Min Of Ischemia Research Articles

Acacetin Inhibits Oxidative Stress and Inflammation in Renal Ischemia-Reperfusion Injury

Background: Inflammation, oxidative stress, and cell death are major contributors to kidney injury following ischemia/reperfusion (I/R). Acacetin (ACA) is a natural flavonoid that many studies have shown can prevent I/R-induced damaging effects. Objectives: In the current attempt, we sought to search for the mechanisms through which ACA attenuates renal I/R. Methods: Male Balb/c mice were divided into four groups (n = 7): sham-operated group, I/R group, I/R treated with 50 mg/kg ACA group, and control group. Following 60 min ischemia, reperfusion was performed for 24 h. Administrations were done intraperitoneally daily for four consecutive days. Renal function was evaluated by measurement of creatinine. Changes in antioxidant capacity were evaluated by superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities. The expression of interleukin-1 beta (IL-1β), interleukin-6 (IL-6), interleukin-10 (IL-10), and interleukin-18 (IL-18), heme oxygenase-1 (Ho-1), nuclear factor (erythroid-derived 2)-like 2 (Nrf-2), and thioredoxin 1 (Trx1) was detected by real-time reverse transcription polymerase chain reaction (real-time RT-PCR). The levels of IL-10, tumor necrosis factor-alpha (TNF-α), and cyclooxygenase-2 (COX-2) were detected by enzyme-linked immunosorbent assay (ELISA) assay. Results: Creatinine level showed a decreased value after ACA treatment; however, declined SOD and GPx activities were elevated by ACA. The increased expression of IL-1β, IL-6, and IL-18 in the I/R group was declined in ACA-receiving mice. The expression levels of genes involved in anti-oxidative response Nrf-2, Ho-1, and Trx1 were decreased remarkably in the I/R group, and it reversed in ACA-treated mice. The secretion of IL-10 was elevated in the ACA-administrated group compared to untreated animals, while the COX-2 and TNF-α proteins were decreased following ACA treatment. Conclusions: These beneficial effects of ACA suggest that oxidative stress response participates in the protective effect of ACA against renal I/R.

Electrical auricular tragus stimulation induces release of circulating cardioprotective factors in healthy human volunteers.

Background: Vagal activation during remote ischemic conditioning (RIC) with subsequent release of cardioprotective factors from the spleen into the circulation reduces infarct size. These humoral cardioprotective factors can be transferred with plasma-dialysate from donors undergoing RIC to isolated recipient hearts where they reduce infarct size. Electrical auricular tragus stimulation (ATS) has been demonstrated to reduce the cardiac injury biomarker release and the frequency of ventricular arrhythmias and to improve contractile function in patients with acute myocardial infarction. Aim: To determine whether ATS, as RIC, induces release of cardioprotective factors into the circulation. Methods: Healthy volunteers (3 females, 7 males, 26±5 years) were randomized to receive ATS or RIC, respectively, with an interval of at least two weeks between protocols. ATS was induced by bipolar electrical rectangular pulses of 200μs width at a frequency of 30 Hz (Curamed TEN630, CURAmed, Shenzen Dongdixin Technology, Shenzhen, China). The amplitude (5.5 ± 0.81 mA) was set for each volunteer to not be perceived as uncomfortable over the total stimulation period. A microprocessor-controlled circuit periodically interrupted the stimulation signal after 5 s of stimulation for 5 s. ATS was continued over 30 min. RIC served as a reference to induce the release of cardioprotective factors by 3 x 5 min blood pressure cuff inflation at 200 mmHg on the left upper arm/ 5 min deflation. Venous blood samples were taken before and 60 min after ATS or RIC, respectively, and used to prepare plasma-dialysates (1:10 dialysis against buffer for 24 h, cut-off 12-14 kDa). Male Lewis rats were sacrificed and their hearts isolated and perfused at constant pressure with buffer. Plasma-dialysates from samples taken before and 60 min after ATS or RIC, respectively, were infused for 8 min followed by 2 min washout into rat hearts before global 30 min ischemia/ 120 min reperfusion. Infarct size was demarcated by triphenyl tetrazolium chloride staining and calculated as percent of ventricular mass. Results: With infusion of plasma-dialysate before ATS infarct size was 30.9±4.5% of ventricular mass and not different from that with infusion of plasma-dialysate before RIC (35.8±5.8%). Infusion of plasma-dialysate after ATS reduced infarct size to 18.3±3.9%. This cardioprotective effect was similar to that seen with infusion of plasma-dialysate after RIC (20.1±3.5%). Conclusion: ATS induces release of cardioprotective factors into the circulation of healthy volunteers. Plasma-dialysates after ATS or RIC, respectively, reduce myocardial infarct size by the same magnitude in ex vivo isolated perfused rat hearts with global ischemia/ reperfusion. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Is aryl hydrocarbon receptor antagonism after ischemia effective in alleviating acute hepatic ischemia-reperfusion injury in rats?

