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Biomedical subjects

A Pistelli

Publications and source records attributed to A Pistelli.

35 records · Page 2Linked to original sources
PubMed1991

Mast cells as a source of superoxide anions and nitric oxide-like factor: relevance to histamine release.

Rat serosal mast cells (MCs, 85-90% pure), obtained from peritoneal washing of Wistar albino rats, produced a significant amount of superoxide anions (O2.-) as measured by the increase in absorbance due to the reduction of ferricytochrome c; they were also able to generate a nitric oxide (NO)-like factor, as measured by two bioassay systems: i) inhibition of platelet aggregation and ii) stimulation of MCs guanylate cyclase. Incubation of MCs with human washed platelets resulted in an inhibition of thrombin-induced platelet aggregation which was proportional to cell number. The inhibitory activity of MCs was potentiated by substances which preserve NO (superoxide dismutase, SOD), and reversed by compounds which inactivate NO (oxyhaemoglobin, oxyHb) or which inhibit its synthesis (NG-monomethyl-L-arginine, MeArg). Mechanical stimulation of MCs produced a time-dependent increase in the levels of their cGMP but not cAMP; this increase was enhanced by E. coli lipopolysaccharide (LPS). NO generators such as sodium nitroprusside (NaNp) also augmented the levels of cGMP in MCs. NaNp inhibited in a dose-dependent manner the release of histamine evoked by compound 48/80 (0.5 microgram/ml), but not by the O2.--generating system (xanthine-xanthine oxidase), suggesting a bidirectional regulation of histamine release afforded by O2.- and NO.

Animals↗
PubMed1990

[Acute toxicity of trichloroethylene. Description of a case series at the Autonomous Service of Toxicology of Florence during the 1977-1988 period].

The authors report the number of acute trichloroethylene intoxications admitted to the Toxicological Unit of Florence University from January 1977 to December 1988. The identification of the solvent metabolic pathway allowed to clarify the pathogenesis of hepatorenal dysfunction observed during acute intoxications. Together with gastrointestinal decontamination and cardiac arrhythmia control we have studied the effect of drugs supposed to act as blockers of trichloroethylene metabolism or as inactivators of the hepatotoxic free radical metabolite 2-2(1)-3 trichloroxirane. The prognostic modification related to new therapeutic protocols is reported and discussed.

Acute Disease↗
PubMed1990

Histamine release from rat mast cells induced by metabolic activation of polyunsaturated fatty acids into free radicals.

Polyunsaturated fatty acids (PUFA: arachidonic and linoleic acid) release histamine from isolated purified rat serosal mast cells only in the presence of oxidizing systems such as phenobarbital-induced rat liver microsomes, prostaglandin-H-synthetase (PHS) or soybean lipoxygenase. The release of mast cell histamine by activated PUFA has a long time-course and the electron microscopical features are consistent with an exocytotic secretion in the case of arachidonic acid and cell lysis in the case of linoleic acid. The phenomenon is associated with a significant increase in malonyldialdehyde (MDA) and conjugated diene generation, suggesting a relationship between histamine release and membrane lipid peroxidation. The secretion of histamine was inhibited by anti-free radical interventions such as D-mannitol, reduced glutathione and alpha-tocopherol. Some cyclooxygenase and lipoxygenase inhibitors, cimetidine and carnitine derivatives, are differentially active in the inhibition of mast cell histamine release by activated arachidonic acid. These results suggest that free radical derivatives of PUFA, generated by metabolic activation, trigger mast cell histamine release.

Animals↗
PubMed1990

Histamine release by platelet aggregation.

Coincubation of rat serosal mast cells with human platelets leads to a significant release of histamine. which dose-dependently increases when platelet aggregation is induced by various concentrations of arachidonic acid. In turn, histamine enhances platelet aggregation induced by different agonists, this effect being mimicked by pyridyl-ethyl-amine (PEA), blocked by mepyramine and amplified by ranitidine. The data suggest the existence of a platelet-derived histamine releasing factor (PDHRF) and indicate the presence of platelet H1 and H2 receptors, capable of modulating platelet aggregation.

Animals↗
PubMed1990

Ischemia reperfusion injury and histamine release in isolated and perfused guinea-pig heart: pharmacological interventions.

Experiments were carried out to provide further information on the biochemical and morphological changes occurring in the guinea-pig heart after multiple ligature and reopening of the left anterior descending (LAD) coronary artery. In isolated perfused guinea-pig heart the reopening of LAD coronary artery leads to a release of histamine related to a loss of metachromasia by cardiac mast cells. The process is associated with malonyldialdehyde (MDA) production, cellular overload of calcium and ventricular arrhythmias which can be modulated by pharmacological interventions.

Animals↗
PubMed1989

Histamine release by free radicals: the relationship with the signal transduction system.

In isolated rat serosal mast cells exposed to free radical-generating systems, the release of histamine was associated with a significant increase in malonyldialdehyde (MDA) production suggesting a relationship between histamine release and membrane lipid peroxidation. Under these circumstances, an increase in cytosolic calcium was observed, uncoupled with any stimulation of inositol phospholipid (PtdIns) breakdown. The data suggest similarities between the release of histamine induced by calcium ionophores and by free radical-generating systems.

Animals↗
PubMed1989

Ischemia-reperfusion injury and histamine release in isolated guinea-pig heart: the role of free radicals.

