Discovery of a Potent and Orally Bioavailable Cyclophilin Inhibitor Derived from the Sanglifehrin Macrocycle

Cyclophilins are a family of peptidyl-prolyl isomerases that are implicated in a wide range of diseases including hepatitis C. Our aim was to discover through total synthesis an orally bioavailable, non-immunosuppressive cyclophilin (Cyp) inhibitor with potent anti-hepatitis C virus (HCV) activity that could serve as part of an all oral antiviral combination therapy. An initial lead 2 derived from the sanglifehrin A macrocycle was optimized using structure based design to produce a potent and orally bioavailable inhibitor 3. The macrocycle ring size was reduced by one atom, and an internal hydrogen bond drove improved permeability and drug-like properties. 3 demonstrates potent Cyp inhibition ( K_d = 5 nM), potent anti-HCV 2a activity (EC₅₀ = 98 nM), and high oral bioavailability in rat (100%) and dog (55%). The synthetic accessibility and properties of 3 support its potential as an anti-HCV agent and for interrogating the role of Cyp inhibition in a variety of diseases.

Predictors of early dropout in treatment for gambling disorder: The role of personality disorders and clinical syndromes

Several treatment options for gambling disorder (GD) have been tested in recent years; however dropout levels still remain high. This study aims to evaluate whether the presence of psychiatric comorbidities predicts treatment outcome according to Millon's evolutionary theory, following a six-month therapy for GD. The role of severity, duration of the disorder, typology of gambling (mainly online or offline) and pharmacological treatment were also analysed. The recruitment included 194 pathological gamblers (PGs) to be compared with 78 healthy controls (HCs). Psychological assessment included the South Oaks Gambling Screen and the Millon Clinical Multiaxial Inventory-III. The "treatment failure" group (n = 70) comprised PGs who prematurely dropped out of the treatment whereas the "abstinent group" (n = 124) included PGs who completed the treatment regardless of whether the outcome was successful or not. As expected, the presence of psychiatric comorbidities was highlighted as a significant predictor in dropping out of the therapy. Specifically negativistic personality disorder, antisocial personality disorder, drug dependence and PTSD were associated with early dropout. These variables were predictive of treatment outcome independently from the typology of gambling, severity, duration of the disorder and pharmacological treatment. Implications for psychological and psychiatric care are discussed.

Impulsivity and Stress Response in Pathological Gamblers During the Trier Social Stress Test

Gambling has been associated with increased sympathetic nervous system output and stimulation of the hypothalamic–pituitary–adrenal axis. However it is unclear how these systems are affected in pathological gambling. This study aimed to investigate the effect of the Trier Social Stress Test (TSST) on cortisol and on cardiac interbeat intervals in relation to impulsivity, in a sample of male pathological gamblers compared to healthy controls. In addition, we investigated the correlation between the TSST, duration of the disorder and impulsivity. A total of 35 pathological gamblers and 30 healthy controls, ranging from 19 to 58 years old and all male, participated in this study. Stress response was measured during and after the TSST by salivary cortisol and cardiac interbeat intervals; impulsivity was assessed with the Barratt Impulsiveness Scale (BIS-11). Exposure to the TSST produced a significant increase in salivary cortisol and interbeat intervals in both groups, without differences between groups. We found a negative correlation between baseline cortisol and duration of pathological gambling indicating that the longer the duration of the disorder the lower the baseline cortisol levels. Additionally, we found a main effect of impulsivity across groups on interbeat interval during the TSST, indicating an association between impulsivity and the intensity of the neurovegetative stress response during the TSST. Involvement of the hypothalamic–pituitary–adrenal axis in pathological gambling was confirmed together with evidence of a correlation between length of the disorder and diminished baseline cortisol levels. Impulsivity emerged as a personality trait expressed by pathological gamblers; however the neurovegetative response to the TSST, although associated with impulsivity, appeared to be independent of the presence of pathological gambling.

Mutations in adenosine deaminase-like (ADAL) protein confer resistance to the antiproliferative agents N6-cyclopropyl-PMEDAP and GS-9219

BACKGROUND/AIM

GS 9219 is a double prodrug of antiproliferative nucleotide analog 9-(2-Phosphonylmethoxyethyl)guanine (PMEG), with potent in vivo efficacy against various hematological malignancies. This study investigates the role of adenosine deaminase-like (ADAL) protein in the intracellular activation of GS-9219.

MATERIALS AND METHODS

A cell line resistant to 9-(2-Phosphonylmethoxyethyl)-N(6)-cyclopropyl-2,6-diaminopurine (cPrPMEDAP), an intermediate metabolite of GS-9219, was generated and characterized.

RESULTS

The resistant cell line was cross-resistant to cPrPMEDAP and GS-9219, due to a defect in the deamination of cPrPMEDAP to PMEG. Mutations in the ADAL gene (H286R and S180N) were identified in the resistant cells that adversely-affected its enzymatic activity. Introduction of the wild-type ADAL gene re-sensitized resistant cells to both cPrPMEDAP and GS-9219.

CONCLUSION

The ADAL protein plays an essential role in the intracellular activation of GS-9219 by catalyzing the deamination of cPrPMEDAP metabolite to PMEG. Mutations affecting the activity of ADAL confer resistance to both GS-9219 and its metabolite cPrPMEDAP.

Synthesis and biological evaluation of phosphonate analogues of nevirapine

A series of nevirapine-based analogues containing the phosphonate functionality were prepared and evaluated in vitro against HIV RT. The effect of the phosphonate was evaluated against the wild type and Y181C HIV replication. An in vivo PK study was performed on a select analogue.