Aryl hydrocarbon receptors (AhRs) have been reported to be important mediators of ischemic injury in the brain. Furthermore, the pharmacological inhibition of AhR activation after ischemia has been shown to attenuate cerebral ischemia-reperfusion (IR) injury. Here, we investigated whether AhR antagonist administration after ischemia was also effective in ameliorating hepatic IR injury. A 70% partial hepatic IR (45-min ischemia and 24-h reperfusion) injury was induced in rats. We administered 6,2′,4′-trimethoxyflavone (TMF, 5 mg/kg) intraperitoneally 10 min after ischemia. Hepatic IR injury was observed using serum, magnetic resonance imaging-based liver function indices, and liver samples. TMF-treated rats showed significantly lower relative enhancement (RE) values and serum alanine aminotransferase (ALT) and aspartate aminotransferase levels than did untreated rats at 3 h after reperfusion. After 24 h of reperfusion, TMF-treated rats had significantly lower RE values, ΔT1 values, serum ALT levels, and necrotic area percentage than did untreated rats. The expression of the apoptosis-related proteins, Bax and cleaved caspase-3, was significantly lower in TMF-treated rats than in untreated rats. This study demonstrated that inhibition of AhR activation after ischemia was effective in ameliorating IR-induced liver injury in rats.

Remote Ischemic Conditioning Relieves Necrotizing Enterocolitis Through Regulation of Redox and Inflammation.

In neonates, necrotizing enterocolitis (NEC) is a serious condition involving oxidative stress and inflammation. Remote ischemic conditioning (RIC) is a potentially useful technique to protect distant organs from the damage induced by ischemia. RIC has been verified as effective to protect against NEC; however, its mechanism is unclear. This study aimed to assess the mechanism and efficacy of RIC to treat experimental NEC in mice. Between postnatal day (P) 5 and P9, we induced NEC in C57BL/6 mice and Grx1-/- mice. Intermittent occlusion of the blood flow to the right hind limb for 4 cycles of 5 min ischemia followed by 5 min reperfusion during NEC induction on P6 and P8 was used to apply RIC. We sacrificed the mice on p9 and evaluated oxidative stress, inflammatory cytokines, proliferation, apoptosis, and PI3K/Akt/mTOR signal pathway in mice ileal tissue. RIC decreased intestinal injury and prolonged survival in NEC pups. RIC significantly inhibited inflammatory, attenuated oxidative stress, reduced apoptosis, promoted proliferation, and activated PI3K/Akt/mTOR in vivo. RIC activates the PI3K/Akt/mTOR signaling pathway to control oxidative stress and inflammation. RIC might provide a new therapeutic strategy for NEC.

Warm Ischemia Induces Spatiotemporal Changes in Lysophosphatidylinositol That Affect Post-Reperfusion Injury in Normal and Steatotic Rat Livers.

Warm ischemia-reperfusion injury is a prognostic factor for hepatectomy and liver transplantation. However, its underlying molecular mechanisms are unknown. This study aimed to elucidate these mechanisms and identify the predictive markers of post-reperfusion injury. Rats with normal livers were subjected to 70% hepatic warm ischemia for 15, 30, or 90 min, while those with steatotic livers were subjected to 70% hepatic warm ischemia for only 30 min. The liver and blood were sampled at the end of ischemia and 1, 6, and 24 h after reperfusion. The serum alanine aminotransferase (ALT) activity, Suzuki injury scores, and lipid peroxidation (LPO) products were evaluated. The ALT activity and Suzuki scores increased with ischemic duration and peaked at 1 and 6 h after reperfusion, respectively. Steatotic livers subjected to 30 min ischemia and normal livers subjected to 90 min ischemia showed comparable injury. A similar trend was observed for LPO products. Imaging mass spectrometry of normal livers revealed an increase in lysophosphatidylinositol (LPI (18:0)) and a concomitant decrease in phosphatidylinositol (PI (18:0/20:4)) in Zone 1 (central venous region) with increasing ischemic duration; they returned to their basal values after reperfusion. Similar changes were observed in steatotic livers. Hepatic warm ischemia time-dependent acceleration of PI (18:0/20:4) to LPI (18:0) conversion occurs initially in Zone 1 and is more pronounced in fatty livers. Thus, the LPI (18:0)/PI (18:0/20:4) ratio is a potential predictor of post-reperfusion injury.