Free radicals produced by the occlusion and opening of the left anterior descending coronary artery and/or by perfusion of isolated guinea-pig heart with FeCl3/ADP (10 microM/100 microM) induce a differential release of histamine and lactate dehydrogenase (LDH) in the perfusates with a preferential liberation of histamine in the reperfusion phase, associated with an increase of ventricular arrhythmias. The release of histamine has been correlated with malonyldialdehyde (MDA) production and tissue calcium content in left ventricular tissue. MDA increased during ischemia, while the calcium content increased when the tissue was reperfused. Under these conditions, N-t-butyl-alpha-phenylnitrone (BPN), a molecule capable of forming spin adducts with free radicals, and D-mannitol are active in preventing reperfusion-induced arrhythmias.

Animals↗
PubMed1989

Free radicals induce ischemia-reperfusion injury and histamine release in the isolated guinea pig heart.

Free radicals are produced by perfusion of isolated guinea pig heart with FeCl3/ADP (10 microM/100 microM) and/or occlusion and opening of the left anterior descending coronary artery. Cardiac histopathology was correlated with histamine and lactate dehydrogenase release and with malondialdehyde production. A differential release of histamine and lactate dehydrogenase in the perfusate was detected, showing a preferential liberation of histamine in the reperfusion phase. The increase in lipid peroxidation product in left ventricular tissues after left coronary artery occlusion was maximal at the end of ischemia.

Adenosine Diphosphate↗
PubMed1989

Prostaglandin H synthetase activates xenobiotics into free radicals: histamine release and biochemical characteristics.

In isolated rat serosal mast cells, studies with the fluorescent Ca2+ indicator, quin 2, and with [3H]-myoinositol to label endogenous polyphosphoinositides have established that an increase in cytosol Ca2+ levels was obligatory for histamine release by free radicals. No substantial breakdown of phosphatidylinositol and related polyphosphoinositides was associated with generation of the Ca2+ signal and histamine release, suggesting that the release of histamine by free radicals entails different pathways than the calcium-mobilizing receptors linked to polyphosphoinositides as second messengers.

Animals↗
PubMed1989

Pyrrolidone carboxylic acid in acute and chronic alcoholism. Preclinical and clinical studies.

2-Pyrrolidone-5-carboxylic acid (PCA) is a cyclic derivative of glutamic acid, physiologically present in mammalian tissues. We herein report preclinical pharmacology experiments showing that PCA releases GABA from the cerebral cortex of freely-moving guinea-pigs and displays anti-anxiety effects in a simple approach-avoidance conflict situation in the rat. In clinical pharmacology experiments, PCA significantly shortens the plasma half-life of ethanol during acute intoxication. In chronic alcoholics a treatment with PCA (2g/day per 30 days) significantly hastens the recovery to physiological values of plasma gamma-glutamyl transferase activity and of the urinary excretion of glucaric acid, which are considered suitable markers of the trend of the alcoholic disease. The evidence emerging from preclinical and clinical studies strongly suggests that, by combining central anxiolytic actions with the peripheral recovery of the antioxidant defense system in the liver, PCA should be further investigated as an interesting endogenous molecule possibly helpful in the therapy of alcoholism.

Alcoholic Intoxication↗
PubMed1988

Modulation of anaphylactic histamine release by calcium channel agonists and antagonists.

Calcium antagonists have been reported to exert protective effects in hypersensitivity reactions in man and animals. However, their effect on anaphylactic histamine release is highly variable and controversial. In the present paper we evaluate the effect of calcium entry blockers and BAY K 8644 on the response to specific antigen in isolated hearts taken from actively sensitized guinea-pigs and from isolated rat and guinea-pig mast cells, actively or passively sensitized. Verapamil, diltiazem, nifedipine and prenylamine dose-dependently decreased anaphylactic histamine release in isolated actively sensitized guinea-pig mast cells. BAY K 8644 was found to be ineffective. In isolated, passively sensitized rat mast cells, verapamil showed a highly significant inhibitory effect, while prenylamine (10(-4) M) was able to evoke a histamine releasing effect. In cardiac anaphylaxis verapamil, diltiazem, prenylamine, but not nifedipine, were active in reducing the release of histamine without modifying the antigen-induced arrhythmias and positive chronotropic and inotropic effects.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1988

Histamine release in acute coronary occlusion-reperfusion in isolated guinea-pig heart.

It has been shown that plasma histamine significantly increases during myocardial infarction in the dog. Histamine is also released when the isolated guinea-pig heart is reperfused after 30 minutes of low flow perfusion. The release of histamine and lactate dehydrogenase (LDH) after left anterior descending coronary artery ligation and release were investigated in the present study and related to the changes in electrocardiographic parameters and to a computer-aided analysis of left ventricular mast cell metachromasia. Spontaneous release of histamine was unchanged during ischemia and increased after the release of the ligature, while we observed a steady increase of LDH overflow. In parallel, a significant diminution of mast cell granule metachromasia was observed in left ventricular samples. The perfusion of the heart with FeCl3/ADP (10 microM/100 microM), a free radical-generating system, significantly enhanced both the basal and ischemic-reperfusion release of histamine, while perfusion with N-t-butyl-phenyl-nitrone (BPN/100 microM) a "spin-trapper" molecule, significantly decreased histamine and LDH release and the loss in metachromasia of left ventricular mast cells induced by reperfusion. Inhibitors of xanthine oxidase (allopurinol, 10 microM) and of calcium-activated proteases (leupeptin, 10 microM) modified the kinetics of histamine and LDH release.

Animals↗