Effects of nonhypotensive hemorrhage on renal organ and urinary clearances of vasopressin in the dog.
A study was undertaken to investigate the effects of moderate nonhypotensive hemorrhage on the renal organ and urinary clearances of vasopressin in anesthetized dogs. A nonhypotensive hemorrhage was conducted in nine dogs by withdrawal of 12 ml/kg arterial blood over 10 min. This reduction in blood volume increased the plasma vasopressin concentration from a prehemorrhage value of 4.3 +/- 0.5 to 12.5 +/- 3.4 microU/ml (P less than 0.01) in the 15-min period immediately after hemorrhage and to 8.1 +/- 1.4 microU/ml (P less than 0.01) in the 45- to 60-min period after hemorrhage. The increased plasma vasopressin concentration was not associated with changes in either plasma osmolality or mean arterial blood pressure. The urinary excretion of vasopressin increased significantly after hemorrhage (P less than 0.01, 0-15 min after hemorrhage; P less than 0.05, 45-60 min after hemorrhage) and correlated significantly with the plasma vasopressin concentration (r = 0.92; P less than 0.001). However, this moderate nonhypotensive hemorrhage did not change the renal vasopressin extraction ratio or the renal organ and urinary clearances of vasopressin from their prehemorrhage values of 0.27 +/- 0.02, 2.00 +/- 0.20 ml/min X kg, and 1.43 +/- 0.13 ml/min X kg, respectively. At no time were these values different from those in nine time control dogs. Thus, changes in the renal handling of vasopressin do not contribute to the increase in the plasma vasopressin concentration after moderate nonhypotensive hemorrhage.
D000818:Animals; D001794:Blood Pressure; D001810:Blood Volume; D004285:Dogs; D006470:Hemorrhage / Q000503:physiopathology*; D008297:Male; D009994:Osmolar Concentration; D012079:Renal Circulation; D014667:Vasopressins / Q000378:metabolism* / Q000652:urine
D014667:Vasopressins