[Experimental study on effect of Shenmai injection in improving contractility of fatigue diaphragm in rats].
OBJECTIVE
To study and compare the effects of Shenmai Injection (SMI) and aminophylline on pathogenesis and developing process of diaphragmatic fatigue.


METHODS
SMI group, aminophylline group, SMI plus aminophylline group and control group of isolated rat's diaphragmatic muscular strip of equal length were set up, and electric stimulation was applied. Changes of related parameters in the fatigue inducing and recovery process were estimated.


RESULTS
During fatigue inducing process, the lowering on maximal rates of relaxation (dR/dtmax) was earlier than that on maximal contraction peak (Pt) and contraction rate (dT/dtmax), and restoring of these parameters were restored later and incompletely. SMI could prolong the time Pt needed for reducing 50%, speed up the restoration of Pt. Although aminophylline could increase Pt, it shortened the fatigue inducing time and postponed the recovery.


CONCLUSIONS
Disturbance in the function of relaxation plays important role in diaphragm fatigue induction. Through strengthening the capability to relax, SMI could improve the function of fatigue diaphragm. Aminophylline would damage the relaxation function together with the increasing contraction of diaphragm simultaneously, and this side-effect could be antagonised partly by SMI.
Ye
D
D
Key Lab of Pulmonary Diseases of Ministry of Health, Tongji Medical University, Wuhan (430030).
Wu
P
P
Niu
R
R
D000628:Aminophylline / Q000494:pharmacology; D000818:Animals; D003964:Diaphragm / Q000502:physiology*; D004357:Drug Synergism; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D004558:Electric Stimulation; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D018763:Muscle Fatigue / Q000502:physiology*; D009126:Muscle Relaxation / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar
D004365:Drugs, Chinese Herbal; D000628:Aminophylline