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Abstract 121: Afferent Renal Nerve Chemo- and Mechanosensitive Responses and the Modulation of Sodium Homeostasis and Blood Pressure
- Source :
- Hypertension. 68
- Publication Year :
- 2016
- Publisher :
- Ovid Technologies (Wolters Kluwer Health), 2016.
-
Abstract
- Aim: We hypothesize that challenges to sodium homeostasis differentially activate chemo- vs. mechanosensitive afferent renal nerves to evoke sympathoinhibition, sodium homeostasis and normotension in the Sprague-Dawley (SD) rat. Methods: Conscious SD rats, post sham (S) or afferent renal nerve ablation (Renal-CAP; capsaicin 33 mM) underwent IV volume expansion (VE; 5% BW) or IV sodium loading (1M NaCl Infusion – constant infusion volume) and HR, MAP, natriuresis and PVN neuronal activation (c-Fos expression) were assessed (N=4/gp). Naïve SD rats were fed a 0.6% (NS) or 4% NaCl (HS) diet for 21 days and afferent renal nerve activity was assessed as norepinephrine (NE) (1250 pmol) and NaCl-evoked (450mM) substance P (SP) release in a renal pelvic assay (N=4/gp). Radiotelemetered SD rats post S or Renal-CAP immediately prior a 0.6% (NS) or 4% NaCl (HS) diet underwent continuous MAP monitoring. On day-21 plasma and renal NE content was assessed (N=5/group). Results: Renal-CAP attenuated the natriuretic and PVN parvocellular responses to IV VE (peak UNaV [μeq/min]; S 43±4 vs Renal-CAP 26±6, P Conclusion: The mechanosensitive afferent renal nerves mediate acute natriuresis and blood pressure regulation via activation of PVN sympathoinhibitory neurons. During HS intake the afferent renal nerves counter the development of salt-sensitive hypertension via a mechanism involving increased mechano but not chemosensitive afferent nerve responsiveness to potentiate sympathoinhibition.
Details
- ISSN :
- 15244563 and 0194911X
- Volume :
- 68
- Database :
- OpenAIRE
- Journal :
- Hypertension
- Accession number :
- edsair.doi...........06aca70eb66510bacd056e944a722028