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Biomedical subjects

C Bianchi

Publications and source records attributed to C Bianchi.

At least 361 records · Page 20Linked to original sources
PubMed1979

Dopamine modulation of acetylcholine release from the guinea-pig brain.

The effect of dopamine (DA) and apomorphine (Apo) on acetylcholine (ACh) release from guinea-pig brain was investigated (i) in superfused slices of cerebral cortex, caudate nucleus, tuberculum olfactorium, brain stem and (ii) in unrestrained, unanaesthetized animals, provided with epidural parietal cups. DA reduced the ACh release only from slices of caudate nucleus, whereas Apo was also effective in the cerebral cortex. DA and Apo inhibition in caudate nucleus was antagonized by spiroperidol. The injection of DA (1.5 and 5 micromoles) into the cerebral ventricles (i.c.v.) caused a late, moderate behavioural stimulation and enhanced ACh outflow from the parietal cortex. The injection of Apo, either i.c.v. or i.p., promptly elicited similar effects. Spiroperidol 0.5--2 mg/kg i.p. counteracted the behavioural stimulation by Apo and amphetamine, but unexpectedly enhanced the cortical ACh outflow, leaving unaffected the cholinergic responses to Apo and Amphetamine. These results show that DA directly hinders ACh release from the striatal cholinergic structures surviving in vitro, via classical neuroleptic-sensitive receptors. On the other hand, the enhanced cortical ACh outflow caused by DA and DA-mimetic drugs in the unanaesthetized animals is suggestive of a disinhibition of the corticopetal cholinergic neurones, via neuroleptic-insensitive mechanisms. Hence, the 'paradoxical' effect of spiroperidol might represent the consequence of the increased activity of nigral DA cells with collaterals possibly involved in the control of the ascending cholinergic pathways.

Acetylcholine↗
PubMed1979

Inhibition of acetylcholine outflow from guinea-pig cerebral cortex following locus coeruleus stimulation.

Experiments were performed in unanaesthetized guinea-pigs in order to obtain direct evidence that the noradrenergic projections from locus coeruleus (L.C.) to cerebral cortex inhibit the acetylcholine (ACh) release. The animals were provided with left and right epidural cups, to collect outflowing ACh and with a stimulating electrode, positioned in the left L.C. The electrical stimulation of L.C. caused a significant reduction of ACh outflow from both parietal areas. This effect was abolished, reduced or prevented by phentolamine, phenoxybenzamine or reserpine plus alpha-mt pretreatment, hence showing to be alpha-mediated.

Acetylcholine↗
PubMed1978

Noradrenaline inhibition of acetylcholine release from guinea-pig brain.

The effect of noradrenaline (NA) on acetylcholine (ACh) release from guinea-pig brain was investigated in superfused cerebral cortex slices and in unrestrained unanaesthetized animals provided with epidural cups. The amine reduced the ACh release from electrically stimulated tissue and its effect was antagonized by phentolamine and phenoxybenzamine, but not by propranolol and spiroperidol. The injection of NA (150 microgram) into the cerebral ventricles caused sedation, E.Co.G. synchronization and reduced ACh outflow from the parietal cortex. This inhibition was counteracted by alpha-blocking agents. A lower dose of NA (50 microgram) did not change the behaviour, but produced a late increase in ACh outflow, prevented by spiroperidol. These results fit well with the hypothesis that NA restrains, via alpha-receptors, the ACh secretion from the nerve endings and indirectly support the view that the amine reduces the firing rate of the corticopetal cholinergic neurones. The late increase in ACh outflow, observed in vivo, may be referred to secondary activation of the dopaminergic neurones, known to enhance the cortical ACh release in this animal species.

Acetylcholine↗
PubMed1978

[Pulmonary bone-marrow embolism. Analysis of 53 cases].

The medical record and the lung sections were reviewed in 53 autoptic cases with pulmonary bone marrow embolism. In 31 cases the emboli could be ascribed to external cardiac massage, in one case to accident; in the other cases a definite aetiologic factor was lacking. The number of the emboli was largely variable from one section to another and sometimes very high (up to 16). The pulmonary bone marrow embolism has probably a clinical significance particularly when the underlying condition is severe.

Adult↗
PubMed1977

Reduced phenotypic effect on partial trisomy 1q in a X/1 translocation.

A girl with psychomotor retardation and minor physical abnormalities, had an unbalanced X/1 translocation resulting in a partial trisomy 1q and partial monosomy for Xp. The four cases of partial trisomy for the distal segment of 1q reported in the literature showed a much more severely affected phenotype. In the present case the translocated X/1 chromosome is preferentially late replicating and there is spreading of late replication to the translocated 1q segment only in a minor proportion of the cells. The possibility of a non univocous correspondence between spreading of genetic inactivation and cytological spreading of late replication is discussed.

Child↗
PubMed1976

Acute effects of tolamolol on renal function in hypertensive patients.

The renal heamodynamic effects of a single i.v. administration of tolamolol were studied in 9 hypertensive subjects. No change of GFR and ERPF was observed after tolamolol, while urine output decreased and urine creatinine concentration increased. A reduction of the heart rate was confirmed. Blood pressure was unchanged.

Adult↗