Premium
Nucleus tractus solitarii (nTS) reactive oxygen species (ROS) contribute to acute intermittent hypoxia (AIH)‐induced phrenic nerve long‐term facilitation (pLTF)
Author(s) -
Kleiber Allison Christine,
Ostrowski Daniela,
Kline David D.,
Heesch Cheryl M.,
Hasser Eileen M.
Publication year - 2013
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.27.1_supplement.697.27
Subject(s) - intermittent hypoxia , hypoxia (environmental) , splanchnic , phrenic nerve , anesthesia , microinjection , medicine , biology , endocrinology , pharmacology , chemistry , respiratory system , obstructive sleep apnea , hemodynamics , oxygen , organic chemistry
Rats exposed to AIH exhibit cardiorespiratory changes associated with obstructive sleep apnea, such as pLTF, including elevated phrenic (PNA) and sympathetic (SNA) nerve activity that persist ≥ 60 min after the final hypoxic bout (AIH‐pLTF). The nTS in the medulla integrates and modulates primary cardiorespiratory input. Also, ROS modulate nTS neuronal function and are increased by intermittent hypoxia. Therefore, we hypothesized that nTS ROS contribute to AIH‐pLTF. We decreased ROS in the nTS by bilateral microinjection of catalase (CAT, 500 U/ml; 90 nl) prior to each of 10 45‐sec bouts of 10% O 2 separated by 5‐min recovery periods (100% O 2 ) in anesthetized, ventilated, vagotomized, and paralyzed rats. AIH alone or with nTS aCSF produced AIH‐pLTF (60 min post‐AIH; integrated PNA amplitude: 451±170% baseline, n=4; int.splanchnic SNA: 183±50% baseline, n=4). Following CAT, increased PNA and SSNA due to each hypoxic bout were preserved. However, CAT attenuated AIH‐pLTF (int.PNA: 0±7% baseline, n=3; int.SSNA: 2±3% baseline, n=2). AIH did not alter arterial pressure or heart rate. Attenuation of AIH‐pLTF by nTS CAT indicates that ROS, likely H 2 O 2 , within the nTS normally contribute to AIH‐pLTF. HL98602