title: Hydrogen sulfide attenuates hypoxia-induced respiratory suppression in anesthetized adult rats.
abstract: Our previous study in vitro showed that hydrogen sulfide (H2S) could protect the medullary respiratory centers from injury induced by acute hypoxia in brainstem slices of neonatal rats. The present study was carried out to determine if H2S could exhibit similar protective effects in adult rats and to explore the underlying mechanisms of its protection. It was observed that hypoxia induced a diphasic respiratory response, an excitatory phase followed by an inhibitory one, as indicated by an increase followed by a decrease in frequency of rhythmic discharge of the diaphragm. Nissl staining revealed that some of the neurons in the medullary respiratory related nuclei were impaired in hypoxia rats. Hypoxia led to increases in the content of malondialdehyde (MDA) and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), as well as a decrease in the level of Bcl-2 mRNA of the medulla oblongata. Intracerebroventricular injection of 2.5mM NaHS (a donor of H2S) or L-cysteine (L-Cys, a substrate for H2S) could prevent inhibitory respiratory effect occurred in the rats with hypoxia. Exogenous application of NaHS and L-Cys could also reduce the content of MDA and the activities of SOD and GSH-Px, and increase the level of Bcl-2 mRNA expression of medulla oblongata caused by hypoxia. These results indicate that H2S could protect the medullary respiratory centers against injury induced by acute hypoxia in adult rats partly due to its anti-oxidant and anti-apoptotic effects.
authors.affiliation: Department of Physiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, China; College of Medicine, Henan University, Kaifeng, Henan 475004, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Physiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, China.
authors.forename: Li
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Physiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, China.
authors.forename: Xuefei
authors.initials: X
authors.lastname: Hou
authors.affiliation: Department of Physiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Department of Physiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan 610041, China. Electronic address: yzheng@scu.edu.cn.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zheng
mesh_terms: D000758:Anesthesia; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002317:Cardiovascular Agents / Q000494:pharmacology*; D003545:Cysteine / Q000494:pharmacology; D005979:Glutathione Peroxidase / Q000378:metabolism; D006862:Hydrogen Sulfide / Q000494:pharmacology*; D000860:Hypoxia / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D008315:Malondialdehyde / Q000378:metabolism; D008526:Medulla Oblongata / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology; D009474:Neurons / Q000187:drug effects* / Q000473:pathology / Q000502:physiology; D018696:Neuroprotective Agents; D017207:Rats, Sprague-Dawley; D012119:Respiration / Q000187:drug effects*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D002317:Cardiovascular Agents; D018696:Neuroprotective Agents; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D003545:Cysteine; D006862:Hydrogen Sulfide
keywords: Adult rat; Hydrogen sulfide; Hypoxia; Medullary respiratory center; Respiratory regulation