Symbiosis international Deemed university
Sustainability standards, Sustainability practices, corporate social responsibility, sociology of minority, womens studies, Human resources Management, Organizational Behavior.
Fawzi A. Babiker, Aishah Al-Jarallah, and Shaji Joseph Springer Science and Business Media LLC
Fawzi Babiker, Aishah Al-Jarallah, and Shaji Joseph Public Library of Science (PLoS)
Background Accumulating evidence suggests a cardioprotective role of pacing postconditioning (PPC) maneuvers in animal models and more recently in humans. The procedure however remains to be optimized and its interaction with physiological systems remains to be further explored. The renin angiotensin system (RAS) plays a dual role in ischemia/reperfusion (I/R) injury. The interaction between RAS and PPC induced cardiac protection is however not clearly understood. We have recently demonstrated that angiotensin (1–7) via Mas receptor played a significant role in PPC mediated cardiac protection against I/R injury. Objective The objective of this study was to investigate the role of angiotensin converting enzyme (ACE)—chymase—angiotensin II (Ang II)—angiotensin receptor 1 (AT1) axes of RAS in PPC mediated cardiac protection. Methods Isolated rat hearts were subjected to I/R (control) or PPC in the presence or absence of Ang II, chymostatin (inhibitor of locally produced Ang II), ACE blocker (captopril) or AT1 antagonist (irbesartan). Hemodynamics data was computed digitally and infarct size was determined histologically using TTC staining and biochemically by measuring creatine kinase (CK) and lactate dehydrogenase levels. Results Cardiac hemodynamics were significantly (P<0.001) improved and infarct size and cardiac enzymes were significantly (P<0.001) reduced in hearts subjected to PPC relative to hearts subjected to I/R injury. Exogenous administration of Ang II did not affect I/R injury or PPC mediated protection. Nonetheless inhibition of endogenously synthesized Ang II protected against I/R induced cardiac damage yet did not block or augment the protective effects of PPC. The administration of AT1 antagonist did not alleviate I/R induced damage. Interestingly it abrogated PPC induced cardiac protection in isolated rat hearts. Finally, PPC induced protection and blockade of locally produced Ang II involved enhanced activation of ERK1/2 and Akt components of the reperfusion injury salvage kinase (RISK) pathway. Conclusions This study demonstrate a novel role of endogenously produced Ang II in mediating I/R injury and highlights the significance of AT1 signaling in PPC mediated cardiac protection in isolated rodents hearts ex vivo. The interaction between Ang II-AT1 and PPC appears to involve alterations in the activation state of ERK1/2 and Akt components of the RISK pathway.
Fawzi A. Babiker, Shaji Joseph, and Jasbir Juggi Springer Science and Business Media LLC
Fawzi A. Babiker, Shaji Joseph, and Jasbir S. Juggi S. Karger AG
Murry et al.  , devised the promising technique of preconditioning to salvage the myocardium from perfusion’s subsequent ischemic insult. This technique is used for repetitive brief episodes of ischemia before the occurrence of prolonged major ischemia that becomes lethal. While the technique is very promising as a new method of treatment for ischemic heart disease, its application in clinical practice has been arduous and highly risky. The difficulty is caused by a lack of the means to determine the time of occurrence of ischemia. Nevertheless, the technique can be applied in open heart surgery. At this level, repetitive inflating and deflating of the angioplasty balloon is easy to apply with almost no damage to the occluded blood vessel and can offer salvage from subsequent prolonged ischemia. Sometime later, Vinten-Johansen and his coworkers  introduced a technique similar to preconditioning with a greater probability of application to actual clinical practice. Postconditioning, the newly introduced technique, is the application of brief, repetitive ischemia and reperfusion. However, the innovation is that the procedure is performed after the ischemic insult and immediately at the beginning of reperfusion. This technique was found to be very efficient in providing protection to the ischemic myocardium and easily applied in clinical practice. An Early Intervention in the Treatment of Ischemic Heart Disease
J.S. Juggi, Farida Al-Awadi, Shaji Joseph, G. Telahoun, and A. Prahash Springer Science and Business Media LLC