The key mediators involved in myocardial endoplasmic reticulum stress induced by ischaemia reperfusion injury in rats

Objective: Endoplasmic reticulum stress (ERS) occurs throughout the pathological process of myocardial ischaemia reperfusion injury (MIRI); however, the key mediators involved in the biological processes of ERS or that can influence the outcomes of ischaemia reperfusion injury (IRI) are unclear. To identify the differentially expressed genes (DEGs) encoding promising mediators in rat hearts in the context of MIRI, gene profiles were mined through transcriptome analysis. Methods: By searching the Gene Expression Omnibus (GEO) database, a suitable GEO dataset was identified in the context of MIRI with 24 h reperfusion after 45 min ischaemia in rats. DEGs were extracted and analysed with R studio, and the properties of those DEGs were elucidated by utilizing protein‒protein-interaction (PPI), Cytoscape, GO and KEGG bioinformatics techniques. The potential hub genes in the first cluster of the DEG dataset were retrieved and verified by basal experiments. Results: By searching the target dataset GSE122020, 1647 mRNAs, including 790 upregulated and 857 downregulated genes, were found in the datasets with criteria of | fold change ≥ 1.2 and p value <0.05. The upregulated and downregulated genes were primarily involved in the “positive regulation of cytokine production”, “regulation of inflammatory response” and “response to pheromone” biological processes. Most of them were mainly correlated with the MAPK, Ras and calcium signalling pathways. In particular, 15 DEGs were found to be involved in the ERS signalling pathways, including Bfar, Itpr1, Srpx, Hspa1b, Usp25, Jun, Casp12, Eif2ak2, Casp4, Trim25, Ifng, Atf3, Hspa1a, Ppp1r15a, and Creb3. Through analysis with the MCODE plugin in Cytoscape, six genes, Atf3, Ppp1r15a, Casp12, Eif2ak2, Ifng, and Hspa1a, were identified as hub genes by the K-means algorithm from Cluster 1. In the in vivo MIRI model, the six genes mentioned above exhibited significant mRNA overexpression in the left anterior descending coronary artery ligation (LAD) model in rats. Conclusions: Altogether, the present study identified six potential DEGs involved in ERS induced by MIRI, which could be therapeutic targets in dealing with IRI-related ERS.

Physiological ischemic training improves cardiac function through the attenuation of cardiomyocyte apoptosis and the activation of the vagus nerve in chronic heart failure.

This study investigated the functional outcomes of patients with chronic heart failure (CHF) after physiological ischemic training (PIT), identified the optimal PIT protocol, evaluated its cardioprotective effects and explored the underlying neural mechanisms. Patients with CHF were randomly divided into experimental group (n = 25, PIT intervention + regular treatment) and control group (n = 25, regular treatment). The outcomes included the left ventricular ejection fraction (LVEF), brain natriuretic peptide (BNP) and cardiopulmonary parameters. LVEF and cardiac biomarkers in CHF rats after various PIT treatments (different in intensity, frequency, and course of treatment) were measured to identify the optimal PIT protocol. The effect of PIT on cardiomyocyte programmed cell death was investigated by western blot, flow cytometry and fluorescent staining. The neural mechanism involved in PIT-induced cardioprotective effect was assessed by stimulation of the vagus nerve and muscarinic M2 receptor in CHF rats. LVEF and VO2max increased while BNP decreased in patients subjected to PIT. The optimal PIT protocol in CHF rats was composed of five cycles of 5 min ischemia followed by 5 min reperfusion on remote limbs for 8 weeks. LVEF and cardiac biomarker levels were significantly improved, and cardiomyocyte apoptosis was inhibited. However, these cardioprotective effects disappeared after subjecting CHF rats to vagotomy or muscarinic M2 receptor inhibition. PIT improved functional outcomes in CHF patients. The optimal PIT protocol required appropriate intensity, reasonable frequency, and adequate treatment course. Under these conditions, improvement of cardiac function in CHF was confirmed through cardiomyocyte apoptosis reduction and vagus nerve activation.

Hidden Pool of Cardiac Adenine Nucleotides That Controls Adenosine Production.

