title: [Protective effects of hydrogen sulfide on diaphragmatic muscle of Type 1 diabetic rats and its anti-apoptotic mechanisms].
abstract: OBJECTIVE
  To explore the protective effects of hydrogen sulfide (H2S) on diaphragmatic muscle of Type 1 diabetic rats and its anti-apoptotic mechanism.
  
  
  METHODS
  Thirty male Sprague Dawley rats were randomly divided into a control group, a diabetes group and a treatment group (n=10 per group). Streptozotocin (i.p.) was utilized to establish a rat model of Type 1 diabetes mellitus (DM). The DM rats were treated with NaHS solution (i.p.). After 8 weeks, the diaphragmatic muscle contractility was assessed by isolated diaphragmatic strips experiments. The peak twitch tension (Pt), maximum tetanic tension (Po), time to peak contraction (CT), half relaxation time (1/2RT) and maximal rates of contraction/relaxation (±dT/dtmax) were measured. The alterations of diaphragmtic ultrastructure were observed by electron microscopy. The content of malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and caspase-3 were analyzed by spectrophotometric method. The expressions levels of Bcl-2 and Bax mRNA in diaphragmatic muscle were detected by RT-PCR.
  
  
  RESULTS
  Compared with the control group, in the diabetic group, the Pt, Po and ±dT/dtmax were significantly reduced (all P<0.01), while CT and 1/2RT were significantly increased (both P<0.01); ultrastructure in the diaphragmatic muscle were obviously changed; the content of MDA and the activity of caspase-3 were increased (both P<0.01), while the activity of SOD was decreased (P<0.01); the ratio of Bcl-2/Bax at mRNA level was decreased (P<0.01). Compared with the diabetes group, in the treatment group, the diaphragm contractility and ultrastructural damage were improved; the content of MDA and the activity of caspase-3 were decreased (P<0.05, P<0.01 respectively), while the activity of SOD was increased (P<0.01), the ratio of Bcl-2/Bax at mRNA level was also increased (P<0.01).
  
  
  CONCLUSIONS
  The exogenous H2S can protect diaphragmatic muscle of Type 1 diabetic rats, which is related to reducing oxidative damage and suppressing cell apoptosis.
authors.affiliation: Department of Physiology, Bengbu Medical College, Bengbu Anhui 233030, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Yang
authors.affiliation: Department of Physiology, Bengbu Medical College, Bengbu Anhui 233030, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Jia
authors.affiliation: Department of Physiology, Bengbu Medical College, Bengbu Anhui 233030, China.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Guo
authors.affiliation: Department of Physiology, Bengbu Medical College, Bengbu Anhui 233030, China.
authors.forename: Xiaofen
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Physiology, Bengbu Medical College, Bengbu Anhui 233030, China.
authors.forename: Shanfeng
authors.initials: S
authors.lastname: Ma
authors.affiliation: Department of Physiology, Bengbu Medical College, Bengbu Anhui 233030, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Gao
authors.affiliation: Department of Physiology, Bengbu Medical College, Bengbu Anhui 233030, China.
authors.forename: Sudong
authors.initials: S
authors.lastname: Guan
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental; D003964:Diaphragm / Q000187:drug effects*; D006862:Hydrogen Sulfide / Q000494:pharmacology*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D009119:Muscle Contraction / Q000187:drug effects; D018384:Oxidative Stress; D051381:Rats; D017207:Rats, Sprague-Dawley; D013440:Sulfides; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D013440:Sulfides; D008315:Malondialdehyde; D013482:Superoxide Dismutase; C505410:Casp3 protein, rat; D053148:Caspase 3; C025451:sodium bisulfide; D006862:Hydrogen Sulfide