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Biomedical subjects

D Rotiroti

Publications and source records attributed to D Rotiroti.

At least 55 records · Page 3Linked to original sources
PubMed1982

Effects of apomorphine on glutamate decarboxylase activity in chick paleostriatum augmentatum.

In young chicks the effects of two different doses of apomorphine, a small dose, producing behavioural and electrocortical sleep and a larger one producing arousal, on GABA content, GAD and GABA-T activities in the paleostriatum augmentatum were studied. The small dose of apomorphine did not affect GABAergic mechanisms in this area, whereas the dose producing behavioural and electrocortical arousal significantly increased GAD activity and GABA content. The results of the present experiments are in favour of an interaction between dopaminergic and GABAergic mechanisms in the avian paleostriatum augmentatum.

Animals↗
PubMed1982

Synergic convulsant effects of dihydrofolic and kainic acid after intracaudate infusion in rats.

In rats the microinjection of kainic acid into the caudate nucleus produced dose-dependent motor and ECoG discharges. Similarly dihydrofolic acid microinfused into the same area produced an intense pattern of stereotyped movements, circling and high voltage electrocortical spikes, sharp waves and other abnormalities similar is those occurring in human epilepsy. The administration of dihydrofolic acid into the same site 10 min after kainic acid significantly increased the percentage of rats showing epileptic motor and ECoG seizures and potentiated the severity and duration of these effects. In conclusion, the present experiments provide evidence for the potentiation of the neurotoxic effects of folic and kainic acid when given in association into the brain.

Animals↗
PubMed1981

Comparative effects of indoprofen and indomethacin on rat hypothalamic prostaglandin-synthetase activity.

The inhibiting effects of indoprofen were compared with those of indomethacin on prostaglandin-synthetase activity in rat hypothalamus. A dose-dependent inhibition of PG-synthetase activity was obtained after intramuscular administration of both antiphlogistic agents; however, indoprofen was found more powerful. In conclusion, the present experiments provide additional evidence against the idea that pyrogen fever is due to the release of PG's of the E type within the hypothalamus since when comparing results obtained with the two antiphlogistic drugs used, no correlation exists between potency in inhibiting PG's synthesis and antipyretic activity.

Animals↗
PubMed1981

Behavioural and body temperature effects of meningococcal lipopolysaccharide after intraventricular injection in adult fowls Gallus domesticus.

The effects of the meningococcal lipopolysaccharide (LPS), given into the II cerebral ventricle of adult fowls, were studied on behaviour and body temperature. Immediately after the administration a marked and dose- dependent behavioural sedation or sleep lasting over 2 hours or more according to the dose was observed. The body temperature effects of LPS were biphasic, i.e. and immediate initial phase of hypothermia lasting about 100 min, followed by a longer-lasting fever response. A pretreatment with phentolamine, an antagonist at alpha-adrenoceptors prevented the hypothermic phase following the endotoxin administration. In conclusion, present experiments show that in comparison to 0-somatic antigen of Shigella dysenteriae, meningococcal endotoxin possesses more marked behavioural effects and a different profile in body temperature effects.

Animals↗
PubMed1981

GABA depletion in chick brain-stem after intraventricular injection of cefazolin.

The effects of cefazolin, given into the III cerebral ventricle at different doses were studied on GABA content, GAD and GABA-T in the brain-stem of young chickens (Gallus domesticus). A dose-dependent fall in GABA content was observed; GABA decrease was evident 15 min after the administration, reached its nadir at 60 min and disappeared at 120 minutes. Glutamate decarboxylase and GABA-transaminase activity were not significantly changed. Present experiments suggest the excitatory and convulsant effects of cefazolin in chicks are related to GABA depletion in the brain-stem.

4-Aminobutyrate Transaminase↗
PubMed1980

Enhanced behavioural, electrocortical and hyperthermic effects of serotonin-like agents after impairment of serotonin transmission in fowl brain.