Myocardial ischemic adenosine production decreases in subsequent events that may blunt its protective functions. To test the relation between total or mitochondrial cardiac adenine nucleotide pool (TAN) on the energy status with adenosine production, Langendorff perfused rat hearts were subjected to three protocols: 1 min ischemia at 40 min, 10 min ischemia at 50 min, and 1 min ischemia at 85 min in Group I; additional infusion of adenosine (30 µM) for 15 min after 10 min ischemia in Group I-Ado, and 1 min ischemia at 40 and 85 min in the controls (Group No I). A 31P NMR and an HPLC were used for the analysis of nucleotide and catabolite concentrations in the heart and coronary effluent. Cardiac adenosine production in Group I measured after 1 min ischemia at 85 min decreased to less than 15% of that at 40 min in Group I, accompanied by a decrease in cardiac ATP and TAN to 65% of the initial results. Adenosine production at 85 min was restored to 45% of that at 40 min in Group I-Ado, accompanied by a rebound of ATP and TAN by 10% vs. Group I. Mitochondrial TAN and free AMP concentrations paralleled that of total cardiac TAN. Changes in energy equilibrium or mitochondrial function were minor. This study highlights that only a fraction of the cardiac adenine nucleotide pool is available for adenosine production, but further studies are necessary to clarify its nature.

Effects of Remote Ischemic Preconditioning on Postoperative Cognitive Dysfunction in Elderly Patients with Laparoscopic Cholecystectomy.

We hypothesized that remote ischemic preconditioning (RIPC) could improve postoperative cognitive dysfunction (POCD) in elderly patients following laparoscopic cholecystectomy (LC). Eighty-eight patients were randomly assigned to either the control or the RIPC group. The RIPC was applied on the right upper limb using a blood pressure cuff inflating 200 mmHg, consisting of 3 cycles of 5 min ischemia and 5 min reperfusion. Serum concentrations of Neuron-specific Enolase (NSE) and Brain-Derived Neurotrophic Factor (BDNF) were collected at one-day preoperative (T0), at the end of the operation (T4) and one-day postoperative (T5). Z score was tested at T0 and 3 days after the operation (T6). POCD was determined if there were two Z scores ≥1.96 at the same time or an average Z score ≥1.96. There was no significant difference in the Z score of each test between the two groups at T0 (P > 0.05). Notably, the duration of Stroop test C was significantly shorter in the RIPC group than that in the Control group at T6 (P = 0.01). POCD occurred in 1/44 (2.3%) patients in the RIPC group and 8/44 (18.2%) patients in the control group at T6 (P=0.035). In addition, serum NSE concentration was significantly decreased, but serum BDNF concentration was increased compared with the control group at T4 and T5 (P<0.001). RIPC could reduce the incidence of POCD in elderly patients after laparoscopic cholecystectomy.

Aortic ischemia-reperfusion injury and potency of fluoxetine.

Due to cross-clamping of the aorta during aortic aneurysm surgeries, ischemia-reperfusion (IR) develops, and it may cause damage to the aorta itself or even to remote organs by oxidative stress or inflammation. Fluoxetine (FLX) which might be used in the preoperative period for its tranquilizing effect also has antioxidant effects in short-term use. The purpose of our study is to examine whether FLX protects aorta tissue, against the damage caused by IR. Three groups of Wistar rats were formed randomly. 1) Control group (sham-operated), 2) IR group (60 min ischemia+120 min perfusion), and 3) FLX+IR group (FLX dose was 20 mg/kg for 3 days IP before IR). At the end of each procedure, aorta samples were collected, and oxidant-antioxidant, anti-inflammatory, and anti-apoptotic status of the aorta were evaluated. Histological examinations of the samples were provided. Levels of LOOH, MDA, ROS, TOS, MPO, TNFα, IL-1β, IL-6, NF-kB, MMP-9, caspase-9, 8-OHdG, NO, and HA were found to be significantly increased in the IR group compared with control (P<0.05) and SOD, GSH, TAS, and IL-10 levels were significantly lower (P<0.05). FLX significantly decreased LOOH, MDA, ROS, TOS, MPO, TNFα, IL-1β, IL-6, NF-kB, MMP-9, caspase-9, 8-OHdG, NO, and HA levels in the FLX+IR group compared with IR group (P<0.05) and increased IL-10, SOD, GSH, and TAS (P<0.05). FLX administration prevented the deterioration of aortic tissue damage. Our study is the first study that demonstrates FLX-mediated suppression of IR injury in the infrarenal abdominal aorta by antioxidant, anti-inflammatory, and anti-apoptotic properties.

A Single Bout of Remote Ischemic Preconditioning Suppresses Ischemia-Reperfusion Injury in Asian Obese Young Men.

