Korean J Nephrol.  2002 Mar;21(2):251-258.

Antidiuretic Action of Oxytocin in Normal Men

• Joo KW
• Jeon US
• Oh YK
• Kim GH
• Han JS
• Kim SG
• Lee JS

Abstract

BACKGROUND: The antidiuretic action of oxytocin in human has been controversial. To investigate whether oxytocin directly acts on water balance in human, we evaluated the parameters of urinary concentration in response to administration of oxytocin in ten healthy male volunteers.
METHODS
Oxytocin was infused intravenously at a rate of 20 mU/hour for 2.5 hours and urine was collected during the last 2 hours of oxytocin infusion. Changes in urine volume, urine osmolality, excretions of urine electrolytes and free water clearance after the administrartion of oxytocin were compared with the baseline data.
RESULTS
The changes in the levels of serum electrolytes and osmolality after the administration of oxytocin were not significant compared with the baseline data. The volume of 2 hours' urine were 446+/-75 mL and 289+/-53 mL in the basal state and after the administration of oxytocin, respectively. The urine osmolality was increased significantly by the infusion of oxytocin(427+/-63 mOsm/kg) compared with that in the basal state(223+/-25 mOsm/kg)(p < 0.05). The free water clearance was 110+/-51 mL/2 hours in the basal state and decreased significantly to -57+/-51 mL/2 hours(p < 0.05).
CONCLUSION
We conclude that administration of oxytocin to normal men enhances urinary concentration, evidenced by increased urinary osmolality and decreased free water clearance. In human, oxytocin may play an important role in the regulation of renal water excretion as an antidiuretic hormone.

Keyword

Oxytocin; Antidiuretic; Human

MeSH Terms

Electrolytes
Humans
Male
Osmolar Concentration
Oxytocin*
Volunteers
Water
Electrolytes
Oxytocin
Water