THE INFLUENCE OF ARGININE-VASOPRESSIN ON STOOL OUTPUT AND GASTROINTESTINAL TRANSIT-TIME IN HEALTHY-VOLUNTEERS

Objective: It was asked whether continuous infusion of arginine-vasopr essin (AVP) could decrease stool output and gastrointestinal transit t ime in healthy volunteers. Design: Randomised single blind cross-over- design. Subjects: 5 healthy male volunteers. Interventions: Continuous s. c. infusion of AVP (7.5 mu g/d) for one week vs. 0.9% NaCl-solutio n (placebo). Some days before the experiment started, the volunteers u nderwent a two-day-thirsting-period (< 500 ml/day). Measurements: AVP- levels in serum, urine output, AVP-urine-excretion, stool frequency, s tool weight, colonic transit time. Results: As compared to saline infu sion both serum-levels of AVP and AVP-excretion in urine were about fo ur times higher during AVP-infusion whereas they were doubled during t hirsting. Accordingly urine output was lower when AVP-levels were high . Parameters of colonic motility did not differ significantly (stool f requency 6.8 +/- 0.8/week for placebo vs. 6.8 +/- 0.5/week during AVP stool weight 200.3 +/- 25.0 g/d vs. 210.6 +/- 21.1 g/d, total colonic transit 22.9 +/- 7.0 hours vs. 25.7 +/- 5.8 hours). Conclusion: 1. AVP is well absorbed when applied subcutaneously. 2. AVP in the dosage gi ven has no major influence on stool output and gastrointestinal transi t time in healthy volunteers.