Laura Betti

Platelet serotonin transporter in patients with diarrhea-predominant irritable bowel syndrome both before and after treatment with alosetron

Platelet serotonin transporter in patients with diarrhea-predominant irritable bowel syndrome both before and after treatment with alosetron

Alteration of serotonin transporter density and activity in fibromyalgia

The aim of the study was to evaluate the kinetic parameters of a specific serotonin transporter (SERT) and serotonin uptake in a mentally healthy subset of patients with fibromyalgia. Platelets were obtained from 40 patients and 38 healthy controls. SERT expression and functionality were evaluated through the measurement of [3H]paroxetine binding and the [3H]serotonin uptake itself. The values of maximal membrane binding capacity (Bmax) were statistically lower in the patients than in the healthy volunteers, whereas the dissociation constant (Kd) did not show any statistically significant variations. Moreover, a decrease in the maximal uptake rate of SERT (Vmax) was demonstrated in the platelets of patients, whereas the Michaelis constant (Km) did not show any statistically significant variations. Symptom severity score (tiredness, tender points index and Fibromyalgia Impact Questionnaire) were negatively correlated with Bmax and with Vmax, and positively correlated with Km. A change in SERT seems to occur in fibromyalgic patients, and it seems to be related to the severity of fibromyalgic symptoms.

New 1,2,3-triazolo[1,5-a]quinoxalines: synthesis and binding to benzodiazepine and adenosine receptors. II.

On pursuing research about 1,2,3-triazolo[1,5-a]quinoxalines, in this paper we report synthesis and binding assays toward the benzodiazepine and A(1) and A(2A) adenosine receptors, of a new series of derivatives, bearing some structural changes (introduction of fluorine and trifluoromethyl in the seventh position, amino substituents in the fourth position, benzyl group in the fifth position and aroyl substituents in the third position). The biological tests have shown that only the 7-fluorosubstituted compounds 3a and 4a and the N-benzyl derivative 7 have a good affinity toward the benzodiazepine receptors, while only the 7-trifluoromethyl substituted compound 3b presents a moderate affinity with low selectivity toward the A(1) adenosine receptors. The other structural modifications strongly decreased biological activity.

The trace element content of top-soil and wild edible mushroom samples collected in Tuscany, Italy

The amount of the trace elements As, Ba, Cd, Cr, Cu, Hg, Li, Mn, Ni, Pb, Rb, Se, Sr, and Zn was measured in top soils and edible mushrooms, Boletus edulis, Macrolepiota procera, collected at five distinct green microhabitats inside the Lucca province, North-Central Italy (years 2008–2009). Results showed a top soil element content within the Italian statutory limits. Concerning the amount of mushroom elements, we observed significant species-differences obtaining higher levels of Ni, Rb, and Se in B. edulis or As, Pb, Cu in M. procera. Bioaccumulation factors (BCFs: element in mushroom/element in soil) resulted species-dependent and element-selective: in particular, B. edulis preferentially accumulated Se (BCFs varying from 14 to 153), while M. procera mainly concentrated Cu (BCFs varying from 5 to 15). As well, both species displayed between-site BCF differences. By a multivariate principal component approach, cluster analysis (CA), we could resolve two main clusters of soil element composition, corresponding to the most ecologically divergent sites. Besides, CA showed no cluster relating to element contents of B. edulis at the different collection sites, while a separation in groups was found for M. procera composition with respect to harvesting locations, suggesting uptake systems, in this saprotrophic species, sensitive to microhabitat. Regarding consumer safety, Cd, Hg, Pb levels resulted sometime relevant in present samples, never reaching values from current literature on mushrooms collected in urban-polluted areas. Our findings encourage a deeper assessment of the molecular mechanisms of metal intake by edible mushrooms, encompassing genetic biochemical and geo-ecological variables, with particular awareness to element bioavailability in soils and fungi.

ATP, calcium and magnesium levels in platelets of patients with primary fibromyalgia

OBJECTIVES To evaluate the intracellular levels of the high energy adenosine triphosphate nucleotide ATP and essential divalent cations, calcium and magnesium, in platelets of patients affected by primary fibromyalgia syndrome (FMs). DESIGN AND METHOD Platelet ATP and cation concentrations were measured in 25 patients affected by FMs and 25 healthy volunteers through a chemiluminescent and a fluorimetric assay, respectively. RESULTS Significant lower ATP levels were observed inside platelets of FM patients (fmol ATP/plt: 0.0169+/-0.0012 vs. healthy controls, fmol ATP/plt: 0.0306+/-0.0023, mean+/-SEM) (*** P<0.0001). A trend towards higher calcium concentrations (P=0.06) together with significant increased magnesium levels were also reported in platelets of patients by comparison with controls (P=0.02). CONCLUSIONS This preliminary study suggests that disturbances in the homeostasis of platelet ATP metabolism-signaling and calcium-magnesium flows might have a relevance in the pathogenesis of FMs.

