Moderate Depression Promotes Posttraumatic Growth (Ptg): A Young Population Survey 2 Years after the 2009 L'Aquila Earthquake.

BACKGROUND: Earthquakes can result in a range of psychopathology and in negative and positive consequences for survivors. OBJECTIVE: To examine the association between clinical aftereffects (anxiety and depressive symptoms) and post-traumatic growth (PTG) among young survivors of the 2009 L'Aquila earthquake, Italy. METHOD: 316 young earthquake survivors enrolled in the University of L'Aquila were evaluated two years after the natural disaster. Participants completed three main questionnaires, including Patient Health Questionnaire-9 items (PHQ-9), Self-Rating Anxiety Scale (SAS), and Posttraumatic Growth Inventory (PTGI). RESULTS: 59.6% of the student sample showed different levels of depression, whereas 13.3% reported anxiety symptoms. In both clinical dimensions (anxiety and depression), gender differences were found: female gender was confirmed risk factor for a clinical post-traumatic response. Personal PTG, demonstrated by 18% of the L'Aquila youths included in our sample, was predicted by moderate levels of depression (O.R. 2.7). In our model, gender, age, and anxiety did not show any predictive value. CONCLUSION: In a post-traumatic setting, the development of individual cognitive strategies is crucial, whereas after a natural disaster, paradoxically, a moderate depressive condition and the related distress could promote the drive to overcome the psychological consequences of the traumatic event.

Adjustment to cancer: exploring patients' experiences of participating in a psychodramatic group intervention.

The main purpose of the present study was to understand the subjective experience of patients adjusting to cancer by focusing on how that experience might be affected by participating in a psychodramatic group intervention. In-depth interviews using an interpretative-phenomenological approach were conducted with eight cancer patients involved in a psychodrama group. Four key themes were identified: (1) outside and inside relationships; (2) identities: nurturing other selves; (3) a feelings' gym: performing the internal world; and (4) many ends: mourning death and dying. Participation in cancer group using a psychodramatic approach provided positive results. In detail, the group setting: (1) favoured relationships in which it was possible to freely express oneself and (2) empowered patients in their feelings of being able to give and receive help; the psychodramatic approach: (1) supported the physical mobilisation of sense of agency and (2) permitted to deal with the grieving process. Cancer healthcare pathways would benefit from psychotherapeutic programmes using a similar approach, since psychodrama by actively involving body seems to works on areas that are often underwhelmed by other approaches, such as (i.e., physical mobilisation, body engagement, grieving adjustment). Psychodrama supports patients to achieve insights into their own possibilities to actively participate in their own life situations despite having cancer and undergoing treatment for it.

PTSD Growth and Substance Abuse Among a College Student Community: Coping Strategies after 2009 L'aquila Earthquake.

Aim of the study was the assessment of coping strategies, specifically substance use and post-traumatic growth (PTG), in 411 college students two years after 2009 L'Aquila earthquake. Post-Traumatic Growth Inventory (PTGI) was used to assess PTG and one question about substance use (alcohol, tobacco, cannabis) was asked to verify if students had modified their use in the post-earthquake compared with the pre-earthquake period. The 77.1% of college students were exposed to L'Aquila earthquake. The PTGI mean score was 35.23, underlining low positive coping strategies among student community. About substance abuse, the 43.8% of college students reported a marked increase in alcohol use, 7.8% in cannabis and the 15.8% reported an increase in nicotine use in the post-earthquake period. Despite these data, 12.5 % of the students reported a decrease in alcohol use after the earthquake and 17.3% of the sample reported a PTG, showing positive behaviors and attitudes after the traumatic experience of the natural disaster (increase of social relationships, appreciation of new future possibilities, and development of a new deep meaning of life). Inferential analysis shows a strong negative correlation between direct earthquake exposure and PTGI total score. In post-disaster settings, a systematic framework of case identification, triage, and mental health interventions, including the improvement of positive coping strategies, like the PTG, should be integrated into emergency medicine and trauma care responses.

