The influence of arginine-vasopressin on stool output and gastrointestinal transit time in healthy volunteers

Abstract

Objective: It was asked whether continuous infusion of arginine-vasopressin (AVP) could decrease stool output and gastrointestinal transit time in healthy volunteers.

Design: Randomised single blind cross-over-design.

Subjects: 5 healthy male volunteers.

Interventions: Continuous s.c. infusion of AVP (7.5 micrograms/d) for one week vs. 0.9% NaCl-solution (placebo). Some days before the experiment started, the volunteers underwent a two-day-thirsting-period (< 500 ml/day).

Measurements: AVP-levels in serum, urine output, AVP-urine-excretion, stool frequency, stool weight, colonic transit time.

Results: As compared to saline infusion both serum-levels of AVP and AVP-excretion in urine were about four times higher during AVP-infusion whereas they were doubled during thirsting. Accordingly urine output was lower when AVP-levels were high. Parameters of colonic motility did not differ significantly (stool frequency 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 gld, 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 given has no major influence on stool output and gastrointestinal transit time in healthy volunteers.