Remote ischemic preconditioning (RIPC) has been shown to minimize subsequent ischemia-reperfusion injury (IRI), whereas obesity has been suggested to attenuate the efficacy of RIPC in animal models. The primary objective of this study was to investigate the effect of a single bout of RIPC on the vascular and autonomic response after IRI in young obese men. A total of 16 healthy young men (8 obese and 8 normal weight) underwent two experimental trials: RIPC (three cycles of 5 min ischemia at 180 mmHg + 5 min reperfusion on the left thigh) and SHAM (the same RIPC cycles at resting diastolic pressure) following IRI (20 min ischemia at 180 mmHg + 20 min reperfusion on the right thigh). Heart rate variability (HRV), blood pressure (SBP/DBP), and cutaneous blood flow (CBF) were measured between baseline, post-RIPC/SHAM, and post-IRI. The results showed that RIPC significantly improved the LF/HF ratio (p = 0.027), SBP (p = 0.047), MAP (p = 0.049), CBF (p = 0.001), cutaneous vascular conductance (p = 0.003), vascular resistance (p = 0.001), and sympathetic reactivity (SBP: p = 0.039; MAP: p = 0.084) after IRI. However, obesity neither exaggerated the degree of IRI nor attenuated the conditioning effects on the measured outcomes. In conclusion, a single bout of RIPC is an effective means of suppressing subsequent IRI and obesity, at least in Asian young adult men, does not significantly attenuate the efficacy of RIPC.

Effects of different remote ischemia perconditioning methods on cerebral infarct volume and neurological impairment in rats

Remote ischemic perconditioning (RIPerC) is a novel neuroprotective method against cerebral infarction that has shown efficacy in animal studies but has not been consistently neuroprotective in clinical trials. We focused on the temporal regulation of ischemia–reperfusion by RIPerC to establish an optimal method for RIPerC. Rats were assigned to four groups: 10 min ischemia, 5 min reperfusion; 10 min ischemia, 10 min reperfusion; 5 min ischemia, 10 min reperfusion; and no RIPerC. RIPerC interventions were performed during ischemic stroke, which was induced by a 60-min left middle cerebral artery occlusion. Infarct volume, sensorimotor function, neurological deficits, and cellular expressions of brain-derived neurotrophic factor (BDNF), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and caspase 3 were evaluated 48 h after the induction of ischemia. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) was also performed. RIPerC of 10 min ischemia/10 min reperfusion, and 5 min ischemia/10 min reperfusion decreased infarct volume, improved sensorimotor function, decreased Bax, caspase 3, and TUNEL-positive cells, and increased BDNF and Bcl-2 expressions. Our findings suggest RIPerC with a reperfusion time of approximately 10 min exerts its neuroprotective effects via an anti-apoptotic mechanism. This study provides important preliminary data to establish more effective RIPerC interventions.

Experimental study of cardioprotective effects of Cinnamomi Ramulus and Cinnamomi Cortex formula granules on myocardial ischemia/reperfusion injury in rats based on efficacy of "warming and coordinating heart Yang"

This study aimed to parallelly investigate the cardioprotective activity of Cinnamomi Ramulus formula granules(CRFG) and Cinnamomi Cortex formula granules(CCFG) against acute myocardial ischemia/reperfusion injury(MI/RI) and the underlying mechanism based on the efficacy of &quot;warming and coordinating the heart Yang&quot;. Ninety male SD rats were randomly divided into a sham group, a model group, CRFG low and high-dose(0.5 and 1.0 g·kg~(-1)) groups, and CCFG low and high-dose(0.5 and 1.0 g·kg~(-1)) groups, with 15 rats in each group. The sham group and the model group were given equal volumes of normal saline by gavage. Before modeling, the drug was given by gavage once a day for 7 consecutive days. One hour after the last administration, the MI/RI rat model was established by ligating the left anterior descending artery(LAD) for 30 min ischemia followed by 2 h reperfusion except the sham group. The sham group underwent the same procedures without LAD ligation. Heart function, cardiac infarct size, cardiac patho-logy, cardiomyocyte apoptosis, cardiac injury enzymes, and inflammatory cytokines were determined to assess the protective effects of CRFG and CCFG against MI/RI. The gene expression levels of nucleotide-binding oligomerization domain-like receptor family pyrin domain protein 3(NLRP3) inflammasome, apoptosis-associated speck-like protein containing a CARD(ASC), cysteinyl aspartate specific proteinase-1(caspase-1), Gasdermin-D(GSDMD), interleukin-1β(IL-1β), and interleukin-18(IL-18) were determined by real-time quantitative polymerase chain reaction(RT-PCR). The protein expression levels of NLRP3, caspase-1, GSDMD, and N-GSDMD were determined by Western blot. The results showed that both CRFG and CCFG pretreatments significantly improved cardiac function, decreased the cardiac infarct size, inhibited cardiomyocyte apoptosis, and reduced the content of lactic dehydrogenase(LDH), creatine kinase MB isoenzyme(CK-MB), aspartate transaminase(AST), and cardiac troponin Ⅰ(cTnⅠ). In addition, CRFG and CCFG pretreatments significantly decreased the levels of IL-1β, IL-6, and tumor necrosis factor-α(TNF-α) in serum. RT-PCR results showed that CRFG and CCFG pretreatment down-regulated the mRNA expression levels of NLRP3, caspase-1, ASC, and downstream pyroptosis-related effector substances including GSDMD, IL-18, and IL-1β in cardiac tissues. Western blot revealed that CRFG and CCFG pretreatments significantly decreased the protein expression levels of NLRP3, caspase-1, GSDMD, and N-GSDMD in cardiac tissues. In conclusion, CRFG and CCFG pretreatments have obvious cardioprotective effects on MI/RI in rats, and the under-lying mechanism may be related to the inhibition of NLRP3/caspase-1/GSDMD signaling pathway to reduce the cardiac inflammatory response.

