Atrial fibrillation: Epigenetic aspects and role of sodium-glucose cotransporter 2 inhibitors.

Atrial fibrillation (AF) is the most frequent arrhythmia and is associated with substantial morbidity and mortality. Pathophysiological aspects consist in the activation of pro-fibrotic signaling and Ca2+ handling abnormalities at atrial level. Structural and electrical remodeling creates a substrate for AF by triggering conduction abnormalities and cardiac arrhythmias. The care of AF patients focuses predominantly on anticoagulation, symptoms control and the management of risk factors and comorbidities. The goal of AF therapy points to restore sinus rhythm, re-establish atrioventricular synchrony and improve atrial contribution to the stroke volume. New layer of information to better comprehend AF pathophysiology, and identify targets for novel pharmacological interventions consists of the epigenetic phenomena including, among others, DNA methylation, histone modifications and noncoding RNAs. Moreover, the benefits of sodium-glucose cotransporter 2 inhibitors (SGLT2i) in diabetic and non-diabetic patients at cardiovascular risk as well as emerging evidence on the ability of SGLT2i to modify epigenetic signature in cardiovascular diseases provide a solid background to investigate a possible role of this drug class in the onset and progression of AF. In this review, following a summary of pathophysiology and management, epigenetic mechanisms in AF and the potential of sodium-glucose SGLT2i in AF patients are discussed.

Similar programmed death ligand 1 (PD-L1) expression profile in patients with mild COPD and lung cancer.

Programmed Death Ligand 1 (PD-L1) is crucial in regulating the immunological tolerance in non-small cell lung cancer (NSCLC). Alveolar macrophage (AM)-derived PD-L1 binds to its receptor, PD-1, on surveilling lymphocytes, leading to lymphocyte exhaustion. Increased PD-L1 expression is associated with cigarette smoke (CS)-exposure. However, the PD-L1 role in CS-associated lung diseases associated with NSCLC, such as chronic obstructive pulmonary disease (COPD), is still unclear. In two different cohorts of ever smokers with COPD or NSCLC, and ever and never smoker controls, we evaluated PD-L1 expression: (1) via cutting-edge digital spatial proteomic and transcriptomic profiling (Geomx) of formalin-fixed paraffin-embedded (FFPE) lung tissue sections (n = 19); and (2) via triple immunofluorescence staining of bronchoalveolar lavage (BAL) AMs (n = 83). PD-L1 mRNA expression was also quantified in BAL AMs exposed to CS extract. PD-L1 expression was increased in the bronchiolar wall, parenchyma, and vascular wall from mild-moderate (GOLD 1-2) COPD patients compared to severe-very severe (GOLD 3-4) COPD patients and controls. Within all the COPD patients, PD-L1 protein expression was associated with upregulation of genes involved in tumor progression and downregulation of oncosuppressive genes, and strongly directly correlated with the FEV1% predicted, indicating higher PD-L1 expression in the milder vs. more severe COPD stages. In bronchioles, PD-L1 levels were strongly directly correlated with the number of functionally active AMs. In BAL, we confirmed that AMs from patients with both GOLD 1-2 COPD and NSCLC had the highest and similar, PD-L1 expression levels versus all the other groups, independently from active cigarette smoking. Intriguingly, AMs from patients with more severe COPD had reduced AM PD-L1 expression compared to patients with mild COPD. Acute CS extract stimulation increased PD-L1 mRNA expression only in never-and not in ever-smoker AMs. Lungs from patients with mild COPD and NSCLC are characterized by a similar strong PD-L1 expression signature in bronchioles and functionally active AMs compared to patients with severe COPD and controls. Active smoking does not affect PD-L1 levels. These observations represent a new resource in understanding the innate immune mechanisms underlying the link between COPD and lung cancer onset and progression and pave the way to future studies focused on the mechanisms by which CS promotes tumorigenesis and COPD.

New and old roles of the peripheral and brain renin-angiotensin-aldosterone system (RAAS): Focus on cardiovascular and neurological diseases.

