Protection factors against free radical-induced ceroidogenesis.

The most important products of the combustion process are SO2, NOx, CO2 and the heavy metals. When these substances come into contact with the biotic components of the ecosystems they produce an oxidative damage by means of a free radical mechanism. One of the significant natural sources of these oxides and metals are the volcanic emissions that contribute, either locally or more diffusely, to enrich the atmosphere with these substances. The area of Campi Flegrei (Naples, Italy) is an experimental model fit for studying the contemporary effect of the aforesaid oxidative agents, because it is characterized by a continuous fumarolic activity, particularly in the area of the widest crater (Solfatara). We have made so two experiments utilizing rats and earthworms (Octolasium complanatum) to evaluate the following aspects in phylogenetically very different organisms: 1. the combined effect of the atmospheric pollutants, 2. the effect of the only heavy metals (Cu, Ni, Mn), 3. the protection action played by reduced glutathione in rats. The reduced glutathione being either a substrate of the glutathione proxidase or an oxyradicals scavenger, is one of the main protection agents against the above stress. Because many papers suggest that the mentioned atmospheric pollutants damage both animal and vegetable organisms by their oxidative properties, the reduced glutathione seems to be able to counteract efficaciously the damaging activity studied in terms of age pigments production.

Ceroidogenic effect of ionizing radiation.

The effect of the exposure of Torpedo marmorata to a single dose of 400 cGy of ionizing radiation and doses of 200 cGy/week for 4 weeks has been studied. The parameters measured were the TBA reactivity and lipofuscin production, a fluorescent pigment that is thought to derive from the reaction of malonaldehyde, a peroxide-degradation product, with free amino-groups. Acute irradiation was found to generate an increase of peroxidative damage in some tissues. This effect was inhibited by acetyl homocysteine-thiolactone, a drug that increases the activity of tissue superoxide dismutase. Chronic irradiation produces a severe increase in the generation of lipofuscin.

Effect of acetylhomocysteine thiolactone on nucleolar cytology and lipofuscinogenesis in electric lobe neurons.

Treatment with acetylhomocysteine thiolactone significantly reduces the cellular level of lipofuscin in neurons of the electric lobe of Torpedo marmorata. At the same time, this drug produces a 45% decrease in nucleolar volume in these neurons, reflecting decreased cellular synthetic activity.

Influence of environmental stress on lipofuscin production.

The Corollospora maritima, a marine ascomycete, has been used as an experimental model to investigate the possibility that age pigments can be considered indicators also of environmental stress. Synthetic sea water enriched with iron or copper has been inoculated in a broth culture of the fungus. After 5 days of incubation the mycetes were assayed for lipofuscin fluorescent pigment and malondialdehyde content. The presence in the culture medium of the heavy metal ions results in an increase of the lipofuscin and malondialdehyde production. The same evidence has been obtained with sea water samples collected at seven sites along the coast of the Gulf of Naples (Italy): the lipofuscin and malondialdehyde production increases proportionally with the copper and iron pollution in the sea water.

Effects of bonellin on lipids.

A comparative study was conducted on the ability of bonellin, the green pigment of Bonellia viridis, and hematoporphyrin to induce photoperoxidation of lipids in solutions and in erythrocyte ghosts. The inhibiting effect of two free radical scavangers, acetyl-homocysteine-thiolactone and meclofenoxate, indicates that bonellin-induced lipid peroxidation involves free radical production. The relation between bonellin and defence mechanism of Bonellia viridis is discussed.

Possible removal route of osmiophilic material (lipofuscin) from spinal ganglia of Torpedo marmorata.

