[Effects of hydrogen sulfide on contraction capacity of diaphragm from type 1 diabetic rats].
OBJECTIVE
To investigate the effects of hydrogen sulfide (H2S) on contraction capacity of diaphragm in type 1 diabetic rats.


METHODS
Thirty-two male SD rats were randomly divided into a normal group (NC), a diabetic group (DM), a NaHS treatment group (DM+NaHS) and a NaHS group (NaHS) (n=8). Intraperitoneal injection of streptozotocin was utilized to establish diabetic rat model. After the modeling, the rats in the DM+NaHS and the NaHS groups were intraperitoneally injected with 28 μmol/kg NaHS solution. 8 weeks later, the diaphragm contractility was assessed by isolated draphragm strips perfusion. The peak twitch tension (Pt), maximum tetanic tension (Po) and maximal rates of contraction/relaxation (±dT/dtmax) were determined. The alterations in diaphragm ultrastructure were observed under electron microscopy. The diaphragm weight/body weight (DW/BW) was measured. The activities of succinic dehydrogenase (SDH), lactate dehydrogenase (LDH) and sarcoplasmic reticulum Ca2+ ATPase (SERCA) were analyzed by spectrophotometric method. The mRNA levels of SERCA and prospholamban (PLB) in diaphragm were detected by RT-PCR.


RESULTS
Compared with the NC group, there was no significant change in all measured index in the NaHS group (P>0.05), while Pt, Po and ±dT/dtmax were significantly decreased in the DM group (P<0.05). Transmission electron microscopy revealed obvious ultrastructural changes in the diaphragm. The DW/BW ratio and the activities of SDH, LDH and SERCA were decreased. The SERCA mRNA was decreased, while PLB mRNA was increased. Compared with the DM group, the diaphragm contractility and ultrastructure damage were improved in the DM+NaHS group. The DW/BW ratio and the activities of SDH, LDH and SERCA were increased. The SERCA mRNA was increased, while PLB mRNA was decreased (all P<0.05).


CONCLUSIONS
H(2)S can enhance the contraction capacity of diaphragm in type 1 diabetic rats, which is involved in regulating the activities of biological enzymes and the gene expressions of calcium regulatory proteins.
Department of Physiology, Bengbu Medical College, Bengbu Anhui 233030, China.
Qiang
Q
Jia
Department of Physiology, Bengbu Medical College, Bengbu Anhui 233030, China.
Shanfeng
S
Ma
Department of Physiology, Bengbu Medical College, Bengbu Anhui 233030, China.
Xiaofen
X
Liu
Department of Bioscience, Bengbu Medical College, Bengbu Anhui 233030, China.
Sai
S
Li
Center of Functional Experiment, Bengbu Medical College, Bengbu Anhui 233030, China.
Yuanyuan
Y
Wang
Department of Physiology, Bengbu Medical College, Bengbu Anhui 233030, China.
Qin
Q
Gao
Department of Physiology, Bengbu Medical College, Bengbu Anhui 233030, China.
Rui
R
Yang
D000818:Animals; D001835:Body Weight; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D003964:Diaphragm / Q000187:drug effects* / Q000648:ultrastructure; D006862:Hydrogen Sulfide / Q000494:pharmacology*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000378:metabolism; D013385:Succinate Dehydrogenase / Q000378:metabolism; D013440:Sulfides / Q000494:pharmacology
D012333:RNA, Messenger; D013440:Sulfides; D007770:L-Lactate Dehydrogenase; D013385:Succinate Dehydrogenase; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; C025451:sodium bisulfide; D006862:Hydrogen Sulfide