The mechanisms underlying the net fluid/electrolyte gain during pregnancy are not fully understood. Utilizing virgin, pregnant (7, 16 and 21 days gestation), estradiol-17beta- or progesterone-treated female rats, we have examined the role of atrial natriuretic peptide (ANP) and of its receptors in the adaptation of body fluid homeostasis during pregnancy. Pregnancy and progesterone attenuate the ANP-mediated inhibition on aldosterone production in adrenal zona, glomerulosa (ZG) cells. The ribonuclease protection assay and Western analysis revealed that ZG natriuretic peptide guanylyl cyclase-linked (GC) receptors are mainly GC-A and that they are downregulated by pregnancy. In addition, pregnancy downregulates GC-A and GC-B receptors in the uterus; however, it does not modulate GC-linked receptors in the lung. It is concluded that the downregulation of ZG GC-A receptors could lead to a decrease in the aldosterone-suppressant effects of ANP and that the decrease in uterine GC-A and GC-B receptors could lead to a decrease in the tocolytic effects of ANP during pregnancy.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.20886 |
| Date | January 1997 |
| Creators | Vaillancourt, Patrice A. |
| 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 | Master of Science (Department of Physiology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001605446, proquestno: MQ44307, Theses scanned by UMI/ProQuest. |
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