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F Fadda

Publications and source records attributed to F Fadda.

98 records · Page 6Linked to original sources
PubMedDate not supplied

Long-term voluntary ethanol consumption induces impairment of the mechanical performance in the papillary muscle of Sardinian alcohol-preferring rats.

The effects of chronic (26 weeks) ethanol consumption on cardiac muscle contractility in Sardinian alcohol-preferring drinkers (sP-D) and Sardinian alcohol-preferring naive (sP-N) rats were investigated. Experiments were carried out 1 week after ethanol administration ceased. Length-tension and force-frequency responses in left ventricular papillary muscles from both sP-D and sP-N rats were recorded in vitro. Papillary muscles were gradually stretched in steps of 5% of the reference (initial) length (L(r)) from 100 to 130% L(r). In sP-D rats, length-tension relationships showed a significant reduction in active tension: at optimal length for maximum active tension (130% L(r)), the developed force value (1.38 +/- 0.36 mN/mg, dry tissue) was 54% lower than that found in sP-N rats (3.16 +/- 0.6 mN/mg, dry tissue). In sP-D papillary muscles, a decrease in contractile behaviour was also observed in force-frequency responses (0.03-120 pulse/min), when compared with sP-N rats; developed force was found to be reduced by about 2.5 times. These results indicate that long-term ethanol consumption impairs the mechanical performance of sP papillary muscle, inducing a negative inotropic effect.

Alcohol Drinking↗
PubMedDate not supplied

Constant absolute ethanol intake by Sardinian alcohol-preferring rats independent of ethanol concentrations.

The present study was designed to evaluate ethanol drinking behaviour in Sardinian alcohol-preferring (sP) and Sardinian alcohol-non-preferring (sNP) rats in the presence of different ethanol concentrations. Ethanol intake was tested under the two-bottle, free-choice regimen and continuous access schedule. Ethanol-naive sP and sNP rats were initially given ethanol solution at the standard, constant concentration of 10% (v/v) for 8 consecutive days (Phase 1). As expected, daily ethanol intake in sP rats rose from 4 to approximately 6 g/kg; in contrast sNP rats consumed < 10 g/kg/day ethanol. Subsequently, an ascending series of ethanol concentrations, ranging from 3 to 60% (v/v), was presented to sP and sNP rats over a 28-day period (Phase 2). At concentrations varying from 7 to 30%, sP rats consumed constant amounts of absolute ethanol per kg of body weight (approximately 6.0 g/kg/day). Daily ethanol intake in sNP rats remained constantly lower than 1.0 g/kg, irrespective of the ethanol concentration. Data from Phase 2 demonstrate the ability of sP rats to precisely adjust daily ethanol intake and support the hypothesis that voluntary ethanol drinking in sP rats is sustained by specific pharmacological effects of ethanol.

Alcohol Drinking↗
PubMedDate not supplied

Tryptophan metabolism in male Sardinian alcohol-preferring (sP) and -non-preferring (sNP) rats.

Parameters of tryptophan (Trp) and related metabolism were compared in male Sardinian alcohol-preferring (sP) and -non-preferring (sNP) rats. Liver Trp pyrrolase activity was 38-58% higher in sP than in sNP rats, and this was associated with a greater expression of the enzyme mRNA as measured by multiprobe oligonucleotide solution hybridization. Moderately (about 10-19%), but significantly, lower concentrations of free serum, total serum, and brain Trp were also observed in sP compared with sNP rats. Concentrations of whole brain 5-hydroxytryptamine (5-HT) and its major metabolite 5-hydroxyindol-3-yl-acetic acid (5-HIAA) were, however, 14-21% higher in sP rats. Serum corticosterone concentration was 18% higher in sP rats. We conclude that alcohol preference in Sardinian rats is associated with increased liver Trp pyrrolase activity and mRNA expression leading to a decrease in Trp availability to the brain. Although a simple serotonin deficiency could not be demonstrated in the whole brain, the possibility could not be ruled out that a deficiency may be present in discrete areas of the brain of the sP rat.

Alcoholism↗
PubMedDate not supplied

[Role of tryptophan in the physiological regulation of brain serotonin synthesis (author's transl)].

Tryptophan hydroilase in brain, normally is not saturated by its substrate; therefore the rate of tryptophan hydroxilation in brain is controlled by the concentration of tryptophan. In the other hand, brain tryptophan content is controlled by the ratio of the concentration of free tryptophan (i.e. not bound to serum proteins) to that of the other circulating amino acids, wich compete for the same transport mechanism from blood to brain. The administration of an amino acid mixture, containing all essential amino acids but not tryptophan, caused a parallel depletion of total and free serum tryptophan and of tryptophan and serotonin in brain. The mechanism of the observed fall in serum tryptophan is a rapid removed of endogenous tryptophan from circulation, secondary to an increased incorporation of tryptophan into proteins by the liver. These results suggest the hypothesis that brain serotonin synthesis is controlled by a perpherical mechanism.

Amino Acids↗
PubMedDate not supplied

[Intestinal glucose absorption in rats of different ages (author's transl)].

We studied the intestinal glucose absorption in a colony of rats at different ages. The experiment was carried out on animals of the following ages: 3, 5, 10 and 20 months. All rats were fasted 48 hr prior to the administration of 2 ml. 50% glucose solution by an oesophageal sound. After one hour the animals were killed, the intestine was washed with a determinated quantity of distilled water and homogenized, to find out any trace of glucose in mucose cells. Glucose absorption was calculated as the difference between the quantity introduced and that left in the intestine. The results of this experiment show that glucose absorption expressed as mg/100 gm. body weight/hr decrease significantly during the first 10 months, with no marked changes there after. Absorption rapidly increase during the first 16 month, if expressed as mg/hr. This is probably due to a remarkable weight increase without a proportional increase of intestinal length.

Age Factors↗
PubMedDate not supplied

Ethanol-stress interaction on dopamine metabolism in the medial prefrontal cortex.

The effect of foot-shock and ethanol (2 g/kg per os) and the combination of the two on dopamine (DA) metabolism in the medial prefrontal cortex (MPFC) was studied in rats. Electric foot-shock stress (20 min stimulation) decreased DA concentration by 30% and increased dihydroxyphenylacetic acid (DOPAC) concentration by 65%. Ethanol (2 g/kg orally) decreased DA concentration by 20%, but, unlike foot-shock, failed to modify DOPAC levels. Neither treatments modified homovanillic acid (HVA) levels. The combination of ethanol (30 min before shock) and foot-shock produced about a 50% depletion of DA content and 30% increase in HVA, but no change in DOPAC levels. It is suggested that both ethanol and foot-shock activate DA release in the MPFC, but ethanol decreases DA retrieval by nerve terminals and, therefore, prevents intraneuronal deamination of the amine.

3,4-Dihydroxyphenylacetic Acid↗
PubMedDate not supplied

[Malnutrition].

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Humans↗