Atrial peptide natriuresis in the rat without genuine rise in filtration rate or wash-out of medullary electrolytes.
1. Effects of synthetic atrial natriuretic peptide ( ANP) on renal excretion, total renal blood flow (RBF), glomerular filtration rate (GFR) and tissue electrical admittance (reciprocal impedance, an estimate of tissue electrolytes) were determined in pentobarbitone-anaesthetized rats. GFR was measured both as inulin clearance (Cin) and as a product of renal plasma flow (RPF) and inulin extraction ratio (Ein). 2. With the lowest dose of ANP (0.35 micrograms/(kg min) I.V.) a 5-fold increase in sodium excretion occurred without measurable change in Cin, RPF x Ein nor medullary electrolyte concentration estimated from tissue electrical admittance. 3. With medium and high dosage (2 and 6 micrograms/(kg min), respectively), major and rapid increases in sodium excretion and urine flow were associated with an acute increase in Cin but not RPF x Ein. 4. The RBF increase observed in all groups of rats was not dose-related and did not parallel the natriuresis. Electrolyte concentration in the medullary tissue showed a modest transient decrease in rats given medium and high ANP doses. 5. We conclude that pronounced ANP natriuresis can develop in the absence of a measurable increase of GFR, estimated by a method not subject to urinary dead space error (RPF x Ein). The small transient decrease in medullary tissue electrolytes observed with higher peptide doses does not support solute wash-out as an important mechanism of increased sodium excretion.[1]References
- Atrial peptide natriuresis in the rat without genuine rise in filtration rate or wash-out of medullary electrolytes. Badzyńska, B., Sadowski, J., Dobrowolski, L. J. Physiol. (Lond.) (1990) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