Caryocar brasiliense peel ethanolic extract has neuroprotective potential and reduces the activation of ERK1/2 in the ischemia and reperfusion brain acute phase in the rat

Oxidative stress induced by ischemia and reperfusion (I/R) injury results in cell death by necrosis or apoptosis and triggers the activation of different intracellular pathways, such as mitogen-activated protein activated kinases. Pequi (Caryocar brasiliense) peel, residue of a fruit from Brazilian savannah-like vegetation, has phenolic compounds that have been demonstrated to have antioxidant effects in vitro. The present study aimed to evaluate the neuroprotective effects of C. brasiliense peel ethanolic extract (CBPE) against transient global I/R injury in the rat brain. Global ischemia for 5, 20, and 45 min followed by 2 h of reperfusion caused a significant time-dependent increase in the number of ischemic neurons (p ≤ 0.05); increased immunoreactivity of cleaved caspase-3 (CASP3); and activated extracellular signal-regulated kinase (ERK) 1/2. Pretreatment with CBPE (600 mg/kg, oral) or vitamin E (0.6 mg, oral) for 30 days showed significant protection against acute brain injury induced by 20 and 45 min or 5 min of ischemia, respectively, by reducing the cortical ischemic neuron count (p ≤ 0.05) and p-ERK1/2 immunoreactivity. In addition, active c-Jun N-terminal kinase (JNK) immunoreactivity was reduced in animals not subjected to ischemia. Therefore, we suggest an association between vitamin E and CBPE, which may generate a better neuroprotective response. Interestingly, mainly in the hippocampus and oligodendrocytes, high dose CBPE increase the number of isquemic neurons and of CASP3 immunoreactive cells in animals subjected or not to ischemia, which was not verified in the vitamin E group. Therefore, additional studies are recommended to verify the safety of the continuous use of CBPE.

Effect of reflex and mechanical decreases in skin perfusion on thermal- and agonist-induced eccrine sweating in humans.

In humans, skin blood flux (SkBF) and eccrine sweating are tightly coupled, suggesting common neural control and regulation. This study was designed to separate these two sympathetic nervous system end-organ responses via nonadrenergic SkBF-decreasing mechanical perturbations during heightened sudomotor drive. We induced sweating physiologically via whole body heat stress using a high-density tube-lined suit (protocol 1; 2 women, 4 men), and pharmacologically via forearm intradermal microdialysis of two steady-state doses of a cholinergic agonist, pilocarpine (protocol 2; 4 women, 3 men). During sweating induction, we decreased SkBF via three mechanical perturbations: arm and leg dependency to engage the cutaneous venoarteriolar response (CVAR), limb venous occlusion to engage the CVAR and decrease perfusion pressure, and limb arterial occlusion to cause ischemia. In protocol 1, heat stress increased arm cutaneous vascular conductance and forearm sweat rate (capacitance hygrometry). During heat stress, despite decreases in SkBF during each of the acute (3 min) mechanical perturbations, eccrine sweat rate was unaffected. During heat stress with extended (10 min) ischemia, sweat rate decreased. In protocol 2, both pilocarpine doses (ED50 and EMAX) increased SkBF and sweat rate. Each mechanical perturbation resulted in decreased SkBF but minimal changes in eccrine sweat rate. Taken together, these data indicate that a wide range of acute decreases in SkBF do not appear to proportionally decrease either physiologically- or pharmacologically induced eccrine sweating in peripheral skin. This preservation of evaporative cooling despite acutely decreased SkBF could have consequential impacts for heat storage and balance during changes in body posture, limb position, or blood flow restrictive conditions.

