X-RAY-MICROANALYSIS OF MYOMETRIUM IN PARTURIENT WOMEN AT TERM

The purpose of this study was to investigate the elemental composition of myometrial cells from term parturient women with normal and dysfun ctional labour. Myometrial biopsies were obtained from forty-four term pregnant women undergoing Cesarean section. The patients were categor ized according to uterine activity as follows: before labour, normal l abour, labour successfully augmented by oxytocin, oxytocin-resistant l abour, and labour arrested by terbutaline. X-ray microanalysis of free ze-dried sections (16 Fun thick) of the myometrium was carried out. An increase in intracellular phosphorus level (p<.01.) was noted in the normal labour group compared to before labour. In patients with normal labour, higher phosphorus (p<.009) and potassium (p<.005) were found compared to oxytocin resistant labour. Patients with oxytocin resistan t labour had lower intracellular potassium (p<.0006) and phosphorus (p <.02), and higher chloride (p<.05) and sodium (p<.03) compared to leve ls found in patients who responded to oxytocin treatment. In dysfuncti onal (oxytocin-resistant) labour the ion distribution in the myometria l cells might be disturbed. The reduced level of potassium and phospho rus together with the high sodium and chloride levels found in patient s with oxytocin resistant labour may be connected to an impairment in sodium-potassium pump and muscle dysfunction, clinically diagnosed as dystocia.