RELATIONSHIP BETWEEN INTERDIGESTIVE MOTILITY AND SECRETION OF IMMUNOGLOBULIN-A IN HUMAN PROXIMAL SMALL-INTESTINE

In 17 healthy volunteers, we studied the dynamics of secretory immunog lobulin A (SIgA) release in the proximal small intestine (distal duode num and proximal jejunum), using a modified triple-lumen perfusion tec hnique. Secretory data were related to the current phase of the migrat ing motor complex (MMC), as recorded by manometry. In both segments, l uminal SIgA output changed cyclically, with peak outputs occurring at the end of the MMC cycle (late phase II), These MMC-related changes we re due to two factors: cyclic inflow of SIgA from more proximal sites, and a cyclic release of SIgA from the test segment that correlated in time with an increase in epithelial fluid secretion. Cyclic intestina l SIgA release may thus be another secretory component of the MMC. The data are compatible with the hypothesis that motility and SIgA releas e are linked by motility-activated chloride secretion from the intesti nal crypts.