[Analysis of clinical-surgical course of neonates with long-gap esophageal atresia during their spontaneous growth]

INTRODUCTION

Esophageal atresia (EA) is one of the most prevalent surgical conditions in the newborn. Sometimes early oesophageal anastomosis can't be done due to the esophageal gap. Long gap (LG) definition is not precise. Although consensus exist about conservation of owns esophagus is the best therapeutic option, literature is not clear about how long and under what circunstances is advisable to wait for the spontaneous esophageal pouches to growth (P. Puri approach). Furthermore at present we don't even know the real repercussion that this waiting can implicate.

OBJECTIVE

The aim of the study was to evaluate the clinical and surgical outcome of newborns with EALG during their stay in a neonatal intensive care unit (NICU) at a third level children's hospital.

MATERIALS AND METHODS

We retrospectively reviewed the charts of all newborn with EA admitted in the NICU from January 2002 to December 2006 in order to analyze sex, gestacional age, weight, type of EA, LG, respiratory and surgical complications, length of stay and mortality.

RESULTS

During the study time period 64 newborns with EAwere admitted, 21 (33%) had EALG (our population). We underwent primary repair with esophageal anastomosis in 8 newborns at 80 +/- 40 days. All of them had gastroesophageal reflux, 50% presented different complications such as anastomotic leak, stricture and mediastinal infections. 13 patients required an esophagostomy at a mean age of 46 +/- 34 days due to a lack of growth of esophageal's pouches and/or serious respiratory complications. There were no deaths.

CONCLUSIONS

There were high percentages of esophagostomized patients. The result of waiting for the primary repair was a high number of children with chronic lung disease and a high rate of serious complications. Esophageal anastomosis were accompanied by long hospital stays and no clear benefits. The early application of dynamic esophageal lengthening should be explored as an alternative strategy for newborns with EALG.

Design of electrical stimulation bioreactors for cardiac tissue engineering

Electrical stimulation has been shown to improve functional assembly of cardiomyocytes in vitro for cardiac tissue engineering. Carbon electrodes were found in past studies to have the best current injection characteristics. The goal of this study was to develop rational experimental design principles for the electrodes and stimulation regime, in particular electrode configuration, electrode ageing, and stimulation amplitude. Carbon rod electrodes were compared via electrochemical impedance spectroscopy (EIS) and we identified a safety range of 0 to 8 V/cm by comparing excitation thresholds and maximum capture rates for neonatal rat cardiomyocytes cultured with electrical stimulation. We conclude with recommendations for studies involving carbon electrodes for cardiac tissue engineering.

Perinatal exposure to 5-metoxytryptamine, behavioural-stress reactivity and functional response of 5-HT1A receptors in the adolescent rat

Serotonin is involved in a wide range of physiological and patho-physiological mechanisms. In particular, 5-HT1A receptors are proposed to mediate stress-adaptation. The aim of this research was to investigate in adolescent rats: first, the consequences of perinatal exposure to 5-metoxytryptamine (5MT), a 5-HT1/5-HT2 serotonergic agonist, on behavioural-stress reactivity in elevated plus maze, open field and forced swim tests; secondly, whether the behavioural effects induced by perinatal exposure to 5MT on open field and forced swim tests were affected by the selective 5-HT1A receptor agonist LY 228729, a compound able to elicit a characteristic set of motor behaviours on these experimental models, and by the co-administration of the selective and silent 5-HT1A antagonist WAY 100635. Results indicate that a single daily injection of 5MT to, pregnant dams from gestational days 12 to 21 (1mg/kg s.c.), and to the pups from postnatal days 2 to 18 (0.5mg kg s.c.), induce in the adolescent rat offspring: an increase in the percentage of entries and time spent on the open arms in the elevated plus maze; a reduction in locomotor activity and rearing frequency, and an increase in the time spent on the central areas in the open field test; a decrease in immobility and an increase in swimming in the forced swim test. Acute administration of LY 228729 (1.5mg/kg s.c.) strongly decreases rearing frequency and increases peripheral activity in the open field test, and decreases immobility and increases swimming in the forced swim test both in perinatally vehicle and 5MT-exposed offspring. Co-administration of WAY 100635 (0.25mg/kg s.c.) abolishes the effects exerted by LY 228729. These results suggest that, in the adolescent rat, perinatal exposure to 5MT enhances the stress-related adaptive behavioural responses, presumably through a predominant action on presynaptic 5-HT1A receptors and does not deteriorate the functional response of 5-HT1A receptors to selective agonist and antagonist compounds.

Biomimetic approach to cardiac tissue engineering

Here, we review an approach to tissue engineering of functional myocardium that is biomimetic in nature, as it involves the use of culture systems designed to recapitulate some aspects of the actual in vivo environment. To mimic the capillary network, subpopulations of neonatal rat heart cells were cultured on a highly porous elastomer scaffold with a parallel array of channels perfused with culture medium. To mimic oxygen supply by haemoglobin, the culture medium was supplemented with a perfluorocarbon (PFC) emulsion. Constructs cultivated in the presence of PFC contained higher amounts of DNA and cardiac markers and had significantly better contractile properties than control constructs cultured without PFC. To induce synchronous contractions of cultured constructs, electrical signals mimicking those in native heart were applied. Over only 8 days of cultivation, electrical stimulation induced cell alignment and coupling, markedly increased the amplitude of synchronous construct contractions and resulted in a remarkable level of ultrastructural organization. The biomimetic approach is discussed in the overall context of cardiac tissue engineering, and the possibility to engineer functional human cardiac grafts based on human stem cells.

