RESUMO
Objective:To observe the effects of electroacupuncture preconditioning on the autophagy-related pathway protein kinase B (Akt)/mammalian target of rapamycin (mTOR) in myocardial tissue of rats with myocardial ischemia reperfusion injury (MIRI); To investigate the protective mechanism of "Neiguan"(PC 6) on myocardial injury.Methods:Totally 48 SD rats were randomly divided into blank group, sham-operation group, model group and Neiguan group ( n=12 in each group). The Neiguan group was applied to bilateral "Neiguan"(PC 6) by electroacupuncture for 30 min, once daily for consecutive 7 days before model replication. Except in the blank group, the MIRI model was established by ligation of the descending anterior branch of the left coronary artery in the rest groups after the intervention. The histomorphological changes in the myocardium of the rats were observed by HE staining, and the expression levels of Akt, phosphorylated Akt (p-Akt), mTOR and phosphorylated mTOR (p-mTOR) in the myocardium were measured by protein immunoblotting. The ratio of p-Akt/Akt and p-mTOR/mTOR was calculated. Results:In the blank group, the myocardial fibres were arranged regularly and neatly, and no inflammatory cell infiltration or haemorrhage was seen in the interstitium; in the sham-operation group, the arrangement of myocardial fibers was slightly irregular, no rupture was found, and a small amount of myocardial fiber gap was slightly enlarged; in the model group, the distribution of myocardial fibers was disordered, hypertrophic cardiomyocytes increased, some mitochondria were red and swollen or the outer membrane was ruptured, and inflammatory infiltration and hemorrhage were seen in the interstitium; the extent of myocardial lesions in the Neiguan group was less than that in the model group, with a small amount of interstitial hemorrhage and inflammatory cell infiltration. There was no statistical significance in the levels of Akt and mTOR in the myocardial tissues of the rats in each group ( P>0.05); compared with the sham-operation group, the levels of p-Akt, p-mTOR and p-Akt/Akt, p-mTOR/mTOR in the model group decreased ( P<0.01); compared with the model group, the levels of p-Akt, p-mTOR and p-Akt/Akt, p-mTOR/mTOR in the Neiguan group increased ( P<0.01). Conclusion:Electroacupuncture preconditioning may inhibit excessive autophagy by activating the Akt/mTOR pathway in cardiomyocytes of MIRI rats, thereby exerting a protective effect on the myocardium.
RESUMO
Objective: To observe the effect of electroacupuncture (EA) at Zusanli (ST 36) on the gastrointestinal motility and the ultrastructures of pacemaker cells [the interstitial cells of Cajal (ICC)] in diabetic gastroparesis (DGP) rats and explore the mechanism of EA for DGP.Methods: A total of 50 Sprague-Dawley (SD) rats were randomly divided into group A, group B, group C, group D and group E, with 10 rats in each group. Group A was the blank control; a single intraperitoneal injection of 2% streptozotocin (STZ) was performed in rats of group B, group C, group D and group E, with high glucose and high fat diet for 8 weeks to establish the DGP rat models. Group B was the model group and the rats did not receive any treatment; group C was EA at acupoint group and the rats received EA at Zusanli (ST 36), Liangmen (ST 21) and Sanyinjiao (SP 6); group D was EA at non-acupoint group and the rats received EA at the control points of Zusanli (ST 36), Liangmen (ST 21) and Sanyinjiao (SP 6); group E was metoclopramide group and the rats were treated by intragastric administration of metoclopramide. Blood glucose was detected using ONE TOUCH blood glucose meter; gastric emptying rate and small intestine migration rate were measured using intragastric phenol red; ultrastructures of gastric antrum ICC were detected by transmission electron microscopy.Results: The differences of blood glucose between group B, group C, group D, group E versus that of group A were statistically significant after modeling (P<0.01); after treatment, the differences of blood glucose between group D, group E versus that of group C were statistically significant (P<0.05,P<0.01); the gastric emptying rate of rats in group B was statistically significant different from that in group A (P<0.01); the gastric emptying rate of rats in group C was statistically significant different from that in group B (P<0.01). The migration rates of rats' small intestines in group B, group C, group D and group E were all statistically significant different from that in group A (P<0.01); the migration rate of rats' small intestines in group C was statistically significant different from that in group B (P<0.01). The ultrastructure of rat's ICC in group B showed apoptosis compared with that in group A; rat's ICC in group C had complete basement membrane, more cytoplasm mitochondria, Golgi and rough endoplasmic reticulum, showing clear structure, occasional mitochondria swelling and gap junctions with adjacent smooth muscle cells; there were no significant differences between group D, group E versus group B.Conclusion: EA at Zusanli (ST 36) plus other acupoints can regulate the blood glucose and promote gastrointestinal motility in DGP rats, and the mechanism may be related to repairing the damaged ICC structure.
RESUMO
Objective: To observe the effect of electroacupuncture (EA) on the electrogastrogram and gastric antrum ghrelin in rats with diabetic gastroparesis (DGP). Methods: Fifty Sprague-Dawley (SD) rats were randomly divided into group A, group B, group C, group D and group E, 10 rats in each group. Group A was the blank control group without intervention. Group B, Group C, Group D and Group E were treated with single dose intraperitoneal injection of 2% streptozotocin (STZ), combined with 8-week high glucose and high fat diet to establish DGP rat models. Group B was the model group without treatment. Group C was the EA at acupoint group, was treated with EA at Zusanli (ST 36), Liangmen (ST 21) and Sanyinjiao (SP 6). Group D was the EA at non-acupoint group, was treated by EA at the control points of Zusanli (ST 36), Liangmen (ST 21) and Sanyinjiao (SP 6). Rats in the metoclopramide control group received 1.7% metoclopramide solution [10 mL/(kg·bw)] by gavage. Rat's blood glucose level was measured by blood glucose meter; gastric emptying rate was detected using phenol red as a marker; the electrogastrogram was detected by BL-420F biological function system; the protein level of ghrelin was detected by enzyme-linked immunosorbent assay (ELISA); the expression of ghrelin mRNA was detected by real-time polymerase chain reaction (RT-PCR). Results: Compared with group A, the blood glucose of group B, C, D and E were significantly increased before and after the treatment (all P<0.01); after treatment, the gastric emptying rate of group B was significantly decreased (P<0.01), the migration rates of small intestine in group B, C, D and E were significantly lower (all P<0.01), and the protein content of ghrelin in group C was significantly decreased (P<0.01); the expressions of ghrelin mRNA were significantly increased in group B, C, D and E (all P<0.01), the mean amplitudes of electrogastrogram in group B and D were significantly decreased (both P<0.01). After treatment, compared with group B, the blood glucose of group C was significantly decreased (P<0.05), the gastric emptying rate and small intestine migration rate were significantly increased in group C and E (P<0.05, P<0.01), the small intestinal migration rate was significantly increased in group D (P<0.05), the expression of ghrelin in protein and mRNA in group C was significantly lower (P<0.01), the expression of ghrelin mRNA in group E was significantly lower (P<0.05), and the mean amplitude of electrogastrogram in group C was significantly increased (P<0.05). After treatment, compared with group D, the protein and mRNA expressions of ghrelin in group C were significantly decreased (P<0.01). After treatment, compared with group E, the protein expression of ghrelin in group C was significantly decreased (P<0.01). Conclusion: EA at Zusanli (ST 36), Liangmen (ST 21) and Sanyinjiao (SP 6) could regulate the blood glucose level of DGP model rats, enhance electrogastrogram activity, promote gastric emptying, and regulate ghrelin expression in protein and mRNA.