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A Cagnotto

Publications and source records attributed to A Cagnotto.

10 recordsLinked to original sources
PubMed1992

Pyrrolobenzodiazepines and related systems. 2. Synthesis and biological properties of isonoraptazepine derivatives.

The synthesis of some derivatives and analogues of 12,13,14,14a-tetrahydro-9H,11H-pyrazino-[2,1-c]pyrrolo[1,2- a][1,4]benzodiazepine (isonoraptazepine) is reported. The new derivatives have been subjected to pharmacological tests for evaluation of antidepressant effects. Neurobehavioral assays were also carried out to acquire data on neurotoxicity and sedative action. Isonoraptazepine analogues and derivatives lacked the pharmacological activity of mianserin and aptazepine and showed properties similar to imipramine. Molecular modeling studies revealed structural similarities between isonoraptazepine derivatives and imipramine, thus explaining the similar pharmacological profile found in some of the tests employed. Based on pharmacological data the title compounds cannot be regarded as alpha 2 presynaptic adrenoceptors antagonists. In vitro studies for receptor binding gave support to this observation. The above studies lead us to conclude that isonoraptazepine derivatives are conformationally restricted analogues of imipramine, but their antidepressant activity cannot be correlated to inhibition of 5HT uptake. Among the derivatives tested, 7b and 8e show some affinity for the d-fenfluramine receptor site, a serotonin presynaptic site connected with anorectic activity.

Animals↗
PubMed1992

Hepatic protoporphyria is associated with a decrease in ligand binding for the mitochondrial benzodiazepine receptors in the liver.

Protoporphyrin IX (PP) and N-methylprotoporphyrin IX (N-MePP) added in vitro to liver membranes reduced dose-dependently the affinity of [3H]PK 11195 for the mitochondrial benzodiazepine receptors (MBRs), the latter being about 20 times more potent (Ki 4.5 and 0.25 microM). Preincubation of these two porphyrins with liver homogenates for 120 min at 4 degrees resulted in significant inhibition of [3H]PK 11195 binding even after repeated washings of the membranes due to the residual presence in the membranes of about 35 and 5% of PP and N-MePP, respectively. Thus, the hypothesis that an in vivo increase in the hepatic porphyrin content modifies the binding of the isoquinoline PK 11195 to the MBRs was investigated in an experimental model of protoporphyria. PP and N-MePP were allowed to accumulate in vivo through treatment with 3,5-diethoxycarbonyl-1, 4-dihydrocollidine (DDC) (100 mg/kg i.p., once), and rats were killed 5 h after treatment when hepatic porphyrin accumulation was marked (10-fold increase), PP predominating. In the liver, treatment reduced the affinity (Kd) of [3H]PK 11195 for MBRs (from 3.56 to 15.37 nM, P < 0.01) and the maximum number of binding sites (Bmax) (55% decrease, P < 0.05); the affinity (Ki) of RO 5-4864 for [3H]PK 11195 binding sites was also reduced (from 23.9 to 72.99 nM, P < 0.05). No significant differences were found in the brain cortex. Liver and brain diazepam binding inhibitor levels and plasma corticosterone levels were unchanged. The reduction in [3H]PK 11195 binding to MBRs in the liver of DDC-treated rats thus appears to be attributable to a specific effect of the DDC-induced formation of the two protoporphyrins; this conclusion suggests that in hepatic protoporphyria processes modulated by MBRs may be altered.

5-Aminolevulinate Synthetase↗
PubMed1992

Synthesis and benzodiazepine receptors affinity of 2,3-dihydro-9-phenyl-1H-pyrrolo[3,4-b]quinolin-1-one and 3-carbethoxy-4-phenylquinoline derivatives.

A series of 2,3-dihydro-9-phenyl-1H-pyrrolo[3,4-b]quinolin-1-one derivatives and related compounds were tested for their ability to bind benzodiazepine receptors (BZRs). Most of the synthesized compounds showed micromolar affinity for BZR peripheral type, but not for the central one, with the exception of compound 4m which displayed an IC50 = 0.407 microM, only 2 fold higher than IC50 for chlordiazepoxide.

Animals↗
PubMed1990

Quantitative autoradiographical analysis of the age-related modulation of central dopamine D1 and D2 receptors.

