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EFFECTS OF ANGIOTENSIN II ON SYMPATHETIC GANGLIONIC TRANSMISSION IN VIVO
Author(s) -
McAllen Robin,
Bratton Bradford
Publication year - 2015
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.29.1_supplement.830.4
Subject(s) - depolarization , ganglion , sympathetic ganglion , medicine , endocrinology , angiotensin ii , chemistry , sympathetic nervous system , anatomy , receptor , blood pressure
Sympathetic ganglion cells express type 1 angiotensin II (Ang II) receptors, but their functional role in vivo has not been tested. Intracellular recordings were made from the L3 paravertebral ganglion of urethane‐anesthetized, ventilated rats, following established procedures (Bratton et al. J. Physiol 588, 1647‐59, 2010). The ganglion, with preganglionic inputs preserved, was pinned to a plate and superfused with warmed Krebs' solution to which Ang II was added in concentrations of 0.2‐0.5 mM. Ten L3 ganglion cells showed ongoing spikes and subthreshold EPSPs that were strongly barosensitive, indicating that they were of muscle vasoconstrictor‐type. Ang II at these concentrations caused no consistent depolarization and no enhancement of ongoing spike activity in 9/10 cells, the tenth cell giving equivocal responses. By contrast, 2/2 neurons recorded from the prevertebral renal ganglion, which were also strongly barosensitive, responded to Ang II (0.2‐0.5 mM) with depolarization and increased action potential firing. This confirmed previous in vitro findings but showed additionally that Ang II increases the probability of preganglionic inputs to renal ganglion cells triggering postganglionic action potentials. We conclude that the ganglionic actions of Ang II are selective, promoting ganglionic transmission in renal (prevertebral) but not muscle vasoconstrictor‐ type (paravertebral) sympathetic neural pathways. Supported by NHMRC.