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K252a inhibits carotid body growth but not oxygen sensitivity (1177.2)
Author(s) -
Bavis Ryan,
Logan Sarah,
Blegen Halward,
Fallon Sarah
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.1177.2
Subject(s) - carotid body , glomus cell , tropomyosin receptor kinase b , medicine , endocrinology , neurotrophic factors , receptor , neurotrophin , antagonist , electrophysiology
Brain‐derived neurotrophic factor (BDNF) supports innervation of the carotid body by afferent neurons (Hertzberg et al., Dev. Biol. 166:801‐811, 1994). Carotid body glomus cells express TrkB receptors as well, but the role of BDNF in carotid body growth and O 2 sensitivity has not been studied. Neonatal rats were injected with the TrkB antagonist K252a (100 µg kg ‐1 , i.p.) or vehicle (25% DMSO) twice daily on postnatal days P0‐P6 and studied on P7. Carotid body volume was decreased by 35% after chronic K252a ( P <0.001). However, single‐unit chemoafferent responses to 5% O 2 , measured in vitro , were unaffected by K252a administration. Ventilatory responses to 12% O 2 , measured by head‐body plethysmography, were also normal. Similar results were obtained for hypoxic chemoafferent and ventilatory responses after acute K252a administration. These data suggest that BDNF regulates carotid body growth but does not modulate glomus cell O 2 sensitivity. Grant Funding Source : Supported by NIH grant P20 GM‐103423 (Maine INBRE)