It is commonly accepted that the renin-angiotensin-aldosterone system (RAAS) is a cardiovascular circulating hormonal system that plays also an important role in the modulation of several patterns in the brain. The pathway of the RAAS can be divided into two classes: the traditional pathway of RAAS, also named classic RAAS, and the non-classic RAAS. Both pathways play a role in both cardiovascular and neurological diseases through a peripheral or central control. In this regard, renewed interest is growing in the last years for the consideration that the brain RAAS could represent a new important therapeutic target to regulate not only the blood pressure via central nervous control, but also neurological diseases. However, the development of compounds able to cross the blood-brain barrier and to act on the brain RAAS is challenging, especially if the metabolic stability and the half-life are taken into consideration. To date, two drug classes (aminopeptidase type A inhibitors and angiotensin IV analogues) acting on the brain RAAS are in development in pre-clinical or clinical stages. In this article, we will present an overview of the biological functions played by peripheral and brain classic and non-classic pathways of the RAAS in several clinical conditions, focusing on the brain RAAS and on the new pharmacological targets of the RAAS.

Atenolol vs enalapril in young hypertensive patients after successful repair of aortic coarctation.

Late arterial hypertension has been identified as a major predictor for morbidity and mortality in aortic coarctation (AoC) patients. Few data are available about efficacy and tolerability of angiotensin converting enzyme inhibitors vs beta-blockers in young AoC patients. This study aimed to evaluate the tolerability and efficacy on 24-h blood pressure (BP) and left ventricular mass/height(2.7) (LVMI), of atenolol vs enalapril. We enrolled consecutive AoC hypertensive patients with (a) no history of BP treatment or after >48 h of withdrawn, (b) aged 6-20 years, (c) body mass index (BMI) <90th percentile for age and sex, (d) >12 months from a successful AoC repair and (e) no major associated cardiovascular abnormalities. All patient were evaluated with 24-h ambulatory BP monitoring, standard echocardiography, strain-strain rate imaging, at enrolment, 3, 6 and 12 months of treatment. We studied 51 AoC patients (13±3.9 years, BMI: 21.4±4.3 kg m(-2)). Patients were randomly assigned at atenolol treatment (n=26), or enalapril treatment (n=25). The mean follow-up duration was 11±2 months. Both drugs were able to significantly reduce 24-systolic BP (SBP; atenolol: 133±11 mm Hg vs 124±16 mm Hg, P=0.016; enalapril: 135±6 mm Hg vs 127±7 mm Hg, P=0.001). Only enalapril was able to significantly reduce LVMI (47±12 vs 39.6±10 g m(-)(2.7), P=0.016). Only in atenolol group in two cases (7.7%) drug withdrawal was needed because of adverse events. Enalapril and atenolol are similarly effective in reducing SBP. However, only enalapril demonstrated a significant reduction of LVMI. In no case, enalapril was stopped because of adverse events.

Cytokines and VEGF induction in orthodontic movement in animal models.

Orthodontics is a branch of dentistry that aims at the resolution of dental malocclusions. The specialist carries out the treatment using intraoral or extraoral orthodontic appliances that require forces of a given load level to obtain a tooth movement in a certain direction in dental arches. Orthodontic tooth movement is dependent on efficient remodeling of periodontal ligament and alveolar bone, correlated with several biological and mechanical responses of the tissues surrounding the teeth. A periodontal ligament placed under pressure will result in bone resorption whereas a periodontal ligament under tension results in bone formation. In the primary stage of the application of orthodontic forces, an acute inflammation occurs in periodontium. Several proinflammatory cytokines are produced by immune-competent cells migrating by means of dilated capillaries. In this paper we summarize, also through the utilization of animal models, the role of some of these molecules, namely, interleukin-1ß and vascular endothelial growth factor, that are some proliferation markers of osteoclasts and osteoblasts, and the macrophage colony stimulating factor.

Intrinsic resistance to selumetinib, a selective inhibitor of MEK1/2, by cAMP-dependent protein kinase A activation in human lung and colorectal cancer cells.

