Using the rat as a model we tested the hypothesis that pregnancy might lead to an attenuation of the diuretic/natriuretic effects of atrial natriuretic factor (ANF) to allow physiologically required fluid expansion. Our studies revealed that this was indeed the case. Effects of ANF on fluid and sodium excretion as well as on glomerular filtration rate were significantly reduced during pregnancy This decrease in the renal effects of ANF during pregnancy was not associated with any changes in the pharmacokinetics or renal metabolism of ANF. However, binding studies demonstrated a significant decrease in guanylyl cyclase (GC)-linked ANF receptors and a decrease in ANF stimulated cGMP production in glomeruli and papillae of pregnant rats. The ribonuclease protection assay and Western blot analysis revealed that pregnancy caused a significant decrease in GC-A-linked ANF receptors in renal papillae. It is concluded that pregnancy is associated with attenuation of the renal effects of ANF and this is due to a downregulation of GC-A-linked ANF receptors which might reflect physiological adjustment to facilitate fluid/electrolyte expansion.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.34762 |
| Date | January 1997 |
| Creators | Omer, Saeed. |
| Contributors | Mulay, Shree (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Physiology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001605582, proquestno: NQ44541, Theses scanned by UMI/ProQuest. |
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