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Biomedical subjects

M Trabucchi

Publications and source records attributed to M Trabucchi.

At least 343 records · Page 19Linked to original sources
PubMed1980

Acute and chronic ethanol administration on specific 3H-GABA binding in different rat brain areas.

Acute ethanol treatment produces a significant decrease of specific 3H-GABA binding in cerebellum while no changes were detectable in other brain areas. Scatchard analysis shows a decrease in receptor affinity but not in the number of GABA binding sites. On the other hand, chronic administration of ethanol selectively increases specific 3H-GABA binding in the striatum. Kinetic analysis of these data shows that ethanol chronic administration produces a significant increase in the number of GABA binding sites. These data may be useful for the understanding of clinical pictures following acute and chronic ethanol intoxication.

Animals↗
PubMed1980

Impairment of brain neurotransmitter receptors in aged rats.

Dopamine and gamma-aminobutyric acid (GABA) receptor functions have been measured in various brain areas of aged rats. [3H] Spiroperidol binding is decreased in various dopaminergic brain areas, particularly in striatum and tuberculum olfactorium. In striatum the number of binding sites for [3H] spiroperidol is similar in both groups of animals, while the affinity is reduced in senescent rats. Moreover, in the pituitary a 50% increase of [3H] spiroperidol binding was detected in the group of senescent animals. On the other hand, [3H] GABA binding is significantly decreased in substantia nigra and hypothalamus of aged rats, while it is unmodified in cerebral cortex, cerebellum, striatum and nucleus accumbens.

Aging↗
PubMed1980

Effect of chronic lead treatment on GABA-ergic receptor function in rat brain.

The effect of chronic lead treatment on brain gamma-amino-butyric acid (GABA)-ergic function has been studied in an attempt to correlate the clinical aspects of the chronic exposure to the metal with specific neurochemical alterations. [3H]GABA-specific binding and cyclic guanosine monophosphate (GMP) content have been measured in various rat brain areas and have been found to be increased in cerebellum and decreased in the striatum of rats after chronic lead treatment. The changes found in the GABA-ergic neurons were correlated with the different levels of lead exposure in rats. Our results indicated that lead selectively affects GABA-ergic function in various rat brain areas, inducing effects which are dose-dependent.

Animals↗
PubMed1980

Ethanol effects on dopaminergic function: modulation by the endogenous opioid system.

Different behavioral and biochemical data suggest that ethanol has different effects on central dopaminergic transmission in rat and mouse. We found that ethanol induces an increase of striatal dopamine turnover which does not persist after chronic drinking. Following chronic ethanol treatment, we observed the development of supersensitivity of the striatal dopamine (DA) recognition sites, in terms of an enhanced affinity. We investigated various experimental models to clarify the existence of an enkephalinergic modulation of ethanol effects on the dopaminergic system. We found that in the rat, a pretreatment with naloxone abolishes the striatal DA turnover increase observed after ethanol. DBA 2J mice, which differ from C57 BL/6J and Swiss Albino, by genetically lacking enkephalinergic modulation on dopaminergic activity in the striatum, do not show any change of DA metabolism after acute ethanol. In the rat retina, where we hypothesized a less operant regulation of dopaminergic activity by enkephalins, tolerance does not develop after chronic drinking to the increase in DA turnover as it did in striatum. Our results confirm the importance of the endogenous opioid system in the regulation of the ethanol induced neurochemical and behavioral effects.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1980

Dopamine metabolism and receptor function after acute and chronic ethanol.

Acute ethanol treatment in rats elicits a selective increase in dihydroxyphenylacetic acid (DOPAC) content in striatum. In contrast, striatal DOPAC concentration does not differ from normal values after chronic ethanol treatment. Chronic administration of ethanol however causes a selective increase of specific [3H]spiroperidol binding and met-enkephalin content in the striatum. Kinetic analysis of [3H]spiroperidol binding data shows that after chronic ethanol treatment there is a significant increase in the affinity constant rather than in the number of binding sites for the ligand. Our results support the hypothesis that dopaminergic mechanisms at both pre- and postsynaptic level may be involved in the mediation of some of the central effects observed after ethanol consumption.

Animals↗
PubMed1979

Long-term effect of ovariectomy on dopamine-stimulated adenylate cyclase in rat striatum and nucleus accumbens.

The long-term effects on dopamine-sensitive adenylate cyclase of deprivation of gonadal steroids resulting from ovariectomy were studied in extrahypothalamic areas of the brain, i.e. corpus striatum and nucleus accumbens. The results obtained show that in both central nervous system areas dopamine- and apomorphine-stimulated adenylate cyclase were significantly reduced, suggesting that the function of dopamine receptors in these areas was depressed.

Adenylyl Cyclases↗
PubMed1979

Hemiparkinsonism. A human model for studying dopaminergic supersensitivity.

The observation of a patient suffering from a parkinsonian syndrome, almost entirely expressed on the right side, and "on-off" attacks with rotatory movement of the trunk, led us to consider that the rotational model of animals may be reproduced in man. The symptoms presented by our patient may reflect a predominant degeneration in the nigrostriatal pathway of the left side. We suggest that his torsion behavior is due to hypersensitivity phenomenon of the dopaminergic receptors on this side.

Animals↗
PubMed1979

Interaction of sulfpride and ergot derivatives on rat brain DOPAC concentration and prolactin secretion in vivo.

Sulpiride, which differs from classical neuroleptics by not producing major extrapyramidal side effects, is a potent antiemetic agent and stimulates prolactin secretion in both laboratory animals and man. In parallel it increases dopamine synthesis in both striatum and nucleus accumbens. Bromocriptine and metergoline are two effective agents in suppressing prolactin release and postulated to stimulate dopamine receptors. The interactions of these two ergot derivatives with sulpiride have been investigated on prolactin release and on striatal and limbic DOPAC accumulation. Bromocriptine at all doses tested was able to suppress the increased in vivo prolactin secretion observed after sulpiride administration. Metergoline antagonized the sulpiride-induced prolactin increase only at low doses; on the contrary higher doses potentiated it. High concentrations of bromocriptine suppressed the sulpiride-induced increased of DOPAC levels in striatum and n. accumbens, while metergoline potentiated the sulpiride-induced accumulation of brain DOPAC.

3,4-Dihydroxyphenylacetic Acid↗