Lack of effect of an inspiratory threshold load on plasma atrial natriuretic peptide levels
Warley ARH., Fontes F., Wilson M., Raine AEG., Stradling JR.
<jats:p>1. After a run-in period, six healthy, recumbent, water-loaded male subjects breathed through an inspiratory threshold load for 90 min. To correct for prolonged recumbency, a similar protocol was followed on a separate control day, but without an inspiratory load.</jats:p> <jats:p>2. A negative intrathoracic pressure of at least 30 cmH2O was required to overcome the threshold load.</jats:p> <jats:p>3. Urine was collected every 30 min and analysed for sodium concentration.</jats:p> <jats:p>4. Plasma samples were collected every 30 min and analysed for atrial natriuretic peptide concentration.</jats:p> <jats:p>5. The inspiratory load had no effect on urine volume, urinary sodium excretion or plasma atrial natriuretic peptide levels.</jats:p>