; positive levels were found in 60 (43%) of 139 plasma samples, an incidence similar to that in the late first stage of spontaneous labour. Oxytocin was found in the maternal plasma even when the f...