title: Amniotic fluid ionic concentration in response to chronic fetal vasopressin infusion.
abstract: Chronically prepared, third trimester fetal lambs were administered 72-h intravenous infusions of arginine vasopressin (AVP) (65 or 130 mU/kg h) or 0.9% saline. Saline infusion preceding the AVP infusion did not change amniotic fluid (AF) composition. During the AVP infusion, there were significant increases in amniotic fluid osmolality (278.8 +/- 4.9 to 302.1 +/- 4.5 mosm) and in sodium (122.7 +/- 3.3 to 135.3 +/- 3.6 meq/l) and potassium (9.7 +/- 2.6 to 13.8 +/- 1.3 meq/l) concentrations. Saline infusion after the AVP infusion resulted in return of AF osmolality, sodium, and potassium toward normal levels. Fetal plasma and amniotic fluid AVP levels measured by radioimmunoassay significantly increased during AVP infusion and decreased during the subsequent saline infusion. There were no changes in maternal or fetal plasma osmolality in response to AVP. These results suggest that fetal AVP released in response to intrauterine stress may alter the composition and osmolality of amniotic fluid in a reversible manner.
mesh_terms: D000653:Amniotic Fluid / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D001127:Arginine Vasopressin / Q000008:administration & dosage / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D005312:Fetal Blood / Q000032:analysis; D005333:Fetus / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects; D007263:Infusions, Parenteral; D009994:Osmolar Concentration; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D011188:Potassium / Q000378:metabolism; D011247:Pregnancy; D012756:Sheep; D012964:Sodium / Q000378:metabolism
chemical_list: D001127:Arginine Vasopressin; D002245:Carbon Dioxide; D012964:Sodium; D011188:Potassium; D010100:Oxygen