[Malondialdehyde and nitric oxide behaviour in patients with myocardial infarction]

Exercise preconditioning-induced late phase of cardioprotection against exhaustive exercise: possible role of protein kinase C delta

The objective of this study was to investigate the late cardiac effect of exercise preconditioning (EP) on the exhaustive exercise-induced myocardial injury in rats and the role of protein kinase C (PKC) in EP. Rats were subjected to a run on the treadmill for four periods of 10 min each at 30 m/min with intervening periods of rest of 10 min as an EP protocol. The exhaustive exercise was performed 24 h after EP. PKC inhibitor chelerythrine (CHE) was injected before EP. The results showed that EP increased the running ability of rats, and alleviated the exhaustive exercise-induced injury in cardiomyocytes, but pretreatment with PKC inhibitor CHE did not abolish the late phase cardioprotection of EP. A significant increase of PKCδ, both at the protein level and the mRNA level in the left ventricular myocardium of rats, accompanied by its activated form (phosphorylated on Thr507, p-PKCδThr507) translocated to intercalated disks and was found in the late phase of EP. This circumstance was not attenuated by CHE. These results suggested that a high level of PKCδ might be involved in cardioprotection against myocardial damage, but if activated PKCδ at reperfusion took on a key role in cardioprotection was still an outstanding question.

Incremento de las concentraciones séricas de malondialdehído y glutatión reducido en pacientes con cardiopatía isquémica crónica estable

BACKGROUND AND OBJECTIVE

Cardiovascular diseases are associated with the ischemia/reperfusion phenomena and therefore to the oxidation/antioxidation balance. The aim of this study was to determine malondialdehyde, nitric oxide, glutathione, ascorbic and dehydroascorbic acid in patients with chronic ischemic heart disease.

PATIENTS AND METHOD

32 male patients, with chronic ischemic heart disease, between 40 and 60 years of age were studied. These individuals were divided in two groups: 16 with hypertension and 16 without hypertension. Both groups were compared with 31 healthy male subjects (control group).

RESULTS

Significant differences (p < 0.001) was observed in malondialdehyde between no-hypertension ischemic group: 5.3 (1.5) microM and the hypertension ischemic group: 4.8 (1.3) microM in contrast with the healthy group: 2.2 (0.5) microM. Hypertension ischemic group showed significant greater reduced glutation levels: 286.1 (31.4) microg/ml than control group 262.0 (38.8) microg/ml; p < 0.03 and no-hypertension ischemic group: 256.4 (41.5) microg/ml; p < 0.02. No significant difference in the rest of the parameters for all study groups.

CONCLUSIONS

Oxidation/antioxidation balance during chronic ischemic heart disease can be considered as a good metabolic ischemia indicator, that used in the monitoring and therapeutic evaluation could detect molecular changes that anticipate installation of tissue damage.

Increased Serum Malondialdehyde and Decreased Nitric Oxide Within 24 Hours of Thrombotic Stroke Onset

BACKGROUND AND PURPOSE

Ischemia/reperfusion generates free oxygen radicals, which react with the unsaturated lipids of biomembranes resulting in the generation products such as malondialdehyde. Malondialdehyde could be a sensor for tissue damage and reperfusion. Nitric oxide, released due to the early arrival of leukocytes in the brain parenchyma, could be a sensor for nonflow phenomenon. Thereby, the purpose of this research was to evaluate the behavior of malondialdehyde and nitric oxide within the 24 hours after the stroke onset.

METHODS

Fifteen patients up to an age of 49 years, admitted to the emergency of University Hospital and Chiquinquirá Hospital in Maracaibo, Venezuela, were examined by a neurologist and underwent 12-lead electrocardiograms and computed tomography for the diagnosis of thrombotic stroke. Serum malondialdehyde and nitric oxide were measured as thiobarbituric acid adducts and total nitrites. Data were collected within the 24 hours after the stroke onset.

RESULTS

Malondialdehyde for patients with stroke had a significant increase (P<0.001) when compared with healthy controls (47.9 +/- 7.1 vs. 1.7 +/- 0.2 micromol/L). Conversely, serum nitric oxide for patients with stroke had a significant decrease (P<0.001) when compared with the control group (14.5 +/- 1.4 vs. 41.3 +/- 3.7 micromol/L). The lowest values of malondialdehyde and the highest values of nitric oxide were observed in two patients, who died.

CONCLUSIONS

Serum levels of malondialdehyde increase, and serum levels of nitric oxide diminish within 24 hours after the onset of thrombotic stroke onset. This suggests that serum malondialdehyde level could be used as potentially reliable and sensitive marker for reperfusion, whereas nitric oxide levels could acts as potential biochemical sensor for nonreflow phenomenon.