Presynaptic effects of anandamide and WIN55,212-2 on glutamatergic nerve endings isolated from rat hippocampus

We examined the effects of the endocannabinoide-anandamide (AEA), the synthetic cannabinoid, WIN55,212-2, and the active phorbol ester, 4-beta-phorbol 12-myristate 13-acetate (4-beta-PMA), on the release of [(3)H]d-Aspartate ([(3)H]d-ASP) from rat hippocampal synaptosomes. Release was evoked with three different stimuli: (1) KCl-induced membrane depolarization, which activates voltage-dependent Ca(2+) channels and causes limited neurotransmitter exocytosis, presumably from ready-releasable vesicles docked in the active zone; (2) exposure to the Ca(2+) ionophore-A23187, which causes more extensive transmitter release, presumably from intracellular reserve vesicles; and (3) K(+) channel blockade by 4-aminopyridine (4-AP), which generates repetitive depolarization that stimulates release from both ready-releasable and reserve vesicles. AEA produced concentration-dependent inhibition of [(3)H]d-ASP release stimulated with 15 mM KCl (E(max)=47.4+/-2.8; EC(50)=0.8 microM) but potentiated the release induced by 4-AP (1mM) (+22.0+/-1.3% at 1 microM) and by A23187 (1 microM) (+98.0+/-5.9% at 1 microM). AEA's enhancement of the [(3)H]d-ASP release induced by the Ca(2+) ionophore was mimicked by 4-beta-PMA, which is known to activate protein kinase C (PKC), and the increases produced by both compounds were completely reversed by synaptosome treatment with staurosporine (1 microM), a potent PKC blocker. In contrast, WIN55,212-2 inhibited the release of [(3)H]d-ASP evoked by KCl (E(max)=47.1+/-2.8; EC(50)=0.9 microM) and that produced by 4-AP (-26.0+/-1.5% at 1 microM) and had no significant effect of the release induced by Ca(2+) ionophore treatment. AEA thus appears to exert a dual effect on hippocampal glutamatergic nerve terminals. It inhibits release from ready-releasable vesicles and potentiates the release observed during high-frequency stimulation, which also involves the reserve vesicles. The latter effect is mediated by PKC. These findings reveal novel effects of AEA on glutamatergic nerve terminals and demonstrate that the effects of endogenous and synthetic cannabinoids are not always identical.

Reversal of prenatal diazepam-induced deficit in a spatial-object learning task by brief, periodic maternal separation in adult rats

In the rat, prenatal exposure to diazepam (DZ) induces a permanent reduction in GABA/BZ receptor (R) function and behavioural abnormalities. Environmental modifications during early stages of life can influence brain development and induce neurobiological and behavioural changes throughout adulthood. Indeed, a subtle, periodic, postnatal manipulation increases GABA/BZ R activity and produces facilitatory effects on neuroendocrine and behavioural responses. We here investigated the impact of prenatal treatment with DZ on learning performance in adult 3- and 8-month-old male rats and the influence of a brief, periodic maternal separation on the effects exerted by prenatal DZ exposure. Learning performance was examined employing a non-aversive spatial, visual and/or tactile task, the "Can test". Behavioural reactivity, emotional state and fear/anxiety-driven behaviour were also examined using open field (OF), acoustic startle reflex (ASR) and elevated plus-maze (EPM) tests. A single daily injection of DZ (1.5mg/kg, s.c.), over gestational days (GD) 14-20, induced, in an age-independent manner, a severe deficit in learning performance, a decrease in locomotor and explorative activity and an increase in peak amplitude in the ASR. Furthermore, anxiety-driven behaviour in EPM was disrupted. Daily maternal separation for 15 min over postnatal days 2-21 exerted opposite effects in all the paradigms examined. Prenatally DZ-exposed maternal separated rats, in contrast to respective non-separated rats, showed an improvement in learning performance, a decrease in emotionality and a normalization of the exploratory behaviour in EPM. These results suggest that a greater maternal care, induced by separation, can serve as a source for the developing brain to enhance neuronal plasticity and to prevent the behavioural abnormalities induced by prenatal DZ exposure.

Inhibition by anandamide and synthetic cannabimimetics of the release of [3H]D-aspartate and [3H]GABA from synaptosomes isolated from the rat hippocampus

Cannabinoids (CB) can act as retrograde synaptic mediators of depolarization-induced suppression of inhibition or excitation in hippocampus. This mechanism may underlie the impairment of some cognitive processes produced by these compounds, including short-term memory formation in the hippocampus. In this study, we investigated several compounds known to interact with CB receptors, evaluating their effects on K(+)-evoked release of [3H]D-aspartate ([3H]D-ASP) and [3H]GABA from superfused synaptosomes isolated from the rat hippocampus. [3H]D-ASP and [3H]GABA release were inhibited to different degrees by the synthetic cannabinoids WIN 55,212-2; CP 55,940, and arachidonyl-2'-chloroethylamide/N-(2-chloroethyl)-5Z,8Z,11Z,14Z-eicosatetraenamide (ACEA), as well as by the endocannabinoids, anandamide (AEA), and 2-arachidonoylglycerol (2-AG). Both types of release were also inhibited by capsaicin. The inhibition produced by each of the cannabinoid compounds and capsaicin was unaffected by capsazepine or by the CB1-receptor antagonists AM-251 and SR141716A. The mechanism underlying AEA- and synthetic CB-induced inhibition of the release of [3H]GABA and [3H]D-ASP from rat hippocampal synaptosomes might not involve activation of presynaptic CB1 receptors.

