PubMed Health⌕ Search

Biomedical subjects

A Tagliamonte

Publications and source records attributed to A Tagliamonte.

At least 55 records · Page 3Linked to original sources
PubMed1985

Opioid activity of lefetamine.

In mice lefetamine, at the dose of 50 mg/kg produces motor hyperactivity and at the dose of 60 mg/kg produces analgesia. Both effects are abolished by naloxone. Displacement studies by using [3H]-Naloxone (Nx), [3H]-D-Ala-Met-Enkephalinamide (DAMA) and [3H]-Ethylketocyclazocine (EKC) showed that lefetamine competes with all these opiates with an affinity 50 times lower than that of morphine. The displacing capacity of lefetamine is decreased in the presence of 50 mM Na+. It is concluded that lefetamine is an opioid agonist.

Anesthetics, Local↗
PubMed1983

In utero exposure to methadone produces a stable decrease of the cortex 5-HT transport system in rats.

Female rats were made dependent to high doses of morphine (400 mg/kg per day) or methadone (60-80 mg/kg per day) and subsequently exposed to adult males. None of the morphine-dependent rats became pregnant while there were no differences in the gestation time and number of young in the litter born to each rat in the methadone and the control groups. The values for muscarinic, serotonergic and opiate receptors measured in the whole brain of the offspring at 1 and 7 days after birth were similar in the control and in the methadone-exposed animals. Brain beta-receptors were lower in rats exposed in utero to methadone at 1 and 7 days. [3H]IMI binding sites were steadily and significantly lower in the whole brain of rats born to methadone-dependent animals than in the brain of controls. In 2 month old animals, the decrease of [3H]IMI binding capacity was associated with a decrease of [3H]5HT uptake. In the light of these findings the authors propose a unifying hypothesis to explain the altered reactivity to morphine of animals treated with opiates during gestation.

Animals↗
PubMed1981

GABA receptors distribution in rat substantia nigra.

The perikarya of the dopaminergic and non-dopaminergic neurons contained in the substantia nigra were selectively destroyed by a proper, local injection of 6-hydroxydopamine or kainic acid, respectively. Both lesions resulted in a marked decrease of the nigral GABA-binding sites. The effect of 6-hydroxydopamine was restricted to the high affinity receptors, while kainic acid specifically decreased the low affinity ones.

Animals↗
PubMed1979

[The behavior of the a and the t indices and the systolic times in myocardial infarct].

A study of the behaviour of the a and telediastolic indices and systolic times in patients presenting the sequelae of myocardial infarction is reported. It is pointed out that the earliness of a and t index variations with respect to those of systolic times is an indication of the sensitivity of the investigation which offers invaluable pointers to subsequent treatment. It is also stressed that previous hypertension and/or coronaropathy are more important than the infarction itself in creating dyskinetic zones of the myocardium and, consequently, the haemodynamic changes observed with phonomechanocardiography.

Coronary Disease↗
PubMed1979

Evidence that a nigral gabaergic--cholinergic balance controls posture.

The intranigral injection of kainic acid (k.a.) (3.5 nM/s.n.) produced a lesion which resulted in a decreased muscarinic receptor binding capacity and in a decreased choline acetyl transferase (CAT) activity confined to the pars reticulata. The unilateral, intranigral injection of carbachol in the substantia nigra (s.n.) produced turning, ipsilateral to the injected side, of dose-related intensity, which was antagonized by scopolamine given either i.p. or intranigrally together with carbachol. The bilateral, intranigral injection of carbachol produced rigid catalepsy, highly resistant to apomorphine administration and antagonized by scopolamine. On the other hand, the catalepsy produced by intranigral picrotoxin was much more sensitive to apomorphine and was disrupted by systemic scopolamine administration. Intranigral scopolamine per se produced either contralateral turning or stereotyped movements consistently, when injected unilaterally or bilaterally, respectively. In addition, scopolamine injected bilaterally in the s.n. but not in the caudate nucleus (c.n.), at the concentration of 64 nM side, was able to antagonize the haloperidol-induced catalepsy and to prevent the tremors and the muscular rigidity produced by arecoline. This effect of scopolamine was surmountable with a higher dose of arecoline. Finally, intranigral muscimol (0.44 nM/s.n.) prevented the occurrence of the parkinsonian syndrome produced by systemic arecoline. It is concluded that the muscarinic receptors present in the s.n. pars reticulata play a role in the control of posture opposite to that of the nigral GABA receptors.

Animals↗
PubMed1978

Intranigral kainic acid: evidence for nigral non-dopaminergic neurons controlling posture and behavior in a manner opposite to the dopaminergic ones.

The unilateral, intranigral administration of kainic acid (k.a.) produced a syndrome characterized by early sequelae of contra- and ipsilateral circling and by a chronic contralateral turning associated with moderate loss of neurons in the pars reticulata. The acute contralateral circling seems to be related to dopaminergic nigro-neostriatal neuron stimulation, since it was prevented by previous intranigral injections of 6-OHDA. The acute ipsilateral circling and the chronic contralateral turning, on the other hand, seem to be independent of the integrity of the dopaminergic system and may be due to an initial stimulation, followed by destruction, of a nigral neuronal system which mediates turning behavior in a manner opposite to that of nigro-striatal dopamine. Treatment with D-amphetamine or apomorphine changed the contralateral into ipsilateral turning, while haloperidol potentiated the contralateral turning. Bilateral injection of k.a. into the nigra resulted in chronic stereotyped sniffing and gnawing, which were not inhibited by haloperidol. Moreover, haloperidol did not produce catalepsy in these animals. It is suggested that the intranigral k.a. injection destroyed a neuronal system antagonistic to dopamine and resulted in a reduction of the response to DA-receptor stimulation of the c. striatum.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1978

Failure of morphine to increase striatal 3,4-dihydroxyphenylacetic acid in fasted rats.

Morphine given to rats fed ad libitum increased the striatal levels of DA and DOPAC while naloxone had no effect. Conversely, after prolonged fasting, morphine failed to increase both DA and DOPAC, while naloxone markedly decreased striatal DOPAC concentration. Intermediate sensitivity to the DOPAC increasing effect of morphine and to the DOPAC decreasing effect of naloxone was present in rats trained to eat their daily meal within 2 h, at different times after feeding. It is concluded that striatal DA synthesis in fasted rats is sustained by an increased endorphin-like activity.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1977

[Phonomechanocardiographic evaluation of hypertensive cardiopathy].

The result of a study of 100 cases of arterial hypertension with various aetiology is presented from a phonomechanocardiographic viewpoint. Findings suggest that irregularities in the apicocardiographic curve recorded in Pachon position, and particularly the "a" wave and the "a" index, are highly sensitive and provide an early warning of contractile deficiency of the left ventricle. The mechanism leading to the pathological appearance of the "a" wave is discussed.

Adult↗
PubMed1976

Possible role of insulin in the transport of tyrosine and tryptophan from blood to brain.

The administration of insulin or the ingestion of glucose increases the concentration of tryptophan and tyrosine in the brain. This increase is associated with a parallel decrease in the concentration of free tryptophan and tyrosine in serum. The results suggest that insulin enhances the transport of tyrosine and tryptophan from blood to brain. The results, moreover, suggest that exogenous or endogenous insulin enhances the transport of tyrosine and tryptophan from blood to brain.

Animals↗