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Pre‐Botzinger Complex (PBC) Plays An Important Role in the Hyperventilatory Response to Intravenous Injection of 5HT 1A R Agonist in Anesthetized Rats
Author(s) -
Zhuang Jianguo,
Zhang Cancan,
Xu Fadi
Publication year - 2012
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.26.1_supplement.895.4
Subject(s) - microinjection , hyperventilation , agonist , medicine , 5 ht receptor , endocrinology , 8 oh dpat , chemistry , anesthesia , serotonin , receptor
Systemic administration of 8‐hydroxy‐2‐(di‐n‐propylamino)tetralin (DPAT), a 5HT 1A R agonist, causes a hyperventilation via elevating fR in animals. It also prevents peripheral and central mu‐opioid receptor‐induced apnea (Zhuang et al, EB 2010; Sahibzada et al, JPET 2000). Because the PBC containing 5HT 1A Rs is critical in respiratory rhythm, we examined whether local 5HT 1A Rs are involved in the evoked hyperventilation. In anesthetized rats, the cardiorespiratory responses to systematic DPAT challenge (100 μg/kg, iv) were performed 1 hr before and 5 min after bilateral microinjection of WAY‐100635, a selective 5HT 1A R antagonist (20 mM, 10 nl), into the PBC via a ventral approach. Our results showed that: 1) DPAT doubled VE primarily via elevating fR associated with a hypotension (−34%) and little change in HR, which recovered ~60 min later; 2) microinjection of WAY‐100635 into the PBC did not alter baseline cardiorespiratory variables, but strikingly attenuated (50% reduction) the DPAT‐induced hyperventilation and shortened the recovery period to ~30 min with the hypotension unchanged; and 3) the same microinjection made 1 mm rostral to the PBC or vehicle microinjected into the PBC failed to affect this evoked hyperventilation. Our data suggest that systemic DPAT challenge causes the hyperventilation largely through acting on PBC 5HT 1A Rs (Supported by HL 107462 and ALA RG‐191095‐N).