BACKGROUND: MEK is activated in ∼40% colorectal cancer (CRC) and 20-30% non-small cell lung cancer (NSCLC). Selumetinib is a selective inhibitor of MEK1/2, which is currently in clinical development. METHODS: We evaluated the effects of selumetinib in vitro and in vivo in CRC and NSCLC cell lines to identify cancer cell characteristics correlating with sensitivity to MEK inhibition. RESULTS: Five NSCLC and six CRC cell lines were treated with selumetinib and classified according to the median inhibitory concentration (IC(50)) values as sensitive (≤1 µM) or resistant (>1 µM). In selumetinib-sensitive cancer cell lines, selumetinib treatment induced G1 cell-cycle arrest and apoptosis and suppression of tumour growth as xenografts in immunodeficient mice. Evaluation of intracellular effector proteins and analysis of gene mutations showed no correlation with selumetinib sensitivity. Microarray gene expression profiles revealed that the activation of cAMP-dependent protein kinase A (PKA) was associated with MEK inhibitor resistance. Combined targeting of both MEK and PKA resulted in cancer cell growth inhibition of MEK inhibitor-resistant cancer cell lines in vitro and in vivo. CONCLUSION: This study provides molecular insights to explain resistance to an MEK inhibitor in human cancer cell lines.

Antitumour efficacy of MEK inhibitors in human lung cancer cells and their derivatives with acquired resistance to different tyrosine kinase inhibitors.

BACKGROUND: To study the molecular mechanisms regulating cancer cell resistance to four different tyrosine kinase inhibitors (TKIs): erlotinib, gefitinib, vandetanib and sorafenib. METHODS: An in vitro model of acquired resistance to these TKIs was developed by continuously treating the human lung adenocarcinoma cell line CALU-3 with escalating doses of each drug. Transcriptional profiling was performed with Agilent whole genome microarrays. Western blot analysis, enzyme-linked immunosorbent (ELISA), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell proliferation, migration, invasion and anchorage-independent colony growth assays were conducted in vitro and experiments with established xenografts in athymic nude mice were performed in vivo in parental (P) and TKI-resistant (R) CALU-3 cell lines. RESULTS: As compared with P-CALU-3 cells, in TKI-R CALU-3 cell lines a significant increase in the expression of activated, phosphorylated MET, IGF-1R, AKT, MEK, MAPK and of survivin was observed. Downregulation of E-cadherin and amphiregulin mRNAs and upregulation of vimentin, VE-cadherin, HIF-1α and vascular endothelial growth factor receptor-1 mRNAs were observed in all four TKI-R CALU-3 cell lines. All four TKI-R CALU-3 cells showed increased invasion, migration and anchorage-independent growth. Together, these data suggest epithelial to mesenchymal transition (EMT) in TKI-R CALU-3 cells. Treatment with several agents that target AKT, MET or IGF-1R did not affect TKI-R CALU-3 cell proliferation. In contrast, treatment with MSC19363669B and selumetinib, two selective MEK inhibitors, caused inhibition of cell proliferation, invasion, migration, anchorage-independent growth in vitro and of tumour growth in vivo of all four TKI-R CALU-3 cell lines. CONCLUSION: These data suggest that resistance to four different TKIs is characterised by EMT, which is MEK-inhibitor sensitive in human CALU-3 lung adenocarcinoma.

Relationship between A-line Autoregressive Index, Spectral Entropy and steady state predicted site-effect effective concentrations at 05-50-95 of propofol at different clinical endpoints.

AIM: Target controlled infusion intravenous anesthesia is a growing phenomenon. Nowadays, many anesthesiologists feel the need to monitor depth of anesthesia during total intravenous anesthesia, even though it is not a standard technique worldwide. Spectral Entropy (SE) is a relatively new depth of anesthesia index. The aim of this study was to investigate whether predicted site-effect propofol concentrations, A-line Autoregressive Index (AAI) and SE values are useful for predicting loss of verbal contact (LVC) and loss of consciousness (LOC) during steady-state conditions. METHODS: Forty-four patients scheduled for elective major abdominal surgery were recruited. All patients were unpremedicated. A target controlled infusion of propofol was administered using Schnider's pharmacokinetic model. The initial propofol infusion provided a site-effect concentration of 1.0 mcg mL-1, and was increased stepwise by 1.0 mcg mL-1 every 4 minutes until the concentration reached 6.0 mcg mL-1. A 4 minute interval was chosen to assure that steady state site-effect concentrations were obtained. AAI, SE and propofol site-effect concentrations were recorded when LVC occurred and also when LOC occurred. Population values for predicted site-effect concentrations at the clinical endpoints were estimated and correlated with AAI and SE values. RESULTS: In our study for LOC the effect-site