In adult fowls and in young chicks (Gallus domesticus) the effects were studied on body temperature, behaviour and electrocortical activity of 5-HT and other direct or indirect serotonin agonists given into the III cerebral ventricle in conditions of prolonged impairment of serotoninergic transmission. In chicks pretreated with 5,6-dihydroxytryptamine the subsequent intraventricular injection of 5-HT produced more intense and longer-lasting hyperthermic response and behavioural and electrocortical sleep. On the other hand fenfluramine given intraventricularly in fowls pretreated with 5,6-DHT did not produce significant body temperature and behavioural changes. After 14 and 21 day treatment with methysergide the subsequent administration of 5-HT, fenfluramine and quipazine produced in fowls an hyperthermic response and behavioural sleep more marked and longer-lasting than in control animals. The present experiments show that in conditions of chronic impairment of 5-HT function there is an enhanced behavioural and body temperature response to 5-HT and drugs acting by releasing endogenous 5-HT or 5-HT agonists.

5,6-Dihydroxytryptamine↗
PubMed1980

Cefazolin: a valid model of experimental epilepsy?

In various animal species (chicks, rats and rabbits) the intravenous injection of high doses of cefazolin, a cephalosporin not hitherto reported to produce epileptic seizures, was found to produce epileptiform electrocortrical changes similar to those evoked by intravenous benzylpenicillin. Similar phenomena as those reported after systemic injection were also observed after microinjection of cefazolin into the III cerebral ventricle. In fact, both in chicks and rats cefazolin given by the latter route produced wild running crisis, myoclonic jerks of the limbs and in some instances generalized clonic convulsions. Concomitantly, bilateral electrocortical high voltage bursts of spikes were observed, followed during the intercritic period by periodic bilateral or unilateral single spikes.

Animals↗
PubMed1980

Central effects of histamine and H1 and H2 receptors agonists and antagonists after intraventricular infusion in fowls.

In adult fowls (Gallus deomesticus) the effects of histamine H2 and H2 histamine receptors angonists and antagonists infused into the III cerebral ventricle were studied on behaviour, electrocortical activity and body temperature. Histamine produced biphasic effects, i.e. an initial period of electrocortical synchronization was followed by a longer-lasting behavioural stimulation, electrocortical desynchronization and shivering. Body temperature was increased in a dose-dependent manner. Dimaprit, an agonist at H2 receptors, produced behavioural and electrocortical sleep and decreased body temperature whereas, 2-(2-thiazolyl-)-ethyl-amine, an agonist at H1 receptors, behavioural stimulation, electrocortical desynchronization, vocalization and hyperthermia. Cimetidine, an antagonist at H2 receptors, produced intense behavioural stimulation and electrocortical desynchronization accompanied by vocalization, tachypnoea, occasional escape responses and stereotypies. Body temperature was increased. Mepyramine, an antagonist at H1 receptors, produced behavioural and electrocortical sleep and prevented behavioural excitation elicited by subsequent infusion of histamine and hyperthermia evoked by 2-(2-thiazolyl -ethylamine. Haloperidol, a neuroleptic drug, sharing with mepyramine membrane stabilizing properties, was unable to antagonize histamine-induced behavioural excitation. In conclusion, present experiments provide pharmacological evidence for the existence of H1 and H2 histamine receptors in avian brain and suggest an involvement of histamine H1 and H2 receptors in the control of arousal-sleep and thermoregulatory mechanisms.

Animals↗
PubMed1980

Behavioral and electrocortical effects after intrastriatal cefazolin in rats are antagonized by drugs enhancing GABA-ergic transmission.