Synthesis and biological activity of new 1,4-benzodioxan-arylpiperazine derivatives. Further validation of a pharmacophore model for α1-Adrenoceptor antagonists

A series of WB4101 (1)-related benzodioxanes (2-17) have been synthesized by replacing the phenoxyethyl moiety of 1 with a N-alkyl piperazine bearing a cyclic substituent (a substituted or unsubstituted phenyl group, a pyridine or pyridazinone ring, a furoyl moiety) at the second nitrogen atom. The binding profile of these compounds has been assessed by radioligand receptor binding assay at alpha(1)- and alpha(2)-adrenoceptors, in comparison to prazosin and rauwolscine, respectively. Moreover, structure-activity relationships have been derived for compounds 2-17 based on their fitting to a pharmacophore model for alpha(1)-adrenoceptor antagonists recently proposed by our research group. In a parallel way, the same compounds have been used to further test the predictive power and statistical significance of the model itself. The accuracy of the results obtained also in this case revealed the robustness of the calculated pharmacophore model and led to the identification of the molecular structural moieties which are thought to contribute to the biological activity.

α1-Adrenoceptor antagonists. 5. Pyridazinone-arylpiperazines. Probing the influence on affinity and selectivity of both ortho-Alkoxy groups at the arylpiperazine moiety and cyclic substituents at the pyridazinone nucleus

Our previous work on pyridazinone-arylpiperazine derivatives suggested some structural features that a compound should have to show high affinity and good selectivity for alpha(1) adrenoceptors (AR) with respect to alpha(2)-AR. Accordingly, two classes of new alkoxyphenylpiperazinylheptylpyridazinones were designed and synthesized to evaluate the effect of the alkoxy substituent on affinity and selectivity. As expected, affinity increased with larger alkoxy groups. Affinity values are all comparable with that of the reference compound (prazosin), with the exception of compound 1c found 4.5-fold more active than prazosin.

New insight into the central benzodiazepine receptor-ligand interactions: design, synthesis, biological evaluation, and molecular modeling of 3-substituted 6-phenyl-4H-imidazo[1,5-a][1,4]benzodiazepines and related compounds.

3-Substituted 6-phenyl-4H-imidazo[1,5-a][1,4]benzodiazepines and related compounds were synthesized as central benzodiazepine receptor (CBR) ligands. Most of the compounds showed high affinity for bovine and human CBR, their K(i) values spanning from the low nanomolar to the submicromolar range. In particular, imidazoester 5f was able to promote a massive flow of (36)Cl(-) in rat cerebrocortical synaptoneurosomes overlapping its efficacy profile with that of a typical full agonist. Compound 5f was then examined in mice for its pharmacological effects where it proved to be a safe anxiolytic agent devoid of the unpleasant myorelaxant and amnesic effects of the classical 1,4-benzodiazepines. Moreover, the selectivity of some selected compounds has been assessed in recombinant α(1)β(2)γ(2)L, α(2)β(1)γ(2)L, and α(5)β(2)γ(2)L human GABA(A) receptors. Finally, some compounds were submitted to molecular docking calculations along with molecular dynamics simulations in the Cromers GABA(A) homology model.

Distribution of [3H]GR65630 binding in human brain postmortem.

We investigated the distribution of serotonin (5-HT) receptors of type 3 (5-HT3) in human brain areas, by means of the the specific binding of [3H]GR65630. The brains were obtained during autoptic sessions from 6 subjects. Human brain membranes and the binding of [3H]GR65630 were carried out according to standardized methods. The highest density (Bmax ± 6 SD, fmol/mg protein) of [3H]GR65630 binding sites was found in area postrema (13.1 ± 9.7), followed at a statistically lower level, by nucleus tractus solitarius (6.7 ± 3.4), nervus vagus (5.5 ± 2.1), striatum (4.8 ± 2.4) with a progressive decrease in amygdala, olivar nuclei, hippocampus, olfactory bulbus and prefrontal cortex, and then by the other cortical areas and the cerebellum, where no binding was detected. These observations extend previous findings on the distribution of 5-HT3 receptors and confirm interspecies variations that might explain the heterogeneous properties of 5-HT3 receptors in different animals.

Tryptophan Biochemistry: Structural, Nutritional, Metabolic, and Medical Aspects in Humans

L-Tryptophan is the unique protein amino acid (AA) bearing an indole ring: its biotransformation in living organisms contributes either to keeping this chemical group in cells and tissues or to breaking it, by generating in both cases a variety of bioactive molecules. Investigations on the biology of Trp highlight the pleiotropic effects of its small derivatives on homeostasis processes. In addition to protein turn-over, in humans the pathways of Trp indole derivatives cover the synthesis of the neurotransmitter/hormone serotonin (5-HT), the pineal gland melatonin (MLT), and the trace amine tryptamine. The breakdown of the Trp indole ring defines instead the “kynurenine shunt” which produces cell-response adapters as L-kynurenine, kynurenic and quinolinic acids, or the coenzyme nicotinamide adenine dinucleotide (NAD+). This review aims therefore at tracing a “map” of the main molecular effectors in human tryptophan (Trp) research, starting from the chemistry of this AA, dealing then with its biosphere distribution and nutritional value for humans, also focusing on some proteins responsible for its tissue-dependent uptake and biotransformation. We will thus underscore the role of Trp biochemistry in the pathogenesis of human complex diseases/syndromes primarily involving the gut, neuroimmunoendocrine/stress responses, and the CNS, supporting the use of -Omics approaches in this field.