The Change Of Plasma Elastin Peptide In Septic Shock Rats And The Effect Of Doxycycline

Objective Through observing the change of the contents of plasms elastin peptide and the change of angiotasis in septic shock rats,and the effect of its inhibitor (doxycyline),to investigate the effects that EP engender On the hemodynamics during septic shock.Methods Thirty healthy male Sprague-Dawley rats, weighing 200-250g were randomly divided into 3 groups as follow(n=10):Before the operation, a blood pressure transducer were implanted into the common carotid artery for continuous registration of mean arterial blood pressure(MAP).①sham-operated control group(Sham group):do not ligation and punct cecum, the other processes are coincide with cecal ligation and puncture group.after the operation, giving sodium chloride 10ml-kg-1-h-1till executed.②cecal ligation and puncture group(CLP group):to make a two-three centimeter cut in the middle of the anterior belly of the rats,liberating the mesentery and cecum, using silk suture of 3-0 ligate the root part of the cecum, using the pin of 12 to make three or five cut in the root part of cecum.two cut are part from 3 centimeter, taking back the intestine, suturing the cut and closing the abdominal part. disinfecting and bandaging the wound. after the operation, giving sodium chloride 10ml-kg-1·h-1 till executed.③doxycycline group(DOX group):the processes are coincide with cecal ligation and puncture group.after the operation, giving0.75% doxycycline 10ml·kg-1·h-1 till executed. At the time of Oh,4,8,12,16h, collecting the blood from common carotid artery. Use the method of ELISA to detect the level of EP. Execute the rats at the time of 16h, open the thoracic part and expose the heart, separating the thoracic aorta quickly, detecting the angiotasis of the thoracic aorta.Results①General state and morphology:compared with Sham group, the activity of the CLP group rats decreased, lethargy, piloerection, tachypnea, pyuria, angle of eye have exudates and so on.After executig the rat, the rats of CLP group have blood exudates in abdominal cavity, evil smelling, cecum is swelling and black, gangrene and accretion.The jejunum have gas and the organ of liver, lung, kidney are hyperemia and edema,having petechia and ecchymosis and so on. But every index significantly improved in group of DOX.②The change of mean arterial blood pressure(MAP):after the model of CLP,the MAP decrease gradually, compared to the sham group 0h,4h,the MAP did not have meaning of statistics(P> 0.05), but 8h,12h,16h, having significant statistics(P<0. 05).The decrease extent of DOX group is lessen obviously.after 4h, compared to the CLP group, the MAP have significantly meaning of statistics at each time point(P< 0.05).but compare to the sham group, did not have meaning of statistics(P>0.05).③The change of plasma elastin peptide(EP):the EP of the sham group is steady at all the time point.the EP of the CLP group increased remarkably, as time prolonged, the content of EP were increased, highest at hour 16(P<0.05).Compared to the CLP group, the EP of the DOX group reduced manifest and have significantly meaning of statistics at each time point(P<0.05).but compared to the sham group, have no significantly meaning of statistics(P>0.05).④Determination the angiotasis of thoracic aorta:the angiotasis of thoracic aorta in CLP group rats were significantly lower than in sham group(P<0.05).The largest contract tension were significantly higher in the DOX group than in the CLP group(P<0.05).but get close to the sham group(P>0.05).Conclusions During the septic shock,, the extent of plasma elastin peptide are higher significantly, as the time prolonged, rised;The higher EP leads to the degression of angiotasis, the weaken of activity.The doxycycline can inhibit the activity of plasma elastin peptide enzyme.to make the extent of EP lower.lt may be amendment the activity of blood vessel.