Atrial natriuretic factor and renal sodium excretion during ventilation with PEEP in hypervolemic dogs.
Controlled mandatory ventilation with positive end-expiratory pressure (PEEP) reduces renal sodium excretion. To examine whether atrial natriuretic factor (ANF) is involved in the renal response to alterations in end-expiratory pressure in hypervolemic dogs, experiments were performed on anesthetized dogs with increased blood volume. Changing from PEEP to zero end-expiratory pressure (ZEEP) increased sodium excretion by 145 +/- 61 from 310 +/- 61 mumol/min and increased plasma immunoreactive (ir) ANF by 104 +/- 27 from 136 +/- 21 pg/ml. Changing from ZEEP to PEEP reduced sodium excretion by 136 +/- 36 mumol/min and reduced plasma irANF by 98 +/- 22 pg/ml. To examine a possible causal relationship, ANF (6 ng.min-1.kg body wt-1) was infused intravenously during PEEP to raise plasma irANF to the same level as during ZEEP. Sodium excretion increased by 80 +/- 36 from 290 +/- 78 mumol/min as plasma irANF increased by 96 +/- 28 from 148 +/- 28 pg/ml. We conclude that alterations in end-expiratory pressure lead to great changes in plasma irANF and sodium excretion in dogs with increased blood volume. Comparison of the effects of altering end-expiratory pressure and infusing ANF indicates that a substantial part of the changes in sodium excretion during variations in end-expiratory pressure can be attributed to changes in plasma irANF.
Christensen
G
G
Institute for Experimental Medical Research, University of Oslo, Ullevaal Hospital, Norway.
Bugge
J F
JF
Ostensen
J
J
Kiil
F
F
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood* / Q000378:metabolism; D001810:Blood Volume / Q000502:physiology*; D004285:Dogs; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D007668:Kidney / Q000502:physiology; D008297:Male; D009318:Natriuresis / Q000502:physiology*; D011175:Positive-Pressure Respiration / Q000009:adverse effects; D012083:Renin / Q000097:blood
D009320:Atrial Natriuretic Factor; D012083:Renin