Dexmedetomidine protects against lipid peroxidation and erythrocyte deformability alterations in experimental hepatic ischemia reperfusion injury

Background: Hepatic ischemia–reperfusion injury is a common clinical problem in hepatic surgery and transplantation. Several cellular and tissue structural and functional alterations are observed in such injury. The aim of this study was to evaluate the effect of dexmedetomidine on lipid peroxidation and erythrocyte deformability during ischemia–reperfusion injury in rats. Methods: Twenty-four Wistar Albino rats were randomly separated into three groups as control (C), ischemia–reperfusion injury (I/R) and dexmedetomidine group (I/R-D). Ischemia was induced with portal clampage for 45 min and reperfusion period was 45 min after declampage. Group I/R-D received dexmedetomidine 100 µg/kg i.p. 30 min before portal clampage. Serum malondialdehyde and superoxide dismutase activities to document lipid peroxidation and erythrocyte deformability index were investigated. Results: Serum superoxide dismutase and malondialdehyde activity levels were significantly higher and erythrocyte deformability index was decreased in hepatic ischemia–reperfusion group. However, these changes were observed to be prevented with dexmedetomidine treatment when given before portal clampage. Conclusion: These findings clearly indicate that erythrocyte deformability index is decreased in hepatic ischemia reperfusion injury and has a potential role to prevent these alterations. The protective effect of dexmedetomidine on hepatic I/R injury is also decreased lipid peroxidation. Further experimental and clinical investigations may clarify the molecular mechanisms and clinical significance of these findings

Consequences of social isolation in rats on their antioxidant defense system and erythrocyte deformability

Purpose: In this study, our purpose was to investigate effect of oxidative stress composing in isolated rats on erythrocyte deformability and antioxidant system, considering importance of mechanical, and biochemical properties of erythrocytes in efficiency of blood circulation Material and Methods: Fourty Sprague-Dawley rats were divided into two groups according to their ages; where one of them consisted of 2 months old rats and the other 12 months old rats. Then, randomly selected ten rats in each group were isolated separately in a cage and hold 12/12 hour light-dark cycle lasting 21 days. Blood samples were collected at the end of the 21st day, and superoxide dismutase (SOD), catalase (CAT) activities and malondialdehyde (MDA) levels were measured spectrophotometrically. Changes in plasma nitric oxide level were determined by Griess method depending on total nitrite-nitrate. In addition, relative filtration rate (RFR), relative filtration time (RFT) and relative resistance (Rrel) of the erythrocytes were calculated as the indexes of erythrocyte deformability. Results: The SOD and CAT levels were found significantly lower in both of young and adult isolated rats when compared to the young and adult control groups. The nitric oxide levels were also found significantly lower in the young and adult isolated rats when compared to their control groups. The peroxidation of the lipids were also decreased by social isolation, in the erythrocyte membrane of both young and adult isolated rats compared to the controls. The indexes of erythrocyte deformability, RFR was found significantly higher, whereas the RFT was significantly lower in young and adult isolated rats compared to the young and adult controls. However, the Rrel of the erythrocytes were not altered dramatically. Conclusion: As a consequence, our data reveals that the social isolation causes a lack of plasma nitric oxide levels in the socially isolated rats and probably due to this decrease in one of the major oxidants for the erythrocyte membrane results in the decreased lipid peroxidation. Furthermore, our results reveal that the social isolation stress causes alterations in the antioxidant defense system and these alteration results in the changes in erythrocyte deformability reflecting that some tissue perfusion problems can occur with long term and repeated loneliness and especially in the early stages of the life span

The influence of sevoflurane anesthesia on the rat red blood cell deformability

PubMed: 16899946Alterations in blood rheology under the influence of anesthesia have been observed and discussed among the responsible factors for the deterioration of tissue and organ perfusion related to anesthetic procedures. Sevoflurane is one of the volatil anesthetics which is being used very common in surgery. In this study, the effects of sevoflurane anesthesia were investigated in different age groups of rats. 22 male rats were used in the study and the rats were divided into two groups according to their age (young and old) comprising of two subgroups in each. First group was the young control (n = 5), the second was the young group treated with sevoflurane (n = 5), the third group was the old control (n = 7) and the last group was the old group treated with sevoflurane (n = 5). %2 of sevoflurane was applied to the rats with inhalation in a adjustable cage for one hour. The deformability indexes of the erythrocytes were measured by a laser diffractometer (Myrenne Rheodyne SSD). Deformability indexes of red blood cells were significantly decreased with sevoflurane in old rats (p = 0.028) whereas it had not any significant effect in young group compared with their controls. When we compared the young and old control groups, the deformability indexes were significantly higher in old ones (p < 0.001). However, there were not any significant difference between the old and the young sevoflurane applied groups. A volatil anesthetic agent sevoflurane has impaired the deformability of erythrocytes in old rats compared to their controls, whereas it had not any significant effect in young ones which may be due to the flexibility of the young erythrocytes leading them to tolerate to the environmental changes. These results reveal that the inhalation anesthetics like sevoflurane may cause more serious problems in the elder people and their hemodynamic parameters should be checked more seriously during the surgery. © 2006 - IOS Press and the authors. All rights reserved