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Biomedical subjects

E Stefanini

Publications and source records attributed to E Stefanini.

44 records · Page 3Linked to original sources
PubMed1976

Effect of lithium on dopamine uptake by brain synaptosomes.

Lithium chloride exerts two opposite effects on dopamine uptake by synaptosomes isolated from rat caudate nucleus. Added in vitro, it inhibits dopamine uptake; whereas administered chronically in vivo, it enhances dopamine uptake in vitro. Thus, in vitro, 1, 2.5, 5 and 10 meqiv.l-1 of lithium chloride decrease [3H]dopamine uptake by 13, 17, 25 and 31%, respectively. Synaptosomes isolated from rats treated with lithium chloride for 20 days, show a 23% increase in [3H]dopamine uptake with respect to synaptosomes isolated from control rats. It is suggested that chronic lithium treatment stimulates a compensatory mechanism which overcomes its direct inhibitory effect on [3H]dopamine uptake.

Adrenergic Uptake Inhibitors↗
PubMedDate not supplied

Evidence for a direct action of amphetamine on dopamine metabolism in the rat substantia nigra in vivo.

The intraperitoneal administration of D-amphetamine (0.2--2.5 mg/kg) decreases dihydroxyphenylacetic acid (DOPAC) content not only in the caudate nucleus but also in the substantia nigra. This effect persists both in the substantia nigra and in the caudate nucleus after loss of dopamine-sensitive adenylate cyclase and presumably of dopamine receptors, induced by intrastriatal injection of kainic acid. These results indicate that the effect of amphetamine on DOPAC levels in the nigra is not mediated through a strionigral feedback loop.

3,4-Dihydroxyphenylacetic Acid↗
PubMedDate not supplied

Serotonin is reduced in the frontal cortex of Sardinian ethanol-preferring rats.

Ethanol-naive Sardinian alcohol-preferring (sP) and Sardinian alcohol-non-preferring (sNP) rats were tested to evaluate the levels of serotonin (5-HT) and 5-hydroxyindol-3-yl-acetic acid (5-HIAA) in the frontal cortex, hypothalamus, and nucleus accumbens, and the levels of dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) in the hypothalamus and nucleus accumbens. Compared with the sNP line, the sP rats had lower 5-HT and 5-HIAA concentrations in the frontal cortex, whereas no differences were found in the other brain areas tested, neither for neurotransmitters nor their metabolites. As the decreased 5-HT function is a feature shared by different alcohol-preferring strains, it could be linked to the genetic predisposition to voluntary ethanol consumption.

3,4-Dihydroxyphenylacetic Acid↗
PubMedDate not supplied

Platelet-activating factor production occurs through stimulation of cholinergic and dopaminergic receptors in the chick retina.

In previous work we showed that platelet-activating factor (PAF) was produced upon stimulation of the chick retina with acetylcholine (ACh) and dopamine (DA), via a dithiothreitol-insensitive cholinephosphotransferase (DTT-CPT). Other neurotransmitters were ineffective. Since ACh and DA stimulated PAF production at different stages of development, we advanced the hypothesis that selected cholinergic and dopaminergic receptors were involved. In this paper we demonstrate that only muscarinic or D2 (and not D1 and nicotinic) receptor stimulation induced PAF production in the chick retina either before or after hatching. Moreover, our data show that PAF production was completely prevented by blockage of these receptors by specific antagonists. These data further substantiate the hypothesis that PAF synthesis could be physiologically associated with synapse stimulation.

Acetylcholine↗