Know-how and know-why in biochemical engineering

This contribution analyzes the position of biochemical engineering in general and bioprocess engineering particularly in the force fields between fundamental science and applications, and between academia and industry. By using culture technology as an example, it can be shown that bioprocess engineering has moved slowly but steadily from an empirical art concerned with mainly know-how to a science elucidating the know-why of culture behavior. Highly powerful monitoring tools enable biochemical engineers to understand and explain quantitatively the activity of cellular culture on a metabolic basis. Among these monitoring tools are not just semi-online analyses of culture broth by HPLC, GC and FIA, but, increasingly, also noninvasive methods such as midrange IR, Raman and capacitance spectroscopy, as well as online calorimetry. The detailed and quantitative insight into the metabolome and the fluxome that bioprocess engineers are establishing offers an unprecedented opportunity for building bridges between molecular biology and engineering biosciences. Thus, one of the major tasks of biochemical engineering sciences is not developing new know-how for industrial applications, but elucidating the know-why in biochemical engineering by conducting research on the underlying scientific fundamentals.

Effects of 8-OH-DPAT on open field performance of young and aged rats prenatally exposed to diazepam: a tool to reveal 5-HT1A receptor function

Central GABAergic and serotoninergic systems interact with one another and are implicated in controlling different behaviours. A gentle early long-lasting handling can prevent the deficits in locomotion and exploration in open field (O.F.) in 3-month-old male rats prenatally exposed to diazepam (DZ). Purpose of this study was to extend the research to older handled rats prenatally exposed to DZ and to assess the activity of 5-HT1A receptors (Rs), evaluating the performance in O.F. at 3 and 18 months of age following 8-OH-DPAT administration. A single daily s.c. injection of DZ (1.5 mg/kg) from gestation day 14 to gestation day 20 induced in aged, but not in young rats, a decrease in total distance travelled (TDT) and in rearing frequency (RF) and an increase of transitions from the periphery to the centre of the arena (CNT) and in the time spent in the centre of the arena (CAT), compared to controls. 8-OH-DPAT (0.150 mg/kg s.c.), given 1 h before testing, increased TDT and decreased RF, CNT and CAT in both vehicle- and DZ-exposed young rats. In aged rats prenatally exposed to DZ, 8-OH-DPAT induced an increase in TDT and a slight decrease in RF, CNT and CAT. These findings indicate that the effects of handling and of 8-OH-DPAT in prenatally DZ-exposed rats are age-dependent and suggest that O.F. test can represent a valid tool to identify the changes in 5-HT1A Rs activity following drug treatment.

Alterations in striatal neuropeptide mRNA produced by repeated administration of L-DOPA, ropinirole or bromocriptine correlate with dyskinesia induction in MPTP-treated common marmosets

Chronic administration of L-DOPA to MPTP-treated common marmosets induces marked dyskinesia while repeated administration of equivalent antiparkisonian doses of ropinirole and bromocriptine produces only mild involuntary movements. The occurrence of dyskinesia has been associated with an altered balance between the direct and indirect striatal output pathways. Using in situ hybridisation histochemistry, we now compare the effects of these drug treatments on striatal preproenkephalin-A (PPE-A) and adenosine A(2a) receptor mRNA expression as markers of the indirect pathway and striatal preprotachykinin (PPT) mRNA and preproenkephalin-B (PPE-B, prodynorphin) mRNA expression as markers of the direct pathway.The equivalent marked losses of specific [3H]mazindol binding in the striatum of all drug treatment groups confirmed the identical nature of the nigral cell loss produced by MPTP treatment. MPTP-induced destruction of the nigro-striatal pathway markedly increased the level of PPE-A mRNA in the caudate nucleus and putamen and decreased the levels of PPT and PPE-B mRNA relative to normal animals. Repeated treatment with L-DOPA for 30 days produced marked dyskinesia but had no effect on the MPTP-induced increase in PPE-A mRNA in the caudate nucleus and putamen. In contrast, L-DOPA treatment normalised the MPTP-induced decrease in the level of PPT and PPE-B mRNA. Repeated treatment with ropinirole produced little or no dyskinesia but markedly reversed the MPTP-induced elevation in PPE-A mRNA in the caudate nucleus and putamen. However, it had no effect on the decrease in PPT or PPE-B mRNA. Similarly, bromocriptine treatment which induced only mild dyskinesia attenuated the MPTP-induced elevation in PPE-A mRNA in the caudate nucleus and putamen with no effect on reduced striatal PPT or PPE-B mRNA. Neither MPTP treatment nor treatment with L-DOPA, bromocriptine or ropinirole had any effect on adenosine A(2a) receptor mRNA in the striatum. These patterns of alteration in striatal PPE-A and PPT and PPE-B mRNA produced by L-DOPA, bromocriptine and ropinirole show differential involvement of markers of the direct and indirect striatal output pathways related to improvement of locomotor activity and mirror the relative abilities of the drugs to induce dyskinesia.

Prevalence of headache in patients with Behçet's disease without overt neurological involvement

The aims of the present study were to evaluate the prevalence of headache and the frequency of different headache syndromes in patients with Behçet's Disease (BD) without neurological involvement and to investigate the relationship with other clinical, and behavioural variables. Twenty-seven BD patients and 27 control subjects underwent a validated semistructured questionnaire based on the International Headache Society criteria. Levels of anxiety and depression, disease activity, and current medication were collected. Headache occurred in 88.9% of BD patients. There was no difference in the prevalence of the different headache syndromes between BD patients and controls. Only migraine without aura (MwA) was significantly more frequent in BD patients than controls (44.4% vs. 11.1%, respectively, P= 0.013). No relationship was found between MwA and clinical, and behavioural variables. Among headache syndromes, MwA showed the highest frequency in BD. A vascular or neuronal subclinical dysfunction could justify this association. A careful interview for migraine might be included in the diagnostic work-up of BD.