The spinal ganglia of Torpedo marmorata have been studied in semithin and ultrathin sections with the view to study the formation and possible mode of removal of lipofuscin. This study suggests that osmiophilic bodies among them lipofuscin originate from degenerating mitochondria. These osmiophilic products concentrate at the neuronal cell border with the satellite cells. The satellite cells have long dense membranous processes which interdigitate, forming a compact myelin sheath but also loosely arranged membranes surrounded by vacuolated plasma. The perinuclear cytoplasmic portion of the satellite cell however contains a rich assemblage of cell organelles well provided for an active metabolism. In this active area which invaginates the neuronal cytoplasm, osmiophilic granules but smaller can be seen, similar to those in the neighbouring neuron. Similar granules are found in cells within the connective tissue space and in the capillary wall. Satellite cells appear not only to be ensheathing cells, providing a perineuronal myelin cover but also capable of removing intra-neuronal debris. It appears that these osmiophilic bodies are taken to the capillary wall by detached satellites or 'handed on' to phagocytes having penetrated between the ensheathing satellites. These cells could take the osmiophilic material to capillaries.

Morphological evaluation of the lipofuscinolytic effect of acetylhomocysteine thiolactone.

The acetylhomocysteine thiolactone, a free radical scavenger drug able to activate the superoxide dismutase, shows a lytic effect on neuronal lipofuscin. The study was performed in a nervous tissue particularly rich in lipofuscin, the electric lobe of Torpedo marmorata. It is shown that the drug induces the migration of pigment towards the blood vessels and glial cells which remove them.

Possible interrelations of acetyl-homocysteine-thiolactone in mechanisms of lipofuscinogenesis.

The administration of acetyl-homocysteine-thiolactone (cythiolone) to Torpedo marmorata inhibits the production of neuronal lipofuscin. The possible mechanism of this action has been investigated. A free radical scavenger effect of the drug has been demonstrated both in vivo and in vitro. Cythiolone is able to activate the enzyme superoxide dismutase, while no effect has been detected on catalase activity.

[The electrical discharge of Torpedo marmorata under normal conditions and during hypoxia and anoxia. I]. / La scarica eletrica di Torpedo marmorata in condizioni normali, di ipossia e di anossia. Prima nota.

The electric discharge of Torpedo M. can be considered as an index of the metabolic activity of the electric lobe of C.N.S. In groups of 10 Torpedoes the electric charge was measured: the mechanical stimulus was obtained by the falling of different weights from a determinate height. The experiment was then repeated in conditions of hypoxia: a fall of the electric discharge values was observed. The experiment was also carried out considering the time: after 14 hours the condition of anoxia occurred.

[Effects of dihydrodinoreburnameninol on the electrical discharge of Torpedo marmorata under normal conditions and during hypoxia and anoxia. I]. / Effetto del dihydrodinoreburnameninol sulla scarica elettrica di Torpedo marmorata in condizioni normali, di ipossia e di anossia. Prima nota.

The electric discharge of Torpedo M. can be considered as an index of the metabolic activity of the electric lobe of C.N.S. in groups of 10 torpedo the electric discharge was measured: the mechanical stimulus was obtained by the falling of different weights from a determinate height. Other 10 animals, to which the substance was administered, showed an increase of the electric discharge. The experiment was then repeated in conditions of hypoxia: a fall of the values of the electric discharge was observed. Finally the experiment was carried out considering the time: after 14 hours the condition of anoxia occurred.

[Protection furnished by dihydrodinoreburnameninol on the electrical activity of Torpedo marmorata kept in water polluted by copper. I]. / Protezione esercitata dal dihydrodinoreburnameninol sull'attivita' elettrica di Torpedo marmorata stabulate in condizioni di inquinamento da rame. Prima nota.

Studies carried out on neurons of Torpedo M. showed that copper creates an action of cellular damage inducing the synthesis of free radicals. Two groups of Torpedo, one for the control and the other one treated with dihydrodinoreburnameninol, were kept in sea water containing CuCl2. Then the measurement of the electric discharge was made: it was observed a clear dicrease in the Torpedo kept in conditions of pollution from copper, while the administration of dihydrodinoreburnameninol showed a protective action on the damaging effects.

Superoxide dismutase in the central nervous system of Torpedo marmorata.

In the central nervous system of Torpedo marmorata lipofuscin accumulates electively in the electric lobes. It has been found that the electric lobes have significantly lower superoxide dismutase activity than other areas of the central nervous system in animals of various ages and weights. These observations indicate that the lipoperoxidation action of the superoxide radicals or of their derived free radicals, due to superoxide dismutase deficit in these areas, might be related to lipofuscin accumulation.