title: [Involvement of endogenous carbon monoxide in regulation of respiratory rhythm in vitro].
abstract: The aim of the present study was to investigate the effect of endogenous carbon monoxide (CO) on respiratory rhythm. The experiments were carried out on the medullary slices of newborn Sprague-Dawley rats. The rhythmic discharge frequency (DF) of hypoglossal rootlets was taken as an index of rhythmic respiratory activity. The slices of medulla oblongata were superfused with ZnPP-9 (inhibitor of heme oxygenase), CO and hemin (substrate of heme oxygenase), respectively, to observe their effects on respiratory rhythm. The preparations were divided into 5 groups: control group of artificial cerebrospinal fluid (ACSF), group of ZnPP-9, group of exogenous CO, group of hemin and group of ZnPP-9 + hemin. The results obtained were as follows. In ZnPP-9 group, the rhythmic DF of the hypoglossal rootlets was increased (P<0.05); while in exogenous CO group, it was decreased (P<0.05). In the groups of hemin and ZnPP-9 + hemin, the rhythmic DF of the hypoglossal rootlets was increased (P<0.05). It is suggested that endogenous CO may play an important role in the regulation of respiratory rhythm.
authors.affiliation: Department of Physiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China.
authors.forename: Wen-Xing
authors.initials: WX
authors.lastname: Yang
authors.forename: Qi-Lan
authors.initials: QL
authors.lastname: Zhang
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Hu
authors.forename: Jin
authors.initials: J
authors.lastname: Liu
authors.forename: Yong-Bo
authors.initials: YB
authors.lastname: Li
authors.forename: Hua
authors.initials: H
authors.lastname: Zhou
authors.forename: Yu
authors.initials: Y
authors.lastname: Zheng
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002248:Carbon Monoxide / Q000502:physiology*; D005260:Female; D006427:Hemin / Q000494:pharmacology; D007002:Hypoglossal Nerve / Q000187:drug effects / Q000502:physiology; D008297:Male; D011524:Protoporphyrins / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012119:Respiration
chemical_list: D011524:Protoporphyrins; C017803:zinc protoporphyrin; D006427:Hemin; D002248:Carbon Monoxide