Benign prostatic hyperplasia: correlations between receptor density and binding affinity of alpha(1)-adrenoceptors and several clinical parameters

The aim of the study was to determine whether relations do exist between the concentration and activity of alpha(1)-adrenoceptors, both inside the prostatic adenoma and the periurethral zone corresponding to the bladder neck, and clinical and biological parameters such as symptoms, evaluated by the American Urological Association (AUA) score, age, weight of the prostate, PSA, and the flow rate. Twenty patients with symptomatic benign prostatic hyperplasia were selected for an open prostatectomy. One gram of tissue was dissected from inside the adenoma and 1 g from the periurethral zone corresponding to the bladder neck. The alpha(1)-adrenoceptors were evaluated for the apparent dissociation constant (K(d)) and the maximal number of binding sites (B(max)). A correlation seems to exist between receptor density inside the adenoma and the bladder neck and an inverse correlation between receptor density and the AUA total symptoms score. Finally, a highly significant difference was found in patients with an AUA score of <15 or >15. No relationship was found between receptor binding affinity and the considered clinical parameters.

6-Hydroxydopamine lesioning differentially affects alpha-synuclein mRNA expression in the nucleus accumbens, striatum and substantia nigra of adult rats

The effect of a unilateral 6-hydroxydopamine (6-OHDA) lesion and/or repeated administration of levodopa (L-DOPA) to normal and 6-OHDA-lesioned rats on alpha-synuclein mRNA expression was investigated by in situ hybridization histochemistry. A 6-OHDA lesion of the nigro-striatal pathway alone, confirmed by the loss of nigral tyrosine hydroxylase mRNA expression, markedly decreased alpha-synuclein mRNA in the lesioned substantia nigra (SN). In contrast, the levels of alpha-synuclein mRNA in the denervated striatum and nucleus accumbens were not altered. Chronic administration of L-DOPA to normal or 6-OHDA-lesioned rats had no effect on alpha-synuclein mRNA expression in the SN, striatum or nucleus accumbens. These data confirm that alpha-synuclein is localized in the nigro-striatal tract but that its gene expression is not regulated by dopamine.

Long-lasting handling affects behavioural reactivity in adult rats of both sexes prenatally exposed to diazepam

Environmental stressors can substantially affect the adaptive response of rats to novelty in a sexually dimorphic manner. Gender-related differences are also observed in neurochemical and behavioural patterns of adult rats following prenatal exposure to diazepam (DZ). In the present study the behavioural reactivity to novelty is investigated in open field (OF) and in acoustic startle reflex (ASR) tests, in non handled (NH), short-lasting handled (SLH) and long-lasting handled (LLH) adult male and female rats prenatally exposed to DZ. A single daily s.c. injection of DZ (1.5 mg/kg) over gestation days 14-20 decreases GABA/BDZ receptor function in both sexes, as shown by the decreased electrographic hippocampal response to DZ and the increased response to picrotoxin, after intra-locus coeruleus injection of the two compounds. In OF NH DZ-exposed males display a lower total distance travelled (TDT), a higher rearing frequency (RF) and a greater number of transitions in the centre of the arena (CNT) compared to NH rats prenatally exposed to vehicle. Conversely, NH DZ-exposed females show slight changes in TDT and RF and a greater reduction in CNT and in the amount of time spent in the centre of the arena (CAT). These effects are associated with an increase in the peak amplitude of the ASR in both sexes. Short-lasting handling slightly influences DZ-evoked effects in animals of both sexes. In DZ-exposed males long-lasting handling attenuates the reduction in TDT and the enhancement in RF, prevents the increase in CNT and reduces the peak amplitude of ASR. In DZ-exposed females, long-lasting handling increases TDT and RF, induces a lower avoidance of the centre of the arena, and does not modify the peak amplitude of ASR, when compared to controls. These findings indicate that prenatal exposure to DZ differently affects behavioural reactivity in adult male and female rats, and suggest that a long-lasting handling is able to attenuate some behavioural deficits induced by prenatal DZ exposure.

GDNF reverses priming for dyskinesia in MPTP-treated, L-DOPA-primed common marmosets

Parkinson's disease (PD) is associated with a progressive loss of dopamine neurons in the substantia nigra and degeneration of dopaminergic terminals in the striatum. Although L-DOPA treatment provides the most effective symptomatic relief for PD it does not prevent the progression of the disease, and its long-term use is associated with the onset of dyskinesia. In rodent and primate studies, glial cell line-derived neurotrophic factor (GDNF) may prevent 6-OHDA- or MPTP-induced nigral degeneration and so may be beneficial in the treatment of PD. In this study, we investigate the effects of GDNF on the expression of dyskinesia in L-DOPA-primed MPTP-treated common marmosets, exhibiting dyskinesia. GDNF or saline was administered by two intraventricular injections, 4 weeks apart, to MPTP-treated, L-DOPA-treated common marmosets primed to exhibit dyskinesia. Prior to GDNF or saline administration, all animals displayed marked dyskinesia when treated with L-DOPA. GDNF administration produced a significant improvement in motor disability and, following the second injection of GDNF, a significant improvement in the locomotor activity was observed. Following the administration of L-DOPA there was a greater reversal of disability and a reduction in the intensity of L-DOPA-induced dyskinesia in GDNF-treated animals compared to saline-treated controls. However, there was no significant difference in L-DOPA's ability to increase locomotor activity between GDNF-treated and saline-treated animals. GDNF treatment caused a significant increase in the number of tyrosine hydroxylase-positive neurons in the substantia nigra, but no change in [(3)H]mazindol binding to dopamine terminals was found in the striatum of GDNF-treated animals compared to saline-treated controls. In GDNF-treated animals a small but significant reduction in enkephalin mRNA was observed in the caudate nucleus but not in the putamen or the nucleus accumbens. Substance P mRNA expression was equally reduced in the caudate nucleus and the putamen of the GDNF-treated animals but not in the nucleus accumbens. Intraventricular administration of GDNF improved MPTP-induced disability and reversed dopamine cell loss in the substantia nigra. GDNF also diminished L-DOPA-induced dyskinesia, which may relate to its ability to partly restore nigral dopaminergic transmission or to modify the activity of striatal output pathways.