The chemistry and parent material of urban soils in Bristol (UK): implications for contaminated land assessment.

An earlier survey of topsoil from parks and allotment in the city of Bristol (UK) revealed the presence of relatively high levels of "pseudo-total" Cd, As, Cu, Pb and Zn, with Cd and As exceeding present UK soil guidelines. This follow-up work aimed at (1) estimating geochemical thresholds for these elements based on "near-total" soil, bedrock and sediment heavy metals and (2) determining the genetic relationship between soil and bedrock using rare earth elements (REEs or lanthanides) as tracers. "Near-total" concentration of 34 elements (Al, Ca, Fe, K, Mg, Na, As, Ba, Cd, Cr, Cu, Li, Mn, Ni, P, Pb, Sc, Ti, V, Zn, Y and the rare earth elements Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sm, Tb, Yb) were obtained by ICP-MS and ICP-OES. The results show that the soil composition is largely controlled by the soil parent material, though extreme outliers are indicative of contamination at a few sites of parkland and allotments. Cumulative frequency plots show the presence of different data sets for which separate "background" values should be determined. The REE data provide evidence that weathering of the underlying sandstone was a determinant factor leading to the relatively high heavy metal enrichment found in soil samples and sediments. Reference to UK soil guidelines to decide on possible remediation measures could be very misleading due to the natural high background levels of some elements in the underlying bedrock. Before defining land as "contaminated", a thorough geochemical investigation is required at local scale in order to produce a more realistic and correct environmental assessment.

[MALDI-TOF and SELDI-TOF analysis: "tandem" techniques to identify potential biomarker in fibromyalgia]. / MALDI-TOF e SELDI-TOF: due tecniche "tandem" per l'individuazione di potenziali biomarker nella fibromialgia.

OBJECTIVE: Fibromyalgia (FM) is characterized by the presence of chronic widespread pain throughout the musculoskeletal system and diffuse tenderness. Unfortunately, no laboratory tests have been appropriately validated for FM and correlated with the subsets and activity. The aim of this study was to apply a proteomic technique in saliva of FM patients: the Surface Enhance Laser Desorption/Ionization Time-of-Flight (SELDI-TOF). METHODS: For this study, 57 FM patients and 35 HC patients were enrolled. The proteomic analysis of saliva was carried out using SELDI-TOF. The analysis was performed using different chip arrays with different characteristics of binding. The statistical analysis was performed using cluster analysis and the difference between two groups was underlined using Student's t-test. RESULTS: Spectra analysis highlighted the presence of several peaks differently expressed in FM patients compared with controls. The preliminary results obtained by SELDI-TOF analysis were compared with those obtained in our previous study performed on whole saliva of FM patients by using electrophoresis. The m/z of two peaks, increased in FM patients, seem to overlap well with the molecular weight of calgranulin A and C and Rho GDP-dissociation inhibitor 2, which we had found up-regulated in our previous study. CONCLUSION: These preliminary results showed the possibility of identifying potential salivary biomarker through salivary proteomic analysis with MALDI-TOF and SELDI-TOF in FM patients. The peaks observed allow us to focus on some of the particular pathogenic aspects of FM, the oxidative stress which contradistinguishes this condition, the involvement of proteins related to the cytoskeletal arrangements, and central sensibilization.

French adaptation of the "Frenchay Dysarthria Assessment 2" speech intelligibility test.

OBJECTIVES: Speech intelligibility can be defined as "the degree to which a speaker's intended message is recovered by a listener". Loss of intelligibility is one of the most frequent complaints in patients suffering from speech disorder, impairing communication. Measurement of intelligibility is therefore an important parameter in follow-up. We developed a French version of the "Frenchay Dysarthria Assessment, 2nd edition" (FDA-2), an intelligibility test recognized internationally in its English version. The present study details the construction of the test and its preliminary validation. MATERIALS AND METHODS: We first compiled a set of words and phrases in French, based on the criteria defined in FDA-2. In a second step, we validated the test in healthy subjects in normal and noisy conditions, to check sensitivity to speech signal degradation. RESULTS: The test proved valid and sensitive, as scores were significantly lower for noise-degraded stimuli. CONCLUSION: This French-language intelligibility test can be used to evaluate speech disorder: for example, in dysarthria, head and neck cancer or after cochlear implantation.

Developmental care, neonatal behavior and postnatal maternal depressive symptomatology predict internalizing problems at 18 months for very preterm children.

OBJECTIVE: To provide a prospective developmental model for behavioral outcomes in preterm infants in relation to developmental care (DC) practices and postnatal maternal depression. STUDY DESIGN: A longitudinal, multicenter, follow-up study conducted in 25 Italian tertiary neonatal intensive care units (NICUs). Participants were 162 healthy very preterm infants and their mothers. The level of quality of DC was assessed for each hospital. Infant's neurobehavioral profile was evaluated twice: at discharge (T1) and at 18 months for behavioral problems (T3). Maternal depressive symptomatology was measured at T1 and at 6 months (T2). RESULTS: Low-quality DC in NICUs was associated with lower levels of infant neurobehavioral adaptability and higher levels of maternal depressive symptoms. Maternal depressive symptomatology in conjunction with higher infant dysregulation predicted more internalizing problems at 18 months of age. CONCLUSION: DC interventions and postnatal maternal depression, as well as infant behavior have an impact on short- and long-term infant outcomes.

Proteomic analysis of human thyroid fine needle aspiration fluid.

The aim of this study was to determine the protein pattern of human thyroid fine needle aspiration fluid (FNA) using a proteomic approach. FNA proteins were separated using 2-dimensional gel electrophoresis (2DE), digested and then analyzed by peptide mass fingerprinting. For the first time, we provided an image of the protein components of the FNA, in which approximately 220 protein spots can be identified. The proteome analysis revealed a specific fingerprint of FNA with proteins appertaining to various functional systems. Our preliminary results of FNA protein pattern could be a starting point in studying the presence of potential markers implicated in thyroid diseases.

A Novel Panel of Serum Biomarkers for MPM Diagnosis.

Exposure to asbestos is the main cause of malignant pleural mesothelioma (MPM), a highly aggressive cancer of the pleura. Since the only tools for early detection are based on radiological tests, some authors focused on serum markers (i.e., mesothelin). The aim of this study was the evaluation of new serum biomarkers to be used individually or in combination, in order to improve the outcome of patients whose disease would be diagnosed at an earlier stage. Serum and plasma were available from 43 subjects previously exposed to asbestos and 27 MPM patients, all being epithelioid type. All the new markers found differentially expressed in MPM and healthy subjects, by proteomic and genomic approaches, have been validated in the serum by the use of specific ELISA. The combined approach, using tools of genomics and proteomics, is found to be highly innovative for this type of disease and led to the identification of new serum markers in the diagnosis of MPM. These results, if confirmed in a larger series, may have a strong impact in this area, because early detection of this cancer in people at high risk could significantly improve the course of the disease and the clinical approach to an individualized therapy.

Peripheral benzodiazepine receptors on platelets of fibromyalgic patients.

OBJECTIVE: The aim of the present study was to analyze if alterations of peripheral-type benzodiazepine receptor (PBR) characteristics occurred in platelet membranes of patients affected by primary fibromyalgia (FM). DESIGN AND METHODS: Platelets were obtained from 30 patients with FM. Evaluation of kinetic parameters of PBR was performed using [(3)H] PK11195 as specific radioligand compared with 16 healthy volunteers. RESULTS: The results showed a significant increase of PBR binding sites value in platelet membranes from FM patients (B(max) was 5366+/-188 fmol/mg vs. controls, 4193+/-341 fmol/mg, mean+/-SEM) (**p<0.01) but not for affinity value (K(d) was 4.90+/-0.39 nM vs. controls, 4.74+/-0.39 nM, mean+/-SEM) (p>0.05). Symptom severity scores (pain and tiredness) were positively correlated with B(max). CONCLUSIONS: Our results showed an up-regulation of PBR in platelets of FM patients, and this seems to be related to the severity of fibromyalgic symptoms.

Language outcomes at 36 months in prematurely born children is associated with the quality of developmental care in NICUs.

OBJECTIVE: The aim of this study was to examine the relationship between the quality levels of NICU developmental care (DC) and language skills at 36 months in very preterm (VPT) children. STUDY DESIGN: Language skills of 78 VPT children from 19 NICUs and 90 full-term controls was assessed using a standardized language test. We compared children' language task performance by splitting NICUs into units with high- and low-quality of DC according to two main factors: (1) infant centered care (ICC), and (2) infant pain management (IPM). RESULTS: VPT children from low-care units with respect to ICC obtained lower scores in sentence comprehension, compared to children from high-care units. No differences were found between preterm children from high-quality ICC NICUs and full-term children. CONCLUSIONS: Findings suggest that higher quality of DC related to infant centered care can mitigate delays in language skills at 36 months in children born VPT.

Bottom-up proteomics suggests an association between differential expression of mitochondrial proteins and chronic fatigue syndrome.

Chronic fatigue syndrome (CFS) is a debilitating and complex disorder characterized by unexplained fatigue not improved by rest. An area of investigation is the likely connection of CFS with defective mitochondrial function. In a previous work, we investigated the proteomic salivary profile in a couple of monozygotic twins discordant for CFS. Following this work, we analyzed mitochondrial proteins in the same couple of twins. Nano-liquid chromatography electrospray ionization mass spectrometry (nano-LC-MS) was used to study the mitochondria extracted from platelets of the twins. Subsequently, we selected three proteins that were validated using western blot analysis in a big cohort of subjects (n=45 CFS; n=45 healthy), using whole saliva (WS). The selected proteins were as follows: aconitate hydratase (ACON), ATP synthase subunit beta (ATPB) and malate dehydrogenase (MDHM). Results for ATPB and ACON confirmed their upregulation in CFS. However, the MDHM alteration was not confirmed. Thereafter, seeing the great variability of clinical features of CFS patients, we decided to analyze the expression of our proteins after splitting patients according to clinical parameters. For each marker, the values were actually higher in the group of patients who had clinical features similar to the ill twin. In conclusion, these results suggest that our potential markers could be one of the criteria to be taken into account for helping in diagnosis. Furthermore, the identification of biomarkers present in particular subgroups of CFS patients may help in shedding light upon the complex entity of CFS. Moreover, it could help in developing tailored treatments.

Role of cysteine residues of rat A2a adenosine receptors in agonist binding.

In the present study, we investigated the role of disulfide bridges and sulfhydryl groups in A2a adenosine receptor binding of the agonist 2-p-(2-carboxyethyl)phenylethylamino)-5'-N-ethylcarboxamidoadenosi ne (CGS 21680). To evaluate the presence of essential disulfide bridges, rat striatal membranes were incubated with [3H]CGS 21680 in the presence of dithiothreitol and binding of the agonist to membranes was measured. The amount of [3H]CGS 21680 which specifically bound, decreased progressively upon pretreatment of membranes with increasing concentrations of dithiothreitol. Pretreatment of rat striatal membranes with 12.5 mM dithiothreitol for 15 min at 25 degrees C resulted in a 2-fold decrease of A2a adenosine receptor affinity for [3H]CGS 21680, and a reduction in the maximal number of binding sites. The presence of agonist or antagonist ligands protected the A2a adenosine receptor sites from the effect of dithiothreitol. We also examined the susceptibility of A2a adenosine receptors to inactivation by the sulfhydryl alkylating reagent, N-ethylmaleimide. When rat striatal membranes were pretreated with N-ethylmaleimide for 30 minutes at 37 degrees C, a decrease in specific [3H]CGS 21680 binding was observed. Pretreatment of membranes with 1 mM N-ethylmaleimide also resulted in a 2-fold reduction of A2a adenosine receptor affinity for [3H]CGS 21680, as well as a slight decrease in the maximal number of binding sites. Neither agonist nor antagonist ligands were effective in protecting the receptor sites from inactivation by N-ethylmaleimide. In contrast, addition of 100 microM guanosine-5'-O-(3-thiotriphosphate) or 5'-guanylylimidodiphosphate were both effective in protecting the receptor sites from inactivation by N-ethylmaleimide. This protective effect was significant but not complete. Our data suggest that disulfide bridges play a role in the structural integrity of the A2a adenosine receptor, furthermore, reduced sulfhydryl groups appear to be important but we do not yet know if they are on the receptor or on the Gs alpha subunit.

Incidence of antibodies blocking thyrotropin effect in vitro in patients with euthyroid or hypothyroid autoimmune thyroiditis.

Autoantibodies blocking the TSH-dependent production of cAMP in thyroid cells (TSH-BAb) have been described in atrophic thyroiditis (AT; idiopathic myxedema) and in neonates with transient hypothyroidism, but their incidence in autoimmune thyroiditis in relation to thyroid status remains to be completely established. To this purpose TSH-BAb were evaluated in a group of 140 consecutive patients with autoimmune thyroiditis, which included 26 cases of AT and 114 subjects with goitrous Hashimoto's thyroiditis (HT); among the goitrous group 27 were euthyroid (HT-E), 32 had subclinical hypothyroidism (HT-SH), and 55 had clinical hypothyroidism (HT-H). TSH-BAb were measured in immunoglobulin G prepared by DEAE-Sephadex A-50 by determining their ability to inhibit TSH-dependent cAMP production in a differentiated strain of cultured rat thyroid cells (FRTL-5). Using this sensitive and reproducible method, TSH-BAb were detected in 12 of 26 (46%) patients with AT, in 1 of 27 (3.7%) subjects with HT-E, in 3 of 32 (9.4%) with HT-SH, and in 20 of 55 (36%) with HT-H. The prevalence of TSH-BAb was higher in AT vs. HT-H (P less than 0.001), HT-SH (P less than 0.001), or HT-E (P less than 0.001), and in HT-H vs. HT-SH (P less than 0.001) or HT-E (P less than 0.001). Mean TSH-BAb levels in AT were higher than those in HT-H (P less than 0.005) and HT-SH (P less than 0.025); the difference was not significant between HT-H and HT-SH. An inverse correlation was found between TSH-BAb levels and estimated goiter weight (P less than 0.005). The results of the present study indicate that 1) in autoimmune thyroiditis TSH-BAb are detectable almost exclusively in hypothyroid patients, their prevalence being higher in overt hypothyroidism than in subclinical thyroid failure; 2) the prevalence of TSH-BAb and their mean levels are higher in hypothyroid patients with AT than in those with HT; and 3) therefore, the presence of circulating TSH-BAb appears to be related to the development of hypothyroidism and thyroid atrophy.

Structure-activity relationships of 1,2,4-triazolo[1,5-a] quinoxalines and their 1-deaza analogues imidazo[1,2-a]quinoxalines at the benzodiazepine receptor.

The synthesis, BZR binding activity, and GABA ratio of some 1,2,4-triazolo[1,5-a]quinoxalines and imidazo[1,2-a]quinoxalines are reported. Both series of compounds displayed similar affinities while their efficacies were different. The structure-activity relationships have provided the opportunity to localize on the BZR accessory areas which are able to enhance the affinity and evaluate the importance of the presence or absence of a proton acceptor atom to determine different trends of efficacy.

Suc-[Glu9,Ala11,15]-endothelin-1 (8-21), IRL 1620, identifies two populations of ET(B) receptors in guinea-pig bronchus.

The pharmacological properties of endothelin receptors (ETR) were investigated in guinea-pig bronchus by comparing binding and functional results. In binding assays, both the ET(B) agonists, endothelin-3 (ET-3) and N-suc-[Glu9,Ala11,15]ET-1(8-21) (IRL 1620), and the antagonist, N-cis-2,6-dimethylpiperidinocarbonyl-L-gamma-methylleucyl-D- 1-methoxycarbonyltryptophanyl-D-norleucine (BQ 788), showed biphasic inhibition curves of [125I]-endothelin-1 (ET-1) binding to bronchus membranes prepared from intact or epithelium-deprived tissue. IRL 1620 did not completely displace specifically [125I]-ET-1 bound to these tissue preparations. In the presence of the ET(A)-selective antagonist, cyclo(-D-Trp-D-Asp-L-Pro-D-Val-L-Leu) (BQ 123, 1 microM), IRL 1620 displacement curves were shallow but a complete inhibition was reached at a concentration of 1 microM. Both curves were better represented by two-site models. In addition, BQ 788 competition curves became monophasic when binding experiments were performed in the presence of 1 microM BQ 123. The non-selective agonist, ET-1, and BQ 123 inhibited [125I]-ET binding to bronchus membranes in dose-dependent fashions with monophasic curves. The contracting activity of IRL 1620 (0.55 nM- 1.6 microM) was tested on multiple-ring bronchial preparations pretreated with peptidase and cyclo-oxygenase inhibitors. BQ 788 shifted IRL1620 concentration-response curves to the right while BQ 123 did not influence bronchial responsiveness. In addition, a potentiation of the maximal response to the agonist was observed in BQ 788 treated bronchial rings. This effect was abolished by tissue pretreatment with Nomega-nitro-L-argininemethylester (L-NAME) or epithelium removal but not by pretreatment with atropine or iberiotoxin. Our results demonstrate that guinea-pig bronchus contains two populations of ET(B) receptors with different affinities for the ET(B)-selective agonist, IRL 1620. One ET(B) receptor population appears to activate bronchial muscle contraction while another on epithelial cells causes muscle relaxation through the release of nitric oxide (NO).

Characterization of peripheral-type benzodiazepine binding sites from rat and pig pancreas.

The binding of [3H]1-(2-chlorophenyl-N-methyl-1-methyl-propyl)-3-isoquinolinecarboxa mide ([3H]PK-11195) and [3H]7-chloro-1,3-dihydro-1-methyl-5-(p-chlorophenyl)-2H-1,4-benzodiaz epin-2 - on ([3H]Ro5-4864) to membrane preparations of pancreas was studied in the rat and pig. [3H]PK-11195 bound with high affinity to rat and pig membrane preparations yielding maximal numbers of binding sites (Bmax) of 2393 +/- 160 and 777 +/- 65 fmol/mg of protein, respectively, and equilibrium dissociation constant (Kd) values of 3.01 +/- 0.25 and 3.9 +/- 0.23 nM, respectively. [3H]Ro5-4864 successfully labelled rat but not pig pancreatic membranes, yielding a Kd value of 6.45 +/- 0.5 nM and a Bmax value of 551 +/- 43 fmol/mg of protein. Displacement studies showed a similar rank order of potency of various unlabelled ligands against both [3H]Ro5-4864 and [3H]PK-11195 binding to rat and pig membrane preparations (PK-11195 > or = Ro5-4864 > diazepam > flunitrazepam >> flumazenil). These results suggest that [3H]PK-11195 binds with high affinity and specificity to rat and pig pancreas and [3H]Ro5-4864 binds with high affinity and specificity to rat but not pig pancreas.

Characterization of peripheral benzodiazepine receptors in purified large mammal pancreatic islets.

In this work, we evaluated the biochemical properties of peripheral benzodiazepine receptors (PBRs) in the porcine endocrine pancreas and their role in insulin release. Binding of [3H]1-(2-chlorophenyl-N-methyl-1-methyl-propyl)-3-isoquinolinecarboxa mide ([3H]PK-11195), a specific ligand of PBRs, to islet membranes was saturable and Scatchard's analysis of saturation curve demonstrated the presence of a single population of binding sites, with a dissociation constant (Kd) value of 4.75 +/- 0.70 nM and a maximum amount of specifically bound ligand (Bmax) of 4505 +/- 502 fmol/mg of proteins. The pharmacological profile of PBRs was determined as the ability of PK-11195 and several benzodiazepine compounds to displace [3H]PK-11195 from these binding sites. The rank order of potency yielded the following affinity results: PK-11195 > 7-chloro-1,3-dihydro-1-methyl-5-(p-chlorophenyl)-2H-1,4-benzodiazepine-2 -on (Ro 5-4864) > diazepam > or = flunitrazepam >> flumazenil. Secretion studies demonstrated that PK-11195 (1 and 10 microM) and Ro 5-4864 (10 and 50 microM) significantly potentiated insulin secretion from freshly isolated porcine islets at 3.3 mM glucose. This potentiating effect was not observed at 16.7 mM glucose concentration nor by the addition of clonazepam. These results show the presence of PBRs in purified porcine pancreatic islets and suggest an implication of PBRs in the mechanisms of insulin release.

Regulation of agonist binding to rat ET(B) receptors by cations and GTPgammaS.

Endothelins exert their physiological effects through interaction with cell surface receptors that are members of the G-protein-coupled receptor family. The endothelin receptor subtype B (ET(B) receptor) is abundantly expressed in rat cerebellum. Since agonist binding to G-protein-coupled receptors may be modulated by cations and guanine nucleotides, we investigated the effects of cations and guanosine 5'-O-(2-thiotriphosphate) (GTPgammaS) on 125I-endothelin-1 (125I-ET-1) binding to rat cerebellar membranes. Both Na+ and Mg2+-stimulated 125I-ET-1 binding causing an increase in receptor affinity for the agonist. While the effect of the divalent cation was evident at relatively low concentrations (5-10 mM), the stimulatory activity of the monovalent cation appeared at relatively high concentrations (50 mM). Additive activities of 25-50 mM NaCl and 1 mM MgCl2 suggested that monovalent and divalent cations increased receptor affinity for ET-1 by different mechanisms. In the presence of 5 mM MgCl2, 50 mM NaCl caused an additional modest reduction of the Kd value. Whereas 5 mM MgCl2 affected the displacement curves of both ET-3 and suc-[Glu9, Ala11,15]-endothelin-1 (8-21) (IRL 1620), the influence of 50 mM NaCl on these curves was less substantial. All together, these results suggest that modulation of receptor affinity by NaCl depends on the nature of the displacing agonist. In the presence of 5 mM MgCl2 or 50 mM NaCl, a partial regulation of 125I-ET-1 binding by GTPgammaS was detectable, while in the absence of cations no GTPgammaS-dependent inhibition was evident.

3 alpha-hydroxy-5 alpha-pregnan-20-one modulation of solubilized GABA/benzodiazepine receptor complex.

The allosteric modulation of the progesterone metabolite 3 alpha- hydroxy-5 alpha-pregnan-20-one (DHP) on [3H]Flunitrazepam and [35S]t-butylbicyclophosphorothionate (TBPS) binding was investigated on a soluble receptor preparation. Better results in the solubilization occurred by the use of the zwitterionic detergent CHAPS with the inclusion of the phospholipid asolectin: this treatment was found suitable to study the steroidal modulation on [3H]Flunitrazepam and [35S]TBPS binding. We found that DHP was able to enhance [3H]Flunitrazepam binding in the presence of Cl- ions, while [35S]TBPS binding was inhibited by DHP. Scatchard analysis of specific [35S]TBPS and [3H]Flunitrazepam binding yielded in a single straight line both in the controls and in the presence of the hormone; DHP increased the apparent affinity of [3H]Flunitrazepam binding without altering the apparent Bmax value. In the case of [35S]TBPS, DHP decreased the apparent Bmax value whereas the Kd value remained nearly the same.