Effect of neurotensin on colorectal motor and sensory function in humans.
OBJECTIVE
Animal studies have shown that neurotensin stimulates colonic motility, but little is known on the effect on rectocolonic function in humans. This study was designed to investigate the effect of neurotensin on rectal and colonic motor and sensory function and colonic reflexes in humans.


METHODS
Motor and sensory function of the descending colon and rectum were studied in eight healthy volunteers (5 females; age range, 20-58 years) by using a dual, computerized, rectocolonic, barostat assembly. Measurements were performed during placebo and neurotensin infusion (5 pmol/kg per minute), respectively. Compliance and reflex mechanisms were assessed in both rectum and descending colon. Symptom perception (urge and pain) was scored using Visual Analog Scales (0-10 cm).


RESULTS
Neurotensin significantly (P < 0.05) increased rectal compliance (from 9 +/- 1.1 to 10.1 +/- 1.1 ml/mmHg) and colonic compliance (from 7.9 +/- 0.4 to 9 +/- 0.7 ml/mmHg) during stepwise distensions. Intensity of urge and pain perception during rectal distension was increased by neurotensin (P < 0.05). Sensations during colonic distensions were not altered by neurotensin. For colonic reflexes, during rectal distension the colonic bag volume increased significantly (P < 0.05), whereas during colonic distension rectal bag volume decreased significantly (P < 0.05). Neurotensin delayed the occurrence of these reflexes: they were present at significantly higher pressures compared to placebo (P < 0.05).


CONCLUSIONS
We demonstrated the presence of both a rectocolonic inhibitory and a colorectal stimulatory reflex in healthy volunteers. Neurotensin increases compliance and modulates rectal but not colonic sensitivity. Colorectal and rectocolonic reflexes are impaired during infusion of neurotensin.
van der Veek
Patrick P J
PP
Department of Gastroenterology and Hepatology, Leiden University Medical Centre, Leiden, The Netherlands.
Schots
Elleke D C M
ED
Masclee
Ad A M
AA
D000328:Adult; D003106:Colon / Q000502:physiology*; D005260:Female; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009496:Neurotensin / Q000494:pharmacology*; D017288:Pain Threshold; D010465:Perception; D011312:Pressure; D012007:Rectum / Q000502:physiology*; D012018:Reflex
D009496:Neurotensin