Study of the intramural oviduct response to tubal and uterine distension: identification of tubo-uterine sphincter and reflex.
The effect of tubal and uterine distension on the intramural portion of the oviduct (IMO) was studied in 11 women (mean age 31.1 years). The IMO length was determined and the pressure response of the IMO to distension of the anaesthetized oviduct and uterus was examined. A 1.2 cm long high pressure zone (32.2 +/- 6.9 cm H2O) was identified in the IMO. An IMO pressure drop occurred upon oviduct distension with 2 ml of CO2 (P < 0.01); distension with greater volumes induced the same pressure drop (not significant). The IMO pressure increased with 10 ml uterine distension (P < 0.05); distension with greater volumes did not induce further pressure rises (not significant). Distension of each of the anaesthetized oviduct, uterus and IMO separately effected no IMO pressure response. A 'tubo-uterine' physiological sphincter is postulated at the high pressure zone of the IMO. It relaxes or contracts upon tubal or uterine distension respectively. The sphincter response to tubal or uterine distension is suggested to occur by a reflex action through a 'tubo-uterine' reflex, as shown by reproducible results and sphincteric non-response upon anaesthetization of the two arms of the reflex.
Shafik
A
A
Department of Surgery and Experimental Research, Faculty of Medicine, Cairo University, Egypt.
D000328:Adult; D001696:Biomechanical Phenomena; D002404:Catheterization; D005187:Fallopian Tubes / Q000502:physiology*; D005260:Female; D006801:Humans; D011312:Pressure; D012018:Reflex / Q000502:physiology*; D014599:Uterus / Q000502:physiology*