Trifecta and pentafecta outcomes following robot-assisted partial nephrectomy in a multi-institutional cohort of Indian patients.

The literature on studies reporting trifecta or pentafecta outcomes following robot-assisted partial nephrectomy (RAPN) in Indian patients is limited. The primary aim of this study was to report and evaluate the factors predicting trifecta and pentafecta outcomes following RAPN in Indian patients using the multicentric Vattikuti collective quality initiative (VCQI) database. From the VCQI database for patients who underwent RAPN, data for Indian patients were extracted and analyzed for factors predicting the achievement of trifecta and pentafecta following RAPN. Trifecta was defined as the absence of complications, negative surgical margins, and warm ischemia period shorter than 25 min or zero ischemia. Pentafecta covers all the trifecta criteria as well as >90% preservation of estimated glomerular filtration rate (eGFR) and no stage upgrade of chronic kidney disease at 12 months. In this study, among 614 patients, the trifecta was achieved in 374 patients (60.9%) and pentafecta was achieved in 24.2% of the patients. Patients who achieved trifecta had significantly higher mean age (54.1 vs. 51.0 years, P = 0.005), body mass index (BMI) (26.7 vs. 26.03 kg/m2, P = 0.022), and smaller tumor size (38.6 vs. 41.4 mm, P = 0.028). The preoperative eGFR (84.2 vs. 91.9 ml/min, P = 0.012) and renal nephrometry score (RNS) (6.96 vs. 7.87, P ≤ 0.0001) were significantly lower in the trifecta group. Comparing patients who achieved pentafecta to those who did not, we noted a statistically significant difference between the two groups for tumor size (36.1 vs. 41.5 mm, P = 0.017) and RNS (6.6 vs. 7.7, P = 0.0001). On multivariate analysis, BMI and RNS were associated with trifecta outcomes. Similarly, only RNS was identified as an independent predictor of pentafecta. RNS and BMI were independent predictors of the trifecta. At the same time, RNS was identified as an independent predictor of pentafecta following RAPN.

Participation of Leptin and Corticosterone in the Decrease in Infarct-Limiting Efficiency of Remote Postconditioning and in the Development of Arterial Hypertension in Metabolic Syndrome in Rats

We studied the effect of induced metabolic syndrome (MetS) on the effectiveness of the infarct-limiting effect of remote ischemic postconditioning (RP) in Wistar rats. The involvement of leptin and corticosterone in the formation of arterial hypertension (AH) and in reduction of the effectiveness of RP in MetS was also studied. MetS was induced by high-carbohydrate high-fat diet with replacement of drinking water with 20% fructose solution for 90 days. MetS simulation led to obesity, AH, impaired lipid and carbohydrate metabolism, hyperleptinemia, and moderate stress. All animals were subjected to 45-min coronary occlusion and 120-min reperfusion. In the RP groups, tourniquets were applied on the hind limbs in the area of the hip joint immediately after the end of ischemia (3 cycles consisting of 5-min ischemia and 5-min reperfusion). A direct correlation was found between the severity of AH in rats with MetS and the levels of corticosterone and leptin. In rats with MetS, the effectiveness of RP decreased: a direct correlation between the infarct size and serum content of leptin was revealed in rats with MetS+RP. Corticosterone seems to be one of the factors of AH development in rats with MetS.

PROTECTIVE EFFECT OF EPROSARTAN IN RENAL ISCHEMIA REPERFUSION INJURY BY REGULATING OXIDATIVE STRESS, INFLAMMATION, AND APOPTOTIC CASCADES IN A BILATERAL RAT MODEL.

