Among these injuries, acidosis might start before the event that triggers cardiac arrest (such as a respiratory problem causing respiratory acidosis or infection causing metabolic acidosis), and the severity of the acidosis could become more severe once the circulation collapses (tissue ischemia/reperfusion injury, hypoxia, and free radicals all contribute to acidosis) [6, 9, 11, 12]

Among these injuries, acidosis might start before the event that triggers cardiac arrest (such as a respiratory problem causing respiratory acidosis or infection causing metabolic acidosis), and the severity of the acidosis could become more severe once the circulation collapses (tissue ischemia/reperfusion injury, hypoxia, and free radicals all contribute to acidosis) [6, 9, 11, 12]. The cells of vital organs have been demonstrated to be at risk of apoptosis at low pH levels [1315]. lower pH level (6. 5). More importantly, glutamine decreased cardiomyocyte apoptosis and increased these cells’ beating function at a low pH level. == 1 . Introduction == The survival rate for out-of-hospital cardiac arrest (OHCA) is very low [14]. Most sustained return of spontaneous circulation (ROSC) OHCA patients still die from post-cardiac arrest injuries [58]. These post-cardiac arrest injuries are critical PTGFRN and systemic reactions, including inflammatory overreactions, failed immune regulation, free-radical attack, and acidosis [2, 9, 10]. Among these injuries, acidosis might start before the event that triggers cardiac arrest (such as a respiratory problem causing respiratory acidosis or infection causing metabolic acidosis), and the severity of the acidosis could become more severe once the circulation collapses (tissue ischemia/reperfusion injury, hypoxia, and free radicals all contribute to acidosis) [6, 9, 11, 12]. The cells of vital organs have been demonstrated to be at risk of apoptosis at low pH levels [1315]. Furthermore, certain previous studies have reported that early, effective treatment for acidosis might decrease vital organ damage and further increase the survival rate [16, 17]. Therefore , sodium bicarbonate was initially recommended to AMG517 AMG517 treat post-cardiac arrest acidosis to restore the acid-base balance, and over the past 30 years, it was even suggested in standard resuscitation guidelines [18, 19]. Unfortunately, recent studies noted major side effects for sodium bicarbonate used for post-cardiac arrest acidosis (including inactivation of simultaneously administered catecholamines, reduction of systemic vascular resistance, hyperosmolality, extracellular alkalosis despite intracellular PCO2excess and hypernatremia), and it is no longer recommended in new resuscitation guidelines [18, 20, 21]. Therefore , effective and safe medication for treating post-cardiac arrest acidosis is still lacking. Glutamine, traditionally considered to be a nonessential amino acid, is now considered as conditionally essential following critical illness and sepsis [2224]. Recently, glutamine was demonstrated to increase ammoniagenesis and gluconeogenesis in the kidney. Excretion of the resulting ammonium ions increased the excretion of acid, whereas the combined pathways also contributed to the production of HCO3() ions [2529]. Therefore , we suspected that glutamine might be a potential medication for treating post-cardiac arrest acidosis. In the present study, we aimed to analyze whether early administration of glutamine could improve survival and protect cardiomyocytes from post-cardiac arrest acidosis using animal and cells AMG517 models. == 2 . Materials and Methods == == 2 . 1 . Ethics Statement == A total of 43 10-week-old male Wistar rats (301325 g in weight) obtained from BioLASCO Taiwan Co. Ltd. (Taipei, Taiwan) were used to analyze thein vivotreatment effect of glutamine in this study. Before the start of the study, all animals were fasted for 12 hours but given free access to water. The protocol was approved by the Committee on the Ethics of Animal Experiments of Changhua Christian Hospital (Permit Number: CCH-AE-104-005) and adhered to the recommendations of the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. == 2 . 2 . Setup of Animal Cardiac Arrest Model: Airways, Intravenous Line, and Measurements of Vital Signs == All rats were anesthetized with isoflurane via inhalation. After short-term inhalation, endotracheal tube (16-gauge polyethylene catheter mounted on a blunt-tipped needle) intubation was performed using the BioLITE Intubation Illumination System. The rats were AMG517 ventilated with controlled intermittent positive pressure ventilation (IPPV) (Hallowell.