Gender influence on jejunal migrating motor complex

The role of gender and the menstrual cycle in small bowel motility has not been clearly elucidated. Jejunal motility was recorded with a nasojejunal c atheter incorporating five solid-state pressure transducers in ambulatory m enstruating women and men of comparable age over 24 h. All women were studi ed twice, in the early follicular (early-F) and midluteal (mid-L) phases of the menstrual cycle, verified by determining serum levels of gonadal stero ids and gonadotropins. The propagation velocity of phase III was slow and t he contraction amplitude was high in both menstrual cycle phases compared w ith men, and these parameters were correlated with serum estrogen levels in the mid-L phase. In the early-F phase, migrating motor complex (MMC) cycle duration during sleep was long compared with other groups and positively c orrelated with estrogen concentrations, whereas in the mid-L phase MMC cycl e duration during sleep was negatively correlated with serum progesterone l evels. In all groups, the frequency of phase III contractions was low and t he intercontractile interval measured from pressure peak to peak was long d uring sleep compared with the awake state. Postprandial motility did not di splay gender difference in any parameter examined. The results demonstrate that the majority of patterns of motility are similar in menstruating women and men, whereas certain aspects of the MMC, most conspicuously propagatio n velocity and phase III contraction amplitude, differ. We have also docume nted circadian variation of phase III contraction frequency in both women a nd men.