The aim: To evaluate the potential protective effect of Eprosartan (ARB) in bilateral renal IRI in male rats. Materials and methods: 20 Sprague-Dawley rats divided into four groups. Sham group had surgery without IRI. Control group was subjected to 30 min ischemia and 2 hours of reperfusion. Vehicle group received 14 ml/kg (IP) injection of solvent mixture containing (10% DMSO, 40% PEG300, 5% Tween-80, and 45% normal saline) 30 minutes before clamping. Eprosartan-treated group with 30 mg/kg Eprosartan intraperitoneally 30 min before occlusion of renal pedicles followed by 30 minutes of ischemia and 2 hours of reperfusion. Serum BUN and Creatinine used to assess renal function. Renal tissue was used to measure the levels of TNF-α, IL-1β, IL-6, F2-isoprostane, and Caspase3 were measured by assessment of renal tissue. Histopathological examinations were conducted to detect parenchymal damage. Results: Mean serum levels of BUN and Creatinine as well as mean renal tissue levels of TNF-α, IL-1β, IL-6, F2-isoprostane, and Caspase3 were significantly increased in control and vehicle groups together with increase in histological damage score compared to sham group, whereas treatment of rats with Eprosartan resulted in significant reduction in mean serum levels of BUN and Creatinine and mean renal tissue levels of TNF-α, IL-1β, IL-6, F2-isoprostane, and Caspase3 and obvious reduction in tissue injury. Conclusions: This study demonstrates that Eprosartan pretreatment enhances kidney function by decreasing serum BUN and Creatinine, oxidative stress, cytokines, and apoptotic markers.

Repeated Episodes of Ischemia/Reperfusion Induce Heme-Oxygenase-1 (HO-1) and Anti-Inflammatory Responses and Protects against Chronic Kidney Disease

Preconditioning episodes of ischemia/reperfusion (IR) induce protection against acute kidney injury (AKI), however their long-term effect still unknown. We evaluated AKI to chronic kidney disease (CKD) transition, after three-mild or three-severe episodes of IR. AKI was induced by single bilateral IR (1IR), or three episodes of IR separated by 10-day intervals (3IR) of mild (20 min) or severe (45 min) ischemia. Sham-operated rats served as controls. During 9-months, the 1IR group (20 or 45 min) developed CKD evidenced by progressive proteinuria and renal fibrosis. In contrast, the long-term adverse effects of AKI were markedly ameliorated in the 3IR group. The acute response in 3IR, contrasted with the 1IR group, that was characterized by an increment in heme oxygenase-1 (HO-1) and an anti-inflammatory response mediated by a NFkB-p65 phosphorylation and IL-6 decrease, together with an increase in TGF-β, and IL-10 expression, as well as in M2-macrophages. In addition, three episodes of IR downregulated endoplasmic reticulum (ER) stress markers expression, CHOP and BiP. Thus, repeated episodes of IR with 10-day intervals induced long-term renal protection accompanied with HO-1 overexpression and M2-macrophages increase.

Abstract 11471: Engineered Bacterial Sodium Channel Gene Therapy Prevents Contractile Deficit and Reduces Ventricular Arrhythmias in a Non-Human Primate Model of Myocardial Infarction

Introduction: Current therapies for myocardial infarction (MI) and sudden cardiac death are limited. The ability to enhance amplitudes of sodium current and calcium transient in cardiomyocytes could improve electrical synchrony and contractions of infarcted heart tissue to both prevent arrhythmias and improve pumping function. We hypothesized that adeno-associated virus (AAV) delivery of prokaryotic sodium channel (BacNa v ) can improve electrical and contractile function of infarcted hearts. Methods: MI in non-human primates (NHPs) was induced by 60-min ischemia / reperfusion injury. Animals were randomized to sham surgery (n=6) or MI followed by intramyocardial injection of AAV-BacNa v (n=6) or AAV-GFP (n=6) into the infarct area and border zone. Left ventricular (LV) function was assessed by echocardiogram at baseline, 1- and 4-week post-MI. Spontaneous arrhythmias were tracked by a subcutaneously implanted loop recorder during the 4-week study period. Results: At 4 weeks post-MI, BacNa v and GFP expression were detected in all treated animals (Fig. 1). Compared to sham animals, GFP-treated animals showed lower LV ejection fraction (LVEF, 37.4±3.4% vs 58.2±1.2%, p&lt;0.0001) and increased LV end-systolic volume (3.8±0.57mL vs 2.1±0.25mL, p&lt;0.05). BacNa v -treated animals showed significant increase in LVEF compared to the GFP group (48.3±3.4% vs 37.4±3.4%, p&lt;0.05) and did not differ from the sham group. Compared to the GFP group, fewer BacNa v -treated animals displayed spontaneous arrhythmias (16.7% vs 100%, p&lt;0.05) and had less arrhythmia episodes per animal (0.17±0.17 vs 2.17±0.6, p&lt;0.01), while not differing in any measured electrophysiological parameters from the sham group. Conclusion: The AAV-mediated BacNa v expression in cardiomyocytes can alleviate cardiac contractile deficit and reduce ventricular arrhythmias in the setting of MI in an NHP model. BacNa v gene delivery may represent a promising therapeutic strategy for the treatment of MI.