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Biomedical subjects

G Calderini

Publications and source records attributed to G Calderini.

46 records · Page 3Linked to original sources
PubMed1975

Homovanillic acid and 5-hydroxyindole-acetic acid in the csf of patients after a severe head injury. I. Lumbar csf concentration in chronic brain post-traumatic syndromes.

Lumbar CSF concentrations of homovanillic acid (HVA) and 5-hydroxyindole-acetic acid (5HIAA) have been determined in ten patients suffering from chronic brain post-traumatic syndromes, at various length of time after the brain trauma. Lower concentrations of HVA (mean 21 +/- 14 mug/ml) compared to controls (mean 46 +/- 10 mug/ml) was observed in 7 cases; 5HIAA levels were within normal values. The 5HIAA/HVA ratio (1.59 +/- 0.66) was significantly higher (p less than 0.001) than the one recorded in controls (0.66 +/- 0.10). Monitoring of lumbar HVA and 5HIAA over time, before, during and after L-dopa treatment, revealed interesting correlations between modification of clinical picture and the levels of monoamines acid metabolites. The data indicate a profound alteration of brain monoamines in chronic syndromes following a severe head injury and suggest that measurements of lumbar HVA and 5HIAA in these patients may be of euristic and diagnostic value.

Adolescent↗
PubMed1975

Homovanillic acid and 5-hydroxyindole-acetic acid in the csf of patients after a severe head injury. II. Ventricular csf concentrations in acute brain post-traumatic syndromes.

Ventricular concentrations of homovanillic acid (HVA) and 5-hydroxyindole-acetic acid (5HIAA) were measured in 7 patients a few days after a severe traumatic brain injury. Both acid metabolites were elevated in respect to control patients values, however, the rise was more consistent for 5HIAA (258 +/- 86 ng/ml) with a 5HIAA/HVA ratio of 0.85 +/- 0.35. The data support previous hypothesis on the profound involvement of serotoninergic structures in the early stages of acute traumatic brain syndromes and on the role of 5HT in maintaining edema and vasospasm.

Adolescent↗
PubMedDate not supplied

Age-dependent spontaneous EEG bursts in rats: effects of brain phosphatidylserine.

During aging, male Sprague-Dawley rats display increasing frequency of bursts of seizure-like EEG patterns. They also have a decreased retention of passive avoidance response and a loss of spontaneous alternation in a Y maze. A study was made on the effects of chronic administration of phosphatidylserine in aged rats. It was found that BC-PS reduced by 65% the number of seizures, and by 70% their duration. It also facilitated retention of passive avoidance and of spontaneous alteration behavior. These results suggest that phosphatidylserine can affect electrophysiological and behavioral parameters in aged rats probably by counteracting age-related biochemical changes.

Aging↗
PubMedDate not supplied

D-1 dopamine receptors labelled with 3H-SCH 23390: decrease in the striatum of aged rats.

The effects of age on the binding parameters of 3H-SCH 23390, the most selective D-1 dopamine receptor ligand available at present, were studied in membrane preparations from rat striatum. When compared with 3 month old animals, there was a significant decrease in the density of 3H-SCH 23390 binding sites in 20 month old (-37%) and in 26 month old (-44%) rats, without alterations in the apparent dissociation constant values. No significant changes in the density or affinity of D-1 DA receptors were observed in 14 month old rats. In view of the behavioural effects mediated by D-1 DA receptors recently described (i.e., grooming, stereotypies and EEG desynchronization), the decrease in the density of these receptors in senescent rats may underlie some of the age-related alterations in dopaminergic functions in the rat brain.

Aging↗
PubMedDate not supplied

Age-related changes in metabolic responses to chronic monoamine depletion in central dopaminergic and serotonergic systems of rats treated with reserpine.

