61 research outputs found
Morphine or its withdrawal affects plasma malondialdehyde, vitamin E levels and absence or presence of abstinence signs in rats
No full textObjectives: Various experimental observations show that morphine treatment generates reactive oxygen species, and that its discontinuation leads to signs of withdrawal. We therefore investigated plasma malondialdehyde and vitamin E levels under both conditions to verify the occurrence of any alterations in oxidative metabolism, and whether these are associated with behavioural changes. Methods: We investigated the effects of morphine or morphine plus naloxone on plasma malondialdehyde, vitamin E levels and withdrawal signs such as jumping, wet dog shakes and faecal excretion in rats. Furthermore, isopropylnoradrenaline was injected in rabbits to verify its effects on plasma malondialdehyde levels. Key findings: Morphine treatment increased free malondialdehyde and decreased vitamin E levels. The elevation in malondialdehyde levels were exacerbated by the abrupt removal of morphine by naloxone, which also led to the appearance of withdrawal signs. The increased malondialdehyde values can be attributed to the interactions of reactive oxygen species with unsaturated fatty acids, and the lowered levels of vitamin E to its interactions with reactive oxygen species. Conclusions: A connection seems to exist between altered peroxide status and withdrawal signs in abstinent animals
Critical study of preanalitical and analytical phases of adenine and pyridine nucleotide assay in human whole blood
No full textIntracellular redox and energetic status play a crucial role in cardiovascular diseases and metabolic disorders. The physiological
status of reducing agents, such as NADPH and NADH, and of high-energy molecules, such as ATP, is required for antioxidant system
activity. For these reasons, an accurate measurement of adenine and pyridine nucleotides is fundamental. In this study we examined
the preanalytical phase of reduced pyridine (RPN) and adenine and oxidized pyridine (AOPN) nucleotide assay in human
whole blood. DiVerent experimental conditions were applied to RPN alkaline and AOPN acid extracts to Wnd the best analytical performance.
Our results show that a good RPN and AOPN linearity (r from 0.994 to 0.999), recovery (near to 100%), and precision
(coeYcient of variation 05%) were obtained when supernatant from acid and ultraWltrate from alkaline extracts were neutralized,
frozen, and thawed just before HPLC injection. Since NADH decays rapidly at ¡80 °C, RPN levels must be assayed within 72 h
while AOPN can be stored for 1 month at the same temperature. An accurate and quantitative method for nucleotide determination
can be obtained by applying the preanalytical conditions proposed in this study
Screening of homocysteine from newborn blood spots by high-performance liquid chromatography with coulometric array detection
No full textHomocystinuria, due to a deficiency of cystationine-beta-synthase, refers to the rare inborn error of the metabolism of homocysteine. The identification and prompt treatment of homocystinuria during the neonatal period can prevent or greatly reduce the severity of the clinical consequences. We report a new method for homocystinuria diagnosis from dried blood spots on newborn screening cards, based on high-performance liquid chromatography with electrochemical coulometric array detection. This method shows an excellent linearity (y=10.36x+0.04; r=0.999), precision (RSDs ranged from 2.7 to 5.8%), recovery (87%) and appears to be a cost-effective approach, being simple, rapid, sensitive and cheap
Homocysteine (HCY) and malondialdehyde (MDA) levels during hemopoietic stem cell transplantation (HSCT)
No full textIsoproterenol-induced myocardial infarction in rabbits. Protection by propranolol or labetalol: a proposed non-invasive procedure
No full textMyocardial infarction is usually induced in small animals by means of invasive techniques based on mechanical coronary obstruction. As it has been reported that isoproterenol can cause ischemic myocardial alterations, lipid peroxide generation and procoagulant activity, we administered it to rabbits in order to induce a non-invasive myocardial infarction associated with above mentioned cardiovascular risk factors. Considerable ischemic alterations were observed in the animals treated with isoproterenol, including areas of myocardial necrosis, contraction band necrosis, increased plasma levels of cardiac necrosis markers (c-troponin I and myoglobin), and electrocardiographic modifications (ST segment changes and T wave inversion). The myocardial infarction was attributed to the inotropic activity of isoproterenol leading to intracellular calcium overload. The cardiac necrosis phenomena appear to be associated with isoproterenol-induced lipid peroxide generation (as shown by the decrease in plasma Vitamin E levels) and increased procoagulant activity (a shortened PTT). As this model of myocardial damage is based on the use of beta-stimulatory isoproterenol, the beta-blockers propranolol and labetalol were administered to isoproterenol-treated animals. Pretreatment with propranolol or labetalol counteracted the appearance of the myocardial histological alterations and the associated ECG and biochemical lesions. This protective activity was attributed to the beta-blockade. The results of this study demonstrate that myocardial infarction can be induced chemically and non-invasively in small laboratory animals. The procedure is proposed for the study of early ischemic myocardial lesions and the screening of drugs (such as beta-blockers) that can prevent myocardial necrosis damage and the associated risk factor
Il test di aderenza batterica nello studio dell'infertilità maschile da infezione del tratto genitale
No full textMetabolismo dell’omocisteina e pannello lipidico in forti fumatori sani : influenza del sesso
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