Effect of long-term nitrous oxide inhalation on the cardiac function in rats
- VernacularTitle:长期吸入笑气对大鼠心肌功能的影响
- Author:
Na SUN
;
Jianqing DU
;
Zhiyong WANG
;
Surong LIU
;
Yan XU
;
Juanxia ZHU
;
Qiang LI
- Publication Type:Journal Article
- Keywords:
nitrous oxide;
action potential;
immunohistochemistry;
angiotensin Ⅱ;
nitricoxide synthase
- From:
Journal of Xi'an Jiaotong University(Medical Sciences)
2010;31(1):71-74,83
- CountryChina
- Language:Chinese
-
Abstract:
Objective To observe whether or not long-term inhalation of nitrous oxide can affect the cardiac function in rats. Methods Sprague-Dawley rats of either sex were randomly divided into four groups. Group A: inhaled common air for 50 days as control; Group B: inhaled 500mL/L N_2O for 15 days, two hours every day; Group C: inhaled 500mL/L N_2O for 30 days, two hours every day; Group D: inhaled 500mL/L N_2O for 50 days, two hours every day. Float glass intracellular microelectrode recording technique was used for observation of the duration (MAPD_(90), MAPD_(50) and MAPD_(20)) and amplitude of action potentials (APs) of left ventricular muscle cells in vitro. Angiotensin-2 (Ang-2) and eNOS were detected by immunohistochemical technique. Results ① Compared with that in Group A, the Aps duration of left ventricular muscle cells (MAPD) in Group B had no significant change while the MAPDs in Group C and Group D were extended significantly. There were no significant differences among the four groups in Aps amplitude. ② The expression of Ang-2 did not differ significantly between Group B and Group A. The expression level was higher in Group C and D than in Group A. ③ The expression level of eNOS was significantly lower in Group C and D than in Group A (P<0.05). Conclusion Long-term inhalation of N2O can significantly affect the cardiac function in rats, which may be related to higher expression of AngⅡin the heart induced by the long-time excitation of sympathetic nerves.