Cefazolin, a semisynthetic cephalosporin, reported to reproduce in several animal species an experimental model of epilepsy, was microinjected into the head of the caudate nucleus in rats. The effects on behavior, electrocortical activity and the antagonism by GABA receptor agonists and GABA-transaminase activity inhibitors were studied. Cefazolin given into the III cerbral ventricle produced an intense pattern of behavioral and locomotor stimulation culminating into several episodes of wild-running crisis, myoclonic jerks of the limbs and in some occasions generalized clonic seizures, these effects lasting over 2 h. At the same time bursts of electrocortical high-voltage spikes followed bu intermittent high-voltage single spikes were recorded. Similarly cefazolin, given into the caudate nucleus produced contralateral circling, an increase locomotor activity, myoclonic jerks of contralateral limbs, intense stereotyped behavior and occasionally generalized clonic convulsions. In addition postural changes consisting in tonic contralateral head-neck deviation were observed. This picture was accompanied by epileptic electrocortical changes, i.e. high-voltage spikes, spike-waves complexes, recruiting polyspikes. The subsequent intraventricular or intrastriatal infusion of GABA, GABOB, muscimol or of GABA-transaminase inhibitors, ethanolamine-o-sulphate and GABA-vinyl-GABA was able to antagonize clinical and electrocortical changes evoked by cefazolin. In conclusion, the present results suggest that cefazolin motor and electrocortical effects are due to an impairment of GABA-ergic transmission.

Animals↗
PubMed1980

Antagonism by classical antiepileptics and sodium valproate of cefazolin in induced experimental epilepsy in rats.

The effects of cefazolin, a semisynthetic cephalosporin, on rat behavior, electrocortical activity and on electrocortical spectrum power were evaluated. In addition, the possible antagonism by some antiepileptic agents was studied. Cegazolin, given intravenously in rats, produced generalized convulsions, electrocortical high-voltage spikes and other electrocortical abnormalities similar to those described to occur in human epilepsy. Power spectrum analysis of the electrocortical activity revealed a significant increase in total voltage output during electrocortical epileptogenic discharges. In addition high-voltage spikes induced by cefazolin were easily counted and lasted approximately 90 min. Classical antiepileptic drugs (diphenylhydantoin, phenobarbital and clonazepam as well as sodium valproate were able to counteract electroclinical disorders induced by cefazolin.

Animals↗
PubMed1980

Effects of intraventricular beta-endorphin and D-ALA2-methionine-enkephalinamide on behaviour, spectrum power of electrocortical activity and body temperature in chicks.

In chicks (Gallus domesticus) the effects of beta-endorphin and D-Ala-2-methionine-enkephalinamide given into the third cerebral ventricle on behaviour, electrocortical activity and body temperature were studied. Dose-dependent behavioural stuporous state, decrease in painful stimuli and hypothermic effects were observed after both peptides. Electrocortical high-amplitude slow frequency waves occurred during behavioural sedation and stupor. Spectrum power analysis has allowed to quantify the ECoG activity and has revealed an increase in total voltage output with a predominant increase within the lower spectrum frequencies. The hypothermic effects were significantly more marked when chicks were kept at ambient temperature below their thermoneutral range. Behavioural, electrocortical and body temperature effects were rapidly reversed by naloxone showing that these effects are mediated through an activation of specific opioid receptors.

Animals↗
PubMed1979

Crop-sac response after systemic and intraventricular administration of neuroleptic drugs.

Present experiments were aimed at studying in pigeons the effects of some neuroleptic agents given systemically or into the 3rd cerebral ventricle on PRL secretion and following morphological changes of the crop-sac mucosa both by classical histological methods and scanning electron microscopy. In addition, such changes were also evaluated on the basis of a semiquantitative method using a 1-4 rating scale. 3- or 5-day systemic treatment with reserpine, haloperidol and (ł/-)-sulpiride produced an intense crop-sac response consisting of a marked epithelial hyperplasia and presence of milk-like material. Similarly, a much lower dose of haloperidol, clozapine, and the two enantiomers of sulpiride given into the 3rd cerebral ventricle for 3 consecutive days produced a marked crop-sac response. The l-sulpiride was more active in comparison to the d-enantiomer. In conclusion, present experiments show that, similarly to mammals, in pigeons neuroleptic drugs are able to stimulate prolactin secretion and suggest that these effects are mediated through an action at the hypothalamic and/or pituitary level by removing a tonic dopaminergic inhibition.

Animals↗