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Biomedical subjects

V D'Agata

Publications and source records attributed to V D'Agata.

29 records · Page 2Linked to original sources
PubMed1990

Acetylcarnitine reduces the immobility of rats in a despair test (constrained swim).

Male rats forced to swim in a cylinder adopted an immobile posture. Immobility was reduced by acetylcarnitine (5, 10, and 20 mg/kg) and by antidepressant drugs, such as desipramine and iproniazid, injected 24, 5, and, again, 1 h prior to behavioral testing. Acetylcarnitine also potentiated the anti-immobility effect of antidepressant drugs in the despair test. Chronic (10 days) treatment with acetylcarnitine mimicked the effect found after acute administration. It is possible that the action of the acetylcarnitine on the despair test is indicative of an antidepressant activity of this drug that is dependent on a change in the sensitivity of monoamine receptors in the brain.

Acetylcarnitine↗
PubMed1990

Memory deficits of aged male rats can be improved by pyrimidine nucleosides and n-acetyl-glutamine.

The pyrimidine nucleosides uridine (URI) and cytidine (CYT), alone or associated with n-acetyl-glutamine (NAG), were injected acutely or subchronically to aged (26 months old) male rats of the Sprague-Dawley strain. Learning and memory abilities of the animals were studied with tests of avoidance behavior. The acquisition of active avoidance behavior was studied with the shuttle-box test. A step-through type of passive avoidance task was used to examine the retention of passive avoidance responses. The acquisition of the active avoidance behavior and the retention of the passive avoidance response were reduced in aged animals as compared with those of young animals. Neither the acute treatment of old rats with URI and CYT alone nor that associated with NAG exerted any effect on the behavioral tests. In contrast, the subchronic treatment with URI and CYT was followed by a facilitation of acquisition of active avoidance behavior in the shuttle box and of retention of passive avoidance responses in the dark box. A more potent effect on the acquisition of the shuttle-box behavior and on the retention of passive avoidance reaction was found in animals treated subchronically with the pyrimidine nucleosides associated with NAG. These effects may be related to the role of pyrimidines in the synthesis of ribonucleic acid, which is indispensable for learning and memory processes.

Aging↗
PubMed1989

Prolactin as a protective factor in stress-induced biological changes.

The adenohypophyseal hormone prolactin (PRL) is released during stress of physical and psychological nature. In animals, this hormone facilitates adaptive behavior, induces analgesia, and enhances grooming behavior. It also reduces corticosterone secretion and the incidence of gastric ulcers induced by physical stress. It is possible that PRL plays a protective role against stress-induced biological modifications in animals.

Animals↗
PubMed1988

Dihydroergocristine and memory alterations of aged male rats.

The ergot alkaloid derivative dihydroergocristine (DHECS) was injected acutely or subchronically to aged male rats of the Sprague-Dawley strain, 26 months old, at the dose of 0.05 or 0.1 mg/kg. Learning and memory ability of the animals were studied with tests of avoidance behavior. The acquisition of active avoidance behavior was studied with the shuttle-box and pole-jumping tasks. In the latter, the extinction of active avoidance behavior was also studied. A step-through type of passive avoidance task was used to examine the retention of passive avoidance responses. The acquisition of the active avoidance behavior and the retention of the passive avoidance response were reduced in aged animals as compared to those of young animals. Acute treatment of old rats with DHECS was followed by a facilitation of acquisition of active avoidance behavior in the shuttle box and of retention of passive avoidance responses in the dark box. The effect on the acquisition and extinction of pole-jumping behavior after a single injection of DHECS at the beginning of the acquisition session was restricted to the first acquisition trial. A more potent effect on the acquisition of the shuttle-box behavior and on the retention of passive avoidance reaction was found in animals treated subchronically with the ergot derivative (0.05 and 0.1 mg/kg for 10 days). These rats also showed a facilitation of acquisition and an inhibition of extinction of pole jumping behavior.

Aging↗
PubMedDate not supplied

Protective action of phosphatidylserine on stress-induced behavioral and autonomic changes in aged rats.

Phosphatidylserine (PS) was administered in aged rats subjected to various stressor stimuli in order to evaluate its effect on grooming behavior, core temperature and gastric ulcers. Novelty-induced grooming appeared to be increased in aged rats as compared to young controls. The subchronic intraperitoneal treatment with PS (20 mg/kg/day for 20 days) decreased grooming activity in aged rats, whereas it did not affect that of young animals. Restraint stress induced hyperthermia in both aged and young rats. However, 90 min after the beginning of restraint, PS-treated old rats showed a normalization of core temperature. Furthermore, restraint-plus-cold stress induced gastric ulcers in both aged and young rats. The treatment with PS was followed by a decreased incidence of gastric lesions in aged, but not in young rats. The mechanism of PS protective action against stress-induced behavioral and autonomic changes is unknown, but it may involve the brain level as this drug exerts a noteworthy influence on behavior and autonomic functions.

Aging↗
PubMedDate not supplied

Dihydroergocryptine improves behavioral deficits of aged male rats.

Dihydroergocryptine (DHECP), an ergot alkaloid with potent dopaminergic activity, was injected acutely or subchronically to aged (24 months old) male rats of the F344 strain, at the dose of 0.05 or 0.1 mg/kg. The immobility in the "despair" test (constrained swim) was longer in 24-month-old rats than in younger animals. This behavioral change was reduced in rats treated subchronically with DHECP, but no significant change was found in animals with acute treatment. Aged rats showed an increased haloperidol-induced catalepsy and a reduced motor performance and coordination as compared to animals of 2 and 10 months of age. Acute treatment with DHECP was followed by an attenuation of haloperidol-induced catalepsy and an improvement of motor performance and coordination of aged rats. Similar results were obtained after subchronic treatment with DHECP, but the effect on the rotorod behavior was more potent after subchronic treatment than after acute injection of the drug. It is possible that the improvement of behavioral deficits of aged rats after the treatment with DHECP depends on the facilitating effect of this drug on central dopamine transmission that may be impaired in these animals.

Aging↗
PubMedDate not supplied

The effects of acetyl-l-carnitine on experimental models of learning and memory deficits in the old rat.

Experimental models of learning and memory deficits in aged rats can be studied by means of behavioural tests that provide an important tool for evaluating the effect of drugs on these parameters. Active and passive avoidance tests showed a clear impairment of learning and memory capacity of old rats. These tests were also used to study the behavioural effect of acetyl-l-carnitine in aged rats. The subchronic treatment with this drug was followed by a significant improvement of acquisition and retention of avoidance responses, indicating a facilitation of learning and memory capacity of aged rats.

Acetylcarnitine↗
PubMedDate not supplied

Pyroglutamic acid improves learning and memory capacities in old rats.

The effects of the arginine salt of pyroglutamic acid (2-oxo-pyrrolidone carboxylic acid, PCA) on learning and memory capacities of old rats were studied in a subchronic treatment schedule (i.p. injection of 0.1 and 1 g/kg/day for 15 days). The acquisition and extinction of active avoidance behaviour were studied in a pole-jumping test situation. The retention of passive avoidance response was examined in a step-through passive avoidance task. PCA facilitated the rate of acquisition of pole-jumping response, and inhibited the extinction of the response. The dose of 1 g/kg was more potent than 0.1 g/kg in this respect. Also in the passive avoidance task, the treatment with PCA was followed by an improvement of avoidance retention. These results indicate that PCA is a behaviourally active compound in that it improves learning and memory capacities in old rat.

Aging↗