Luigi Zecca

The effect of alternating magnetic fields on experimental inflammation in the rat

Abstract There is a large interest in the use of pulsed electromagnetic fields in inflammatory pathologies. The anti-inflammatory activity of a pulsed magnetic field has been tested in rats. As experimental models, the carragenin acute inflammation and chronic adjuvant arthritis were applied. A significant decrease of edema volume was noted in the acute model. On the contrary, no changes in inflammation rate were observed in the chronic model, even if a significant improvement of performance was shown.

Purine involvement in morphine antinociception.

1 The effects of a series of adenosine derivatives on morphine antinoceptive effect were investigated in rats by the ‘tail‐flick’ method. 2 2‐Chloroadenosine (CADO) and L‐N6‐phenylisopropyladenosine (L‐PIA), given intraperitoneally, caused decreased morphine antinociception. 3 Intracerebroventricular injections of CADO, L‐PIA and 5′‐N‐ethylcarboxamide adenosine (NECA), but not of 2′‐deoxyadenosine, antagonized morphine antinociception. 4 The effects of both central and peripheral injections of CADO and L‐PIA on morphine antinociception were partially reversed by caffeine. 5 Intracerebroventricular injection of dibutyryl‐cyclic 3′,5′ adenosine monophosphate (db cyclic AMP) had no effect on morphine antinociception. 6 These data indicate that adenosine plays a role in morphine‐induced antinociception. The results are discussed in terms of postulated effects of adenosine derivatives on adenylate cyclase.

Effects of 2-Chloroadenosine on hippocampal GABA content and turnover

The effects of 2-Chloroadenosme (CADO), a stable analog of adenosine, on GABA turnover rate and GABA content in the rat hippocampusin vivo have been studied. The intracerebroventricular injection of CADO reduced the GABA turnover rate in the hippocampus, as estimated from the rate of GABA accumulation after inhibition of GABA transaminase (GABAT) by aminooxyacetic acid (AOAA). The effect of CADO on AOAA-induced accumulation of GABA in the hippocampus was blocked by the intraperitoneal injection of the adenosine receptor antagonist caffeine. Furthermore, CADO at the dose of 5Μg per ventricle produced a significant decrease in GABA content in the hippocampus. Our results support the hypothesis that adenosine exerts inhibitory effects on GABAergic circuits in the hippocampus.

Synthesis and biodistribution of an 123I labelled flunitrazepam derivative: a potential in vivo tracer for benzodiazepine receptors.

A method for the synthesis of no-carrier-added of 7-[123I]iodo-1,3-dihydro-5-(2-fluorophenyl)-1-methyl-2H-1,4- benzodiazepine-2-one with a radiochemical yield of 25-30% has been developed. This benzodiazepine was prepared by reaction of [123I]iodide with the corresponding piperidyltriazene in acid medium and the reaction has been optimized for solvent, time and temperature. The triazene was synthesized by reduction of flunitrazepam to the amine, diazotisation and coupling with piperidine. Biodistribution studies of this radioligand in rats showed a maximum brain uptake of 0.35% of the injected dose at 15 min, which decline to 0.02% at 120 min.

Toxicological and teratological studies in rats after exposure to pulsed magnetic fields

Abstract The risk effects of low-intensity pulsed magnetic fields on rat fetal development and on the adult rat were examined. Pregnant female rats were exposed daily to the field (50 Hz and 58 G) during organogenesis. Fetuses were tested for number, size, weight and malformations. Adult rats (150–185 g) were exposed daily for 28 days to the field, then sacrificed. General conditions, behaviour and increase in weight were observed. Furthermore, hematological, hematochemical and urine determinations were carried out. The main organs were weighed and evaluated histologically. No significant differences were noted in both experiments. These results may suggest that the effects of low-intensity pulsed magnetic fields are not detectable under the conditions used here.