Is midazolam effective as an antioxidant in preventing reperfusion injury in rat kidney?

Future Directions in Optimizing Anesthesia to Reduce Perioperative Acute Kidney Injury

BACKGROUND

Perioperative acute kidney injury (AKI) is common in surgical patients and is associated with high morbidity and mortality. There are currently few options for AKI prevention and treatment. Due to its complex pathophysiology, there is no efficient medication therapy to stop the onset of the injury or repair the damage already done. Certain anesthetics, however, have been demonstrated to affect the risk of perioperative AKI in some studies. The impact of anesthetics on renal function is particularly important as it is closely related to the prognosis of patients. Some anesthetics can induce anti-inflammatory, anti-necrotic, and anti-apoptotic effects. Propofol, sevoflurane, and dexmedetomidine are a few examples of anesthetics that have protective association with AKI in the perioperative period.

SUMMARY

In this study, we reviewed the clinical characteristics, risk factors, and pathogenesis of AKI. Subsequently, the protective effects of various anesthetic agents against perioperative AKI and the latest research are introduced.

KEY MESSAGE

This work demonstrates that a thorough understanding of the reciprocal effects of anesthetic drugs and AKI is crucial for safe perioperative care and prognosis of patients. However, more complete mechanisms and pathophysiological processes still need to be further studied.

Direct assessment of the antioxidant properties of midazolam by electron spin resonance spectroscopy

Some antioxidant anesthetics directly inhibit lipid peroxidation mediated via the generation of reactive oxygen species (ROS). To date, the scavenging effects of midazolam on ROS have not been directly assessed. We investigated the inhibitory effect of midazolam on ROS [hydroxyl radical (HO(·)) and superoxide (O (2) (·-) )] by in vitro X-band electron spin resonance with the spin-trapping agent 5,5-dimethyl-1-pyrroline-N-oxide. Our results indicated that HO(·) and O (2) (·-) were not affected by midazolam at clinically relevant concentrations, but were directly scavenged by midazolam at high concentrations (i.e., >4.6 and >1.5 mM, respectively).

Cadmium intoxication of pregnant rats and fetuses: interactions of copper supplementation

BACKGROUND AND AIMS

Cadmium (Cd) is an industrial and environmental pollutant that was shown to be involved in the development of some diseases. Due to high amounts of Cd in cigarettes, smokers and passive smokers are exposed to high amount of Cd. We aimed to determine whether Copper (Cu) supplementation would have a protective effect against Cd intoxication in pregnant rats and their fetuses.

METHODS

Experiments were performed on 27 adult female Wistar albino rats divided into three experimental groups. CdCl(2), CdCl(2) plus CuSO(4) and only drinking water was given to different groups for 21 days. We measured cadmium (Cd), malondialdehyde (MDA), reduced glutathione (GSH), myeloperoxidase (MPO), superoxide dismutase (SOD) and catalase (CAT) levels in dams' liver, dams' kidney, fetus liver, fetus kidney, and placenta of rats.

RESULTS

In all tissues of Cd and Cd + Cu-treated groups, Cd levels were found to be increased significantly when compared to control group. MDA levels and MPO activities were significantly increased whereas GSH levels, activities of SOD and CAT were decreased in Cd groups when compared to control group. Cu supplementation significantly prevented the increment in MDA levels and brought MPO activities back to control levels or below. Cd-induced reductions in GSH levels and SOD activities were also prevented by Cu supplementation. An increase of CAT activity after Cu supplementation was enough to revert to the control levels in some tissues.

CONCLUSIONS

Our findings suggest that Cu supplementation may have a protective effect against the Cd-induced oxidative stress in liver, kidney and placental tissues of pregnant rats and fetuses.

Oxidative stress parameters in patients with slow coronary flow

INTRODUCTION

We investigated the probable role of free-radical damage in the pathogenesis of slow coronary flow (SCF) by using oxidative stress parameters.

METHODS

Sixty-four patients with angiographically proven SCF and 63 patients with normal coronary flow (NCF) pattern with similar risk profiles were enrolled in this study. We measured erythrocyte superoxide dismutase (SOD), reduced glutathione (GSH), serum malondialdehyde (MDA), catalase and myeloperoxidase (MPO) levels in all subjects.

RESULTS

There were statistically significant differences in the levels of erythrocyte SOD, GSH and serum MDA between the 2 groups. Serum MDA (P = 0.003) and erythrocyte SOD levels (P = 0.0001) were increased in the SCF group. The level of erythrocyte GSH (P = 0.010) was lower in patients with SCF. There were no differences between the groups' serum catalase (P = 0.682) and MPO levels (P = 0.070).

CONCLUSION

Our data showed that in patients with SCF, serum MDA and erythrocyte SOD levels were increased while erythrocyte GSH levels were decreased significantly, compared with NCF patients. These results indicate that free-radical damage may play a role in the pathogenesis of SCF.

Neuroprotective effects of L-carnitine and vitamin E alone or in combination against ischemia-reperfusion injury in rats

BACKGROUND

Neurological injury because of transient cerebral ischemia is a potential complication of cardiovascular surgery. In this study, the neuroprotective effects of L-carnitine, vitamin E, and the combination of these agents on ischemia/reperfusion (I/R) injury were determined in a rat model of transient global cerebral I/R.

METHODS

Rats were pretreated with L-carnitine (100 mg/kg, i.v.) and vitamin E (50 mg/kg, i. v.), alone or in combination and then subjected to cerebral I/R induced by a four-vessel-occlusion technique for a duration of 15 min followed by 15 min of reperfusion. Malondialdehyde (MDA) levels, superoxide dismutase (SOD) activity, and glutathione (GSH) levels were measured in the cerebral tissues. Histopathological examinations were also carried out under light and electron microscopy.

RESULTS

The results showed that I/R elevated MDA levels, which were accompanied by a reduction in SOD activities and GSH levels. Surviving neurons was markedly decreased in CA1 and CA3 subfield of hippocampus in I/R animals. L-carnitine, vitamin E, and their combination restored MDA levels and SOD activities, with a tendency to increase surviving neurons in CA1 and CA3 subfield. Combined treatment of L-carnitine and vitamin E had better GSH levels than individual treatment of these agents.

CONCLUSIONS

The results suggest that L-carnitine has a potent neuroprotective effect against cerebral-I/R-induced injury in rat brain that is comparable to that of vitamin E. However, the combined use of L-carnitine and vitamin E does not further protect from neuronal injury, although it provides an increase in GSH levels.