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Influence of TRPV1 and/or TRPV4 receptors on osmoregulatory thirst in mice (683.2)
Author(s) -
Kinsman Brian,
Cowles James,
Browning Kirsteen,
Stocker Sean
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.683.2
Subject(s) - thirst , trpv1 , trpv4 , transient receptor potential channel , chemistry , medicine , receptor , endocrinology , lamina terminalis , mannitol , median preoptic nucleus , hypothalamus , biology , biochemistry , angiotensin ii , subfornical organ
Recent in vitro studies suggest that hypothalamic osmolality‐sensing is mediated by either the transient receptor potential vanilloid‐1 (TRPV1) or vanilloid‐4 (TRPV4) channel expressed by neurons in the organum vasculosum of the lamina terminalis (OVLT). This study assessed whether deletion of TRPV1 and/or TRPV4 channels altered thirst responses to hyperosmolar stimuli. Wild‐type (WT), TRPV1‐/‐, TRPV4‐/‐, and TRPV1‐/‐V4‐/‐ mice (n = 9‐12 per genotype) ingested similar volumes of water 1 hr after sc injection (0.3mL) of 0.5M NaCl (0.37±0.03, 0.39±0.04, 0.42±0.04, 0.38±0.05 mL; P > 0.4) or 1.0M NaCl (0.89±0.06, 0.95±0.04, 1.07±0.11, 1.02±0.15 mL; P > 0.4). Similar results were observed after injection of 0.7M mannitol (0.38±0.06, 0.36±0.02, 0.31±0.04, 0.33±0.05 mL; P > 0.4). In addition, sole access to 2% NaCl for 48 hrs yielded similar increases in water intake across strains (0.22±0.03, 0.31±0.07, 0.21±0.02, 0.18±0.05 mL; P > 0.4). In a final experiment, injection of 0.5M NaCl generated similar increases in the number of OVLT Fos‐positive nuclei (21±4, 23±4, 16±4, 15±2; P > 0.2) across all genotypes. This investigation suggests that TRPV1 and TRPV4 receptors are not the central osmolality‐sensors that mediate osmotically‐stimulated thirst. Grant Funding Source : NIHHL113270, AHA EIA