Serotonergic modulation of rat pineal gland activity: in vivo evidence for a 5-Hydroxytryptamine(2C) receptor involvement

There are some suggestions that, in the pineal gland, serotonin acts not only as a precursor of melatonin but also plays a role in the modulation of the pineal biosynthetic activity. To corroborate this possible neuromodulatory role of 5-hydroxytryptamine (serotonin) (5-HT) on the pineal gland, the effects of two 5-HT(2) receptor agonists meta-chlorophenylpiperazine (m-CPP) and 1-(2, 5-dimethoxy-4-iodophenyl)-2-aminopropane were assessed in vivo on pineal N-acetyltransferase (NAT) activity and melatonin content in rats. m-CPP potentiated the enhancement of NAT activity and pineal melatonin content induced by isoproterenol administration during daytime, whereas it did not affect the diurnal basal biosynthetic activity of the gland. At night, m-CPP and 1-(2, 5-dimethoxy-4-iodophenyl)-2-aminopropane enhanced significantly the physiological increases in both pineal NAT activity and melatonin content. This enhancement was prevented by pretreatment with N-(1-methyl-5-indolyl)-N'-(3-pyridyl) urea hydrochloride, an antagonist with higher affinity for 5-HT(2B/C) than for 5-HT(2A) receptor, as well as by pretreatment with 8-[5-(2, 4-dimethoxy-5-(4-trifluoromethyl-phenylsulphonamido)-phenyl-5-o xopent hyl]-1,3,8-triazospiro[4,5]decane-2,4-dione, the most specific 5-HT(2C) receptor now available, but not by pretreatment with ketanserin, an antagonist with higher affinity for 5-HT(2A) than for 5-HT(2C) receptor. These results suggest that 5-HT(2C) receptors are likely involved in the mediation of the serotonergic modulation of pineal biosynthetic activity in rats.

Chronic L-DOPA treatment increases striatal cannabinoid CB1 receptor mRNA expression in 6-hydroxydopamine-lesioned rats

The effect of a unilateral 6-hydroxydopamine (6-OHDA) lesion of the left medial forebrain bundle and 3 weeks treatment with L-DOPA of normal and 6-OHDA lesioned rats on CB1r mRNA expression was investigated by in situ hybridization. A 6-OHDA lesion of nigrostriatal pathway alone, confirmed by the loss of nigral tyrosine hydroxylase mRNA, did not alter CB1r mRNA levels in the dopamine depleted striatum. Similarly, chronic L-DOPA treatment of normal rats had no effect on striatal CB1r mRNA expression. In contrast, chronic L-DOPA treatment of 6-OHDA-lesioned rats significantly increased CB1r mRNA expression in the denervated striatum. These results suggest that the CB1r activity may be altered by L-DOPA's action and this may be related to the treatment of Parkinson's disease.

Intrathoracic alimentary tract duplication cysts treated in utero by thoracoamniotic shunting

Alimentary tract duplication cysts are rarely diagnosed in utero. We report two fetal patients that presented with intrathoracic alimentary tract duplication cysts, mediastinal shift and hydrops. In one fetus, the cyst continued into the fetal abdomen and pelvis through a left diaphragmatic hernia. Despite successful ultrasound-guided needle aspirations in both fetuses, there was rapid reaccumulation of the fluid and recurrence of the mediastinal shift, prompting the placement of a thoracoamniotic shunt. In one fetus, there was rapid resolution of the mediastinal shift with the disappearance of the hydrops within 2 weeks. The second fetus suffered an intrauterine demise 2 days after the shunt placement. Postnatal resection in the surviving infant revealed a large cyst consistent with an intrathoracic duplication of the stomach. The autopsy of the second fetus revealed an intrathoracic duplication cyst of the stomach and proximal small intestine.

Effects of nitric oxide donors on basal and K+-evoked release of [3H]noradrenaline from rat cerebral cortex synaptosomes

We investigated the effects of nitric oxide (NO) donors, S-nitroso-N-acetylpenicillamine and sodium nitroprusside on basal and K+-evoked release of [3H]noradrenaline from superfused synaptosomes from the rat cerebral cortex. Both substances produced concentration-dependent increases in the release of the labeled transmitter under basal and depolarized conditions. The effects of the donors on basal release were Ca2+-independent but were not inhibited by the carrier-uptake blocker, desipramine; the effects were abolished by hemoglobin (an NO scavenger). Thirty-five minutes after stimulation with sodium nitroprusside, the synaptosomes were still responsive to KCl stimulation, indicating that the donor's effects were not caused by damage to the synaptosome membrane. The cGMP analogue, 8-bromo-cGMP, had no effect on basal release, and the enhanced release produced by sodium nitroprusside was not inhibited by the specific inhibitor of soluble guanylate cyclase, 1H-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one, indicating that NO's effects on basal release of the neurotransmitter are guanylate cyclase-independent. Both of the NO donors had more marked effects on release of [3H]noradrenaline during K+-stimulated depolarization. The NO-mediated increase in this case was partially antagonized by 10 microM LH-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one, and 8-Br-cGMP was also capable of producing concentration-dependent increases in the K+-stimulated release of the transmitter. These findings indicate that the effects of the NO donors on [3H]noradrenaline release during depolarization are partially mediated by the activation of guanylate cyclase.

