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Biomedical subjects

F Fadda

Publications and source records attributed to F Fadda.

At least 91 records · Page 5Linked 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↗
PubMed1975

Tryptophan-free diet: a new means for rapidly decreasing brain tryptophan content and serotonin synthesis.

Changes in the synthesis rate of brain serotonin are positively correlated with changes in the concentration of brain tryptophan, indicating that the concentration of tryptophan in the whole brain reflects that at sites of serotonin synthesis. In turn, the concentration of brain tryptophan is positively correlated with that of free serum tryptophan (tryptophan is the only amino acid bound to serum proteins) and negatively to that of other amino acids competing with tryptophan for the same transport from blood to brain. Consistently, experiments in rats have shown that treatments which increase free tryptophan in serum (in respect to competing amino acids) also increase brain tryptophan and serotonin turnover. Conversely, the ingestion of diets containing all amino acids except tryptophan cause a dramatic fall in free serum tryptophan and a parallel decline in brain tryptophan and serotonin synthesis. In man the administration of an amino acid mixture lacking trytophan produces a marked depletion in serum tryptophan concentration.

Amino Acids↗
PubMed1973

[Study on the absorption and utilization of D-galactose and D-glucose by liver and muscular tissue in the albino rat].

In order to compare the disposition of D-galactose and D-glucose in various organs of the rat, we have measured the amount of 14C-galactose and 14C-glucose present in the enteric canal, blood, muscle and liver, 2h. after the oral administration of the labelled esoses. Our results show that the two esoses are ebsorbed almost completely and to the same extent by two hours after their administration, Galactose has a longer half-life than glucose, being more slowly utilized in the synthesis of glycogen in liver and muscle.

Animals↗
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

Suppression of ethanol intake in ethanol-preferring rats by 1,4-butanediol.

The oral administration of 1,4-butanediol (1,4-BD) at doses ranging from 100 to 300 mg/kg, twice daily, produced a dose-dependent reduction (40 to 85%) in the voluntary ethanol intake in rats selectively bred for high preference for ethanol. Treatment with 1,4-BD did not reduce total fluid intake. Repeated 1,4-BD administration (300 mg/kg twice daily for 7 days) suppressed ethanol intake almost completely. After suspension of 1,4-BD treatment, the inhibitory effect on ethanol intake remained significantly low for 2 days. 1,4-BD failed to inhibit aldehyde dehydrogenase to a concentration of 10 mM in rat liver homogenate.

Alcohol Drinking↗
PubMedDate not supplied

Chronic ethanol consumption induces hypomotility in the portal vein of Sardinian alcohol-preferring rats.

In order to study the physiopathological effects of chronic ethanol intake on the smooth muscle of the vascular system, we have assessed the length-tension relationship in isolated portal veins of Sardinian alcohol-preferring (sP) rats. Significant differences in motor performance were found between sP naive and sP rats exposed to ethanol consumption (12% w/v) for 48 weeks. Isolated portal veins of sP rats which consumed ethanol chronically showed a marked decrease of spontaneous and KCl-induced contraction waves when compared to sP naive rats. At optimum length (140% Lr) for maximal contractile performance, the mean amplitude wave in the portal veins of sP drinker rats was about five times less than in sP naive veins. Furthermore, in the veins of sP drinkers, the active curve showed lower values of tension at each elongation of the vascular segment, the maximum value of active tension (7.32 +/- 0.54 mN) represented a reduction in amplitude of about 32% with respect to sP naive veins. These results indicate that long-term ethanol consumption impairs portal vein motility.

Alcohol Drinking↗