scholarly journals Tolerance to acute ischemia in adult male and female spontaneously hypertensive rats

2007 ◽  
pp. 267-274 ◽  
Author(s):  
J Bešík ◽  
O Szarszoi ◽  
J Kuneš ◽  
I Netuka ◽  
J Malý ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Reperfusion Injury ◽  
Spontaneously Hypertensive Rats ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Left Ventricular ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Wky Rats ◽  
Developed Pressure

Clinical and experimental studies have repeatedly indicated that overloaded hearts have a higher vulnerability to ischemia/reperfusion injury. The aim of the present study was to answer the question whether the degree of tolerance to oxygen deprivation in hearts of spontaneously hypertensive rats (SHR) may be sex-dependent. For this purpose, adult SHR and their normotensive control Wistar Kyoto (WKY) rats were used. The isolated hearts were perfused according to Langendorff at constant pressure (proportionally adjusted to the blood pressure in vivo). Recovery of contractile parameters (left ventricular systolic, diastolic and developed pressure as well as the peak rate of developed pressure) was measured during reperfusion after 20 min of global no-flow ischemia in 5 min intervals. Mean arterial blood pressure was measured by direct puncture of carotid artery under light ether anesthesia in a separate group of animals. The degree of hypertension was comparable in both sexes of SHR. The recovery of contractile functions in SHR males and females was significantly lower than in WKY rats during the whole investigated period. There was no sex difference in the recovery of WKY animals; on the other hand, the recovery was significantly better in SHR females than in SHR males. It may be concluded that the hearts of female SHR are more resistant to ischemia/reperfusion injury as compared with male SHR. This fact could have important clinical implications for the treatment of cardiovascular disease in women.

Hyperbaric oxygenation protects the kidney against ischemia-reperfusion injury

2020 ◽  
pp. 21-30
Author(s):  
Milan Ivanov ◽  
◽  
Predrag Brkic ◽  
Una-Jovana Vajic ◽  
Nevena Mihailovic-Stanojevic ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reperfusion Injury ◽  
Kidney Function ◽  
Spontaneously Hypertensive Rats ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Renal Hemodynamics ◽  
Pure Oxygen ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive

Background: Acute kidney injury (AKI) as a consequence of ischemia is a common clinical event that can lead to unacceptably high morbidity and mortality. Hyperbaric oxygen (HBO2) preconditioning has been shown to prevent ischemia-reperfusion injury (IRI) in different tissues. Objectives: The aim of our study was to compare the effects of HBO2 preconditioning on renal hemodynamics, kidney function and oxidative stress in normotensive and spontaneously hypertensive rats that suffered kidney IRI. Methods: An experiment was performed on Wistar (normotensive) and spontaneously hypertensive rats (SHR). The animals were divided into the following experimental groups: sham-operated rats and rats with or without HBO2 preconditioning 24 hours before post-ischemic AKI induction. Treated rats were placed into experimental HBO2 chambers and exposed to pure oxygen twice a day for two consecutive days (2.026 bar of oxygen) for 60 minutes. AKI was performed the next morning. The right kidney was removed and the renal ischemia was performed by clamping the left renal artery for 45 minutes. Results: In this study, HBO2 preconditioning significantly improved disturbed renal hemodynamics, major markers of kidney function in plasma (creatinine, urea and phosphate) as well as antioxidant enzymes (superoxide dismutase and catalase) activities in erythrocytes after AKI induction. Also, HBO2 preconditioning decreased lipid peroxidation in plasma after ischemic AKI. Positive effects were observed in both strains of rats. Conclusions: Our results suggest that HBO2 treatment improves renal hemodynamic and kidney function and decreases oxidative stress of Wistar and SHR rats with an AKI episode. Furthermore, it also implies that pre-existing hypertension does not affect the beneficial effects of HBO2 preconditioning.

Changes of Blood Pressure Rhythm and Clock Protein Expression Levels in Spontaneously Hypertensive Rats After Ischemia-Reperfusion

2021 ◽  
Author(s):  
Jing Jin ◽  
Yumeng Liu ◽  
Jing Huang ◽  
Dong Zhang ◽  
Jian Ge ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Protein Expression ◽  
Circadian Clock ◽  
Spontaneously Hypertensive Rats ◽  
Ischemia Reperfusion ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Expression Levels ◽  
The Relationship ◽  
Clock Protein

Abstract Objective A variety of circadian patterns of blood pressure after ischemic stroke in patients with essential hypertension appear to be a potential risk of stroke recurrence, but the mechanism is still unclear. This study intends to reveal the changes in blood pressure rhythm and circadian clock protein expression levels in spontaneously hypertensive rats (SHR) after ischemia-reperfusion, and the relationship between the two. Methods Using the SHR middle cerebral artery occlusion experimental model, the systolic blood pressure was continuously monitored for 24 hours after the operation to observe the blood pressure rhythm. The rat tail vein blood was taken every 3h, and the serum CLOCK, BMAL1, PER1 and CRY1 protein expression levels were detected by Elisa. Pearson correlation analysis counted the relationship between SHR blood pressure rhythm and circadian clock protein fluctuation after ischemia-reperfusion. Results The proportion of abnormal blood pressure patterns in the SHR + tMCAO group was significantly higher than that in the SHR group, the serum CLOCK expression was relatively constant, and the circadian rhythm of BMAL1, PER1 and CRY1 protein expression changed significantly. Pearson analysis showed that PER1 protein level was negatively correlated with dipper (r = -0.565, P = 0.002) and extreme-dipper (r = -0.531, P = 0.001) blood pressure, and was significantly positively correlated with non-dipper blood pressure (r = 0.620, P < 0.001). Conclusion The rhythm pattern of blood pressure after ischemia-reperfusion in SHR is obviously disordered, and it is closely related to the regulation of Per1 gene.

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