Haemodynamic changes in the small intestine correlate to migrating motor complex in humans.
OBJECTIVE
To evaluate local intestinal blood flow and its relationship to fasting gut motility in humans.


METHODS
Regional laser Doppler flowmetry (LDF) was carried out for 8 h in 14 tasted volunteers. LDF measured as perfusion units (PU) was performed using two single-fibre microprobes attached to a small intestinal manometry tube, which monitored migrating motor complexes (MMCs). Luminal pressures of small intestine were registered in analogue and digital recordings.


RESULTS
During phase 1 of MMC, PU values of 65 (33-95) and 37 (20-100) in proximal and distal duodenum were measured. During phase 2, PU values increased by 17% and 38%, respectively (each P < 0.001). At phase 3 of MMC, corresponding PU values increased by 363% and 443% (each P < 0.001) and remained at high levels until termination of phase 3. During phase 3 there was aboral propagation of LDF activity. Computerized recordings allowed detailed analysis of relationships between LDF pattern and luminal pressures. At pressures below 48 (42-54) mmHg, individual LDF cycles and contraction cycles were phase displaced at 180 degrees, indicating low perfusion during contractions. When pressures exceeded 48 (42-54) mmHg, a decrease in PU was registered and the cycling pattern of LDF was abolished. Then, as luminal pressure decreased below 33 (25-41) mmHg, PU increased by 246%.


CONCLUSIONS
Our findings show a relationship between fasting motility and blood flow in the human gut, in which the blood flow exhibited a pattern similar to phase 1, 2 and 3 of the MMC.
Thollander
M
M
Department of Medicine, Karolinska Hospital, Stockholm, Sweden.
Hellström
P M
PM
Svensson
T H
TH
Gazelius
B
B
D000328:Adult; D005769:Gastrointestinal Motility; D006439:Hemodynamics; D006801:Humans; D007421:Intestine, Small / Q000098:blood supply*; D017078:Laser-Doppler Flowmetry; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D016065:Myoelectric Complex, Migrating / Q000502:physiology*; D010477:Perfusion; D011312:Pressure