Quantitative autoradiography of [3H]SCH 23390 and [3H](-)-sulpiride binding was performed in the brain of rats of various ages (3, 11 and 24 months) in order to study the changes in D1 and D2 receptor density with age. Binding of [3H]SCH 23390 in the caudate-putamen decreased progressively and markedly at rostral levels in 11- and 24- compared with 3-month-old rats (max. decrease -63%) while at caudal levels significant decrease was observed only in 24-month-old rats. [3H](-)-Sulpiride binding progressively decreased during aging in the caudate-putamen at rostral levels and the decrease was more pronounced laterally (-70% at 24 months), while at caudal levels no significant decrease was observed. D1 and D2 binding sites also decreased in the nucleus accumbens and olfactory tubercle of aged rats, while in the substantia nigra only the D1 receptors appeared to be modified with aging. No change was found in the entopeduncular nucleus, amygdala, frontoparietal, suprarinal-prefrontal and anterior cingulate cortex. The results indicate that the age-associated decrease of D1 and D2 receptors is not widespread, being confined to dopaminergic areas with high density of dopamine receptors.

Aging↗
PubMed1990

In-vivo radiolabelled oxiracetam binding to rat brain.

The in-vivo binding of [3H]oxiracetam has been studied in brain areas of rats examined 30 min after i.c.v. injection. Soluble radioactivity accounted for more than 90% of total radioactivity in all the structures considered and was not affected by co-injection with a 1000-fold excess of unlabelled oxiracetam. Both total and bound radioactivity showed a marked regional distribution, with highest concentrations in the septum, followed by the hippocampus; the cerebral cortex, striatum and cerebellum had the lower concentrations of radioactivity. Computer-assisted quantitative autoradiography with [14C]oxiracetam confirms these findings. Analysis of [3H]oxiracetam bound to membranes indicated that, after co-injection with a 1000-fold excess of unlabelled oxiracetam, there was a significant reduction of binding only in the septum, hippocampus and cerebral cortex. These results suggest that in those cerebral structures oxiracetam binds to saturable sites.

Animals↗
PubMed1990

5-HT and benzodiazepine receptor ligands. III. Synthesis and receptor affinities of 1,2,4-triazolo[4',3':1,6]pyridazino[4,5-b]quinoline and 2,3-dihydro-9-phenyl-1H-pyrrolo[3,4-b]quinoline-1-one derivatives.

The syntheses as well as 5-HT and Benzodiazepine receptor binding studies of some 1,2,4-Triazolo[4',3':1,6]piridazino[4,5-b]quinoline and 2,3-Dihydro-9-phenyl-1H-pyrrolo[3,4-b]quinoline-1-one derivatives are reported. While the triazole-containing heterocycles are devoid of any biological activity, 2-benzyl-2,3-dihydro-9-phenyl-1H-pyrrolo[3,4-b]quinoline-1-one shows some affinity for the central type of benzodiazepine receptors.

Animals↗
PubMed1990

Pyrrolobenzodiazepine and related systems. I. Synthesis and pharmacological evaluation of new 5,6-dihydro-4H-pyrrolo[1,2-a][1,4]benzodiazepine derivatives.

Some new 5,6-dihydro-4H-pyrrolo[1,2-a][1,4]benzodiazepine derivatives substituted at the 5 position have been synthesized and tested to evaluate their antidepressant and neuropsychopharmacological activities. The antinociceptic action of these compounds has been also assayed. The introduction of an ethoxycarbonyl group at the 4 position generally decreased the antidepressant effect.

Analgesics↗
PubMed1990

Research on compounds with psychotropic activity. IX--Synthesis of 6-p-methoxyphenylpyrrolo[2,1-d][1,5]benzothiazepines and evaluation of their affinities for BDZ and GABA receptor subtypes.

6-p-Methoxyphenylpyrrolo[2,1-d][1,5]benzothiazepin-7(6H)-one (IV), cis-7-acetoxy-6,7-dihydro-6-p-methoxyphenylpyrrolo[2,1-d] [1,5]benzothiazepine (V) and some significant 7-acyloxy-6-p-methoxyphenylpyrrolo[2,1-d][1,5]benzothiazepines (VI a-g) were synthesized and tested in vitro for inhibition of the specific binding of 3H-Flunitrazepam, 3H-PK 11195, 3H-Muscimol and 3H-(-)Baclofen to central and peripheral benzodiazepine, GABA-A and GABA-B receptors, respectively. The compounds (IV), VI a) and (VI c) were active on the peripheral benzodiazepine receptor; in particular (VI a) and (VI c) were very active. The compound (VI g) showed an affinity, even though scanty, for the central benzodiazepine receptor.

Animals↗