Groups of 5, 15, and 27-month-old rats were treated with reserpine (5 mg/kg IP) and killed after 1, 7, 14, and 21 days. Reserpine's effects on dopamine (DA) and serotonin (5HT) metabolism were studied in the striata and limbic areas, on the basis of changes in metabolite concentrations and a calculated index [delta(C/M)] expressing changes in the molar ratio between metabolite and parent monoamine. Twenty-four hours after drug treatment, when the two monoamines reached a new steady-state, about 10% of the normal concentration, there was evident enhancement in the metabolism of striatal DA, indicated by HVA levels and delta(C/M) changes. This increase was significantly lower in the senescent rats. In contrast with HVA, the levels of DOPAC were lowered in reserpinized rats. This effect, present in all three age groups, lasted up to 21 days in young and 14 days in adult and old rats. However, for this metabolite too, the delta(C/M) indicated an increase in its formation which was lower in 27-month-old rats. Similar effects were observed in limbic areas, but here the age-related differences were less evident. Serotonin metabolism was also increased by reserpine as indicated by the delta(C/M). This parameter was lower in young than in adult and old rats, at least in limbic area. Similarly, 5HIAA increased only in the senescent rats. These age-related differences were not evident in striata. In this rat population, aging apparently modified the compensatory metabolic responses of some dopaminergic and serotonergic systems. The direction of these changes, however, depends on the system and the brain region considered.

3,4-Dihydroxyphenylacetic Acid↗
PubMedDate not supplied

Differential response to immobilization stress of striatal dopaminergic and hippocampal noradrenergic systems in aged rats.

The effect of restraint stress on synthesis of central norepinephrine (NE) and dopamine (DA) was studied in adult and old rats. The rate of in vivo synthesis of the two catecholamines was determined in hippocampus (a prevalently noradrenergic area) and in striatum (a prevalently dopaminergic area) by measuring the accumulation of DOPA for 60 min after decarboxylase inhibition. NE synthesis was stimulated by stress in the first 30 min, after which the accumulation of DOPA declined. The stimulation was much greater in old rats. In striatum, endogenous DOPA concentration was significantly lower in old rats. Stress significantly enhanced DOPA accumulation in the first 30 min in both age groups but after this interval accumulation continued linearly only in young rats. These results indicate that in aged rats the response to stress of some noradrenergic and dopaminergic systems may be altered in opposite directions.

Aging↗
PubMedDate not supplied

Evaluation of tuberoinfundibular dopamine function by neuropharmacologic means in old male rats.

Baseline prolactin (PRL) levels and the PRL-lowering effect of nomifensine (Nom), an indirect dopamine (DA) agonist, were evaluated in young adult (3-5 months) and old (21 and 27 months) male rats. In addition, PRL responsiveness to acute or repeated administration of haloperidol (Hal), a DA receptor antagonist, was assessed in either young or old rats. Baseline PRL levels did not differ significantly between young and aged rats either when rats were killed by decapitation or underwent sampling from the retro-orbital venous plexus. Administration of Nom (10.0 mg/kg i.p.), a drug which inhibits PRL levels in normal rats and humans but lacks any action in conditions of impaired tuberoinfundibular DA (TIDA) function, affected PRL levels in aged rats not differently than in young rats. The PRL inhibition induced by the drug was greater in both groups when basal PRL levels were higher. Acute administration of Hal (0.5 mg/kg i.p.) increased significantly and to the same extent as PRL levels in aged and young rats. In aged rats treated chronically with Hal (0.5 mg/kg i.p., twice daily for 14 days) and sampled at the 8th day, 1 h after the first daily Hal injection, plasma PRL rose to levels about 3-fold as high as those after the first injection; in young rats, instead, the PRL-releasing effect of Hal was similar to that evoked by the first administration. 3 days after Hal withdrawal, baseline PRL levels were significantly higher in aged Hal-treated rats than in vehicle-injected or young Hal-treated rats and so were pituitary concentrations of PRL.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMedDate not supplied

Determination of HVA and 5-HIAA in ventricular CSF of patients with brain tumors.

Ventricular concentrations of homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) were evaluated in 17 patients suffering from brain tumor and 4 pseudo-tumor patients. Significant differences were observed in those patients in whom the tumor leads to a marked modified CSF dynamic. No relationship were on the contrary observed between VFP and HVA or 5-HIAA levels.

Adult↗