ABSTRACT
Objective To investigate the effect of chronic low-frequency electrical stimulation on the structural and metabolic changes of diaphragm of emphysema rabbits.Methods The rabbit model of emphysema was made by papain-inhaling of ultrasonic atomization once a week for 3 weeks in 30 adult Japanese rabbits,6 receiving 10 Hz chronic low frequency electrical stimulation,6 receiving 40 Hz,and 6 receiving(10+40)Hz.Other 6 emphysema rabbits and 6 normal rabbits served as control.An enzyme chemical method was used to observe the changes in the enzyme activities of sarcoplasmic reticulum Ca2+-ATPase,succinate dehydrogenase(SDH)and the lactate dehydrogenase(LDH)and changes in MHC in control group,emphysema group,and emphysema+chronic low frequency electrical stimulation group.Results Following chronic electrical stimulation using 40 Hz,10 Hz,and(10+40)Hz,the relative contents of MHC were increased in the diaphragmatic muscle of rabbits with emphysema.The percentage of MHC-Ⅰ was significantly increased in the 10 Hz group,while that of MHC-Ⅱa was significantly increased in the(10+40)Hz group.Following chronic electrical stimulation using 40 Hz and(10+40)Hz,diaphragmatic muscle SR Ca2+-ATPase activity was increased in rabbits with emphysema(P
ABSTRACT
Objective To investigate the effect of chronic electrical stimulus (CES) of low frequency and physiological frequency on diaphragmatic subtype of myosin heavy chain (MHC) and mechanical characteristic in rabbits with emphysema. Methods The rabbit model of emphysema was made by inhaling papain of ultrasonic atomization once a week for 3 weeks in 30 adult Japanese rabbits, 6 receiving 10 Hz chronic low-frequency electrical stimulation, 6 receiving 40 Hz, 6 receiving 10 Hz plus 40 Hz. Another 6 emphysema rabbits and 6 normal rabbits served as control. The twitch tension (Pt), titanic tension (Po), time to peak tension (TPT), half-relaxation time (1/2Rt), fatigue index (FI) and fatigue recovery index (FRI) were measured and SDS-polyacrylamide gel electrophoresis was used to observe the changes in subtype of MHC in control group, emphysema group, CES groups respectively. Results ①Following chronic electrical stimulus of 40 Hz, 10 Hz, and (10+40) Hz, the relative contents of MHC were increased in diaphragmatic muscle of rabbits with emphysema. The percentage of MHC-I was significantly increased in the 10 Hz group, while that of MHC-I and MHC-IIa were significantly increased in the (10+40) Hz group. ②Following chronic electrical stimulation using 40 Hz and (10+40)Hz, diaphragmatic muscle Pt and Po were significantly increased in rabbits with emphysema, TPT and 1/2Rt were significantly reduced, and FI and FRI were significantly decreased (P
ABSTRACT
Objective To investigate the effect of chronic ultra-low frequency electrical stimulation on mechanical characteristic of diaphragmatic muscle of emphysema rabbit.Methods The rabbit model of emphysema was made by inhaling papain of ultrasonic atomization once a week for 3 weeks in 24 adult Japanese rabbits,6 receiving 10 Hz chronic ultra-low frequency electrical stimulation,6 receiving 40 Hz,6 receiving 2.5 Hz and 40 Hz.Another 6 rabbits served as control.The twitch tension (Pt),titanic tension(Po),time to peak tension(TPT),half-relaxation time(1/2RT),fatigue index(FI) and fatigue recovery index(FRI) were measured in control group,emphysema group,emphysema+chronic ultra-low frequency electrical stimulation groups.Results As compared with the control rabbits, Pt and Po decreased,TPT and 1/2RT prolonged,FI and FRI increased in the only emphysema rabbits.Pt and Po were higher,TPR and 1/2Rt was shorter in the only emphysema rabbits than the rabbits in 40 Hz and(2.5+40) Hz groups(P0.05),more increase in FR and FRI(P