Locomotor and antidepressant-like effects of 5-HT(1A) agonist LY 228729 in prenatally benzodiazepine-exposed rats

Locomotor activity and antidepressant-like effect in the forced swim test (FST) of 5-HT(1A) agonist LY 228729 were investigated in adult rats prenatally exposed at doses of diazepam (DZ) and alprazolam (ALP) which induce persistent downregulation of GABA/ benzodiazepine (BZ) receptors. Prenatal exposure to ALP and DZ did not modify the efficacy of subchronic LY 228729 to decrease immobility time in the FST. Prenatal DZ and ALP potentiated the facilitatory effect of subchronic LY 228729 on locomotor activity; prenatal DZ was more effective than prenatal ALP. Moreover, prenatal DZ increased stereotypic movements induced by LY 228729. These data suggest that the persistent downregulation of GABA/BZ receptors, induced by prenatal BZs, does not play a role in the anti-immobility effect in the FST of 5-HT(1A) agonist LY 228729 while it can increase locomotor activity and stereotypic movements. Moreover, this study indicates that increases in locomotor activity do not seem to influence the anti-immobility effect in the FST of LY 228729 in rats.

Extracellular sodium removal increases release of neuropeptide Y-like immunoreactivity from rat brain hypothalamic synaptosomes: involvement of intracellular acidification

Rat hypothalamic synaptosomes were exposed via superfusion to various stimuli and the release of neuropeptide Y-like immunoreactivity (NPY-LI) was measured by means of radioimmunoassay procedures. High KCl (15-50 mM) concentration dependently evoked NPY-LI release; the evoked overflow reached a plateau at 30 mM KCl and was abolished in the absence of Ca2+ ions. Furthermore, a remarkable NPY-LI overflow was obtained when extracellular Na+ ions were removed. Low external Na(+)-evoked NPY-LI release was independent of the presence of Ca2+ ions from the superfusion medium. It is well known that the reduction of external Na+ ions activates the release of several neurotransmitters through an inversion of the uptake-carrier working direction; but such mechanisms, involving Na(+)-dependent uptake, have never been described for neuropeptides. The alteration of the extracellular Na+ concentration is able to modify the concentration of the intracellular Ca2+ and H+ ions. In fact, the concentrations of these two ions are regulated through Na(+)-dependent exchange mechanisms across the membrane. Amiloride, blocking the Na+/H+ exchanger, was able to maintain low Na(+)-evoked NPY-LI release, underlying that the blockade of the exchanger preserves the H+ accumulation induced by the reduction of the external Na+ ions. NPY-LI release could also be stimulated by nigericine, a proton ionophore, showing that the intracellular acidification is responsible for NPY-LI release. Intracellular acidification may stimulate Ca2+ ion release from intracellular stores, as has been shown by other workers. Large dense-core vesicles containing the peptide appear to be more sensitive to local intracellular Ca2+ release compared with extracellular Ca2+ ion entry through voltage-dependent channels.

Characterization of a selective antagonist of neuropeptide Y at the Y2 receptor. Synthesis and pharmacological evaluation of a Y2 antagonist

Neuropeptide Y (NPY) is a potent inhibitor of neurotransmitter release through the Y2 receptor subtype. Specific antagonists for the Y2 receptors have not yet been described. Based on the concept of template-assembled synthetic proteins we have used a cyclic template molecule containing two beta-turn mimetics for covalent attachment of four COOH-terminal fragments RQRYNH2 (NPY 33-36), termed T4-[NPY(33-36)]4. This structurally defined template-assembled synthetic protein has been tested for binding using SK-N-MC and LN319 cell lines that express the Y1 and Y2 receptor, respectively. T4-[NPY(33-36)]4 binds to the Y2 receptor with high affinity (IC50 = 67.2 nM) and has poor binding to the Y1 receptor. This peptidomimetic tested on LN319 cells at concentrations up to 10 microM shows no inhibitory effect on forskolin-stimulated cAMP levels (IC50 for NPY = 2.5 nM). Furthermore, we used confocal microscopy to examine the NPY-induced increase in intracellular calcium in single LN319 cells. Preincubation of the cells with T4-[NPY(33-36)]4 shifted to the right the dose-response curves for intracellular mobilization of calcium induced by NPY at concentrations ranging from 0.1 nM to 10 microM. Finally, we assessed the competitive antagonistic properties of T4-[NPY(33-36)]4 at presynaptic peptidergic Y2 receptors modulating noradrenaline release. the compound T4-[NPY(33-36)]4 caused a marked shift to the right of the concentration-response curve of NPY 13-36, a Y2-selective fragment, yielding a pA2 value of 8.48. Thus, to our best knowledge, T4-[NPY(33-36)]4 represents the first potent and selective Y2 antagonist.

Behavioural responsiveness to picrotoxin and desipramine in adult rats prenatally exposed to different benzodiazepine receptor agonists

The behavioural responsiveness to picrotoxin and desipramine was investigated in adult rats prenatally exposed to different benzodiazepine receptor agonists such as diazepam, alprazolam and zolpidem. Prenatal exposure to diazepam and alprazolam similarly potentiated the anti-immobility effect on the forced swimming test and the inhibitory effect on spontaneous motor activity of picrotoxin and desipramine and increased the seizure sensitivity to picrotoxin. Prenatal zolpidem seems to be ineffective. These data suggest that, despite the differences in their pharmacodynamic profile, prenatal exposure to diazepam and alprazolam, but not zolpidem, may have similar permanent consequences on the behavioural effects of drugs acting on the GABAA receptors.

Effects of desipramine and alprazolam on forced swimming behaviour of adult rats exposed to prenatal diazepam

Pregnant rats were treated with a single daily s.c. injection of diazepam (2 mg/kg) over gestation days 14-20. This treatment led to a reduction in GABA receptor complex function since adult male offspring showed a strong decrease in electrographic hippocampal responses to alprazolam and a strongly increased response to picrotoxin after intra-locus coeruleus injection of the two compounds. No difference in immobility time in the forced swimming test and in spontaneous motor activity was observed between prenatally vehicle- and diazepam-exposed offspring. Conversely, prenatal exposure to diazepam potentiated the anti-immobility effect of subchronic desipramine (10 mg/kg i.p.) and made active a dose of desipramine (5 mg/kg i.p.) that was ineffective in prenatally vehicle-exposed rats. This effect was observed only in pretested rats. Prenatal exposure to diazepam blocked the anti-immobility effect of subchronic alprazolam (15 mg/kg i.p.) in both non-pretested and pretested rats. Spontaneous motor activity was strongly reduced in all groups. These findings suggest that a persistent reduction in GABA receptor complex function, induced by prenatal exposure to diazepam, does not alter the mobility of adult progeny in the forced swimming test, but it may have consequences when drugs acting on the GABA receptor complex are used.

NMDA-GABA interactions in an animal model of behaviour: a gating mechanism from motivation toward psychotic-like symptoms

We studied the effects of desipramine, alprazolam, muscimol and dizocilpine (MK-801) (alone or associated with desipramine) in the forced swimming test in rats after long-lasting termination of chronic exposure to vehicle and pentylenetetrazol. Sensitisation with pentylenetetrazol was ineffective in changing immobility time in the forced swimming test compared to vehicle treatment; pentylenetetrazol enhanced the anti-immobility effect of desipramine, abolished the anti-immobility effect of alprazolam and did not affect the anti-immobility effect of muscimol. MK-801 at the dose that did not modify immobility time in vehicle-treated rats and in pentylenetetrazol-treated animals strongly potentiated the anti-immobility effect of desipramine in pentylenetetrazol-treated rats. MK-801 in association with desipramine induced a marked hyperlocomotion and hyperexcitability, with swaying movements and oral stereotypies in pentylenetetrazol-sensitised rats. Results are considered the experimental representation of a 'gating mechanism' toward psychotic-like symptoms.

Effects of desipramine and alprazolam in the forced swim test in rats after long-lasting termination of chronic exposure to picrotoxin and pentylenetetrazol

Rats were treated for 5 weeks with three subconvulsant doses of picrotoxin (PTX) and pentylenetetrazol (PTZ) per week to induce a persistent reduction of the GABAA receptor function which results in chemical kindling. Fifteen days after termination of this treatment schedule, the effect of desipramine (DMI) and alprazolam (ALP) on immobility time in the forced swim test (FST) was evaluated. Chronic PTX and PTZ did not alter the immobility time. Acute PTX and PTZ reduced the immobility of rats chronically treated with vehicle but not of those exposed chronically to PTX and PTZ. Chronic PTX did not influence the anti-immobility effect of DMI, but blocked that of ALP. Chronic PTZ markedly potentiated the anti-immobility effect of DMI but blocked that of ALP. Concomitant administration of chlordiazepoxide prevented the effects of chronic PTX and PTZ. These findings suggest that a long-lasting reduction in GABAA receptor function, unlike acute reduction, does not play an important role in the mobility of rats in the FST and in the anti-immobility effect of DMI while it blocks that of ALP.

Changes in the rat brain 5-HT1A and 5-HT2 receptors after chronic administration of levoprotiline, (+)-oxaprotiline and other antidepressant drugs

The effects of levoprotiline (LEV), a (-)-enantiomer of oxaprotiline (OXA) and a clinically effective antidepressant, on the binding parameters of hippocampal 5-HT1A and cortical 5-HT2 receptors of rats were compared with those of (+)-enantiomer of OXA ((+)-OXA), imipramine and mianserin. Both LEV and (+)-OXA displayed in vitro some affinity for 5-HT1A receptors labelled with [3H]-8-OH-DPAT, and for 5-HT2 receptors labelled with [3H]-ketanserin. Repeated administration of LEV, for 14 days led to a marked increase in the number of 5-HT1A binding sites in the rat hippocampus, with no change in the KD values. (+)-OXA, imipramine and mianserin produced similar effects on 5-HT1A binding parameters. The number of 5-HT2 receptors was increased after two weeks of LEV administration, not altered after (+)-OXA, and decreased after imipramine or mianserin. The number of [3H]-ketanserin binding sites was decreased after four weeks of (+)-OXA administration, but not altered after LEV. The specific binding of [3H]-ketanserin in the rat cerebral cortex was decreased after repeated treatment with LEV and (+)-OXA (ex vivo). In competition studies the affinity of serotonin for [3H]-ketanserin binding sites was decreased in LEV- and increased in (+)-OXA-treated rats. The results suggest that LEV similarly to other antidepressants increases the number of 5-HT1A receptors, however without common alteration in 5-HT2 receptor number and function.

Antidepressant and anxiolytic effects of alprazolam versus the conventional. antidepressant desipramine and the anxiolytic diazepam in the forced swim test in rats

The antidepressant and anxiolytic effects of alprazolam were compared to those of desipramine, diazepam and buspirone in the forced swim test. Subchronic alprazolam induced a reduction in immobility similar to that of desipramine in 'non-pretested' and 'pretested' rats. In 'non-pretested' rats, the anti-immobility effect of desipramine was potentiated by diazepam and alprazolam, given before subchronic desipramine, while the anti-immobility effect of subchronic alprazolam was counteracted by diazepam. Diazepam, administered before the pretest session, counteracted, 24 h later, the anti-immobility effect of subchronic desipramine and alprazolam; alprazolam counteracted the anti-immobility effect of alprazolam but not of desipramine, buspirone at the highest doses tested potentiated the anti-immobility effect of subchronic desipramine but not of alprazolam. These data provide further support for the hypothesis that the GABA/benzodiazepine/Cl complex is directly implicated in the action of antidepressants and that systems other than the GABA system are involved in the antidepressant and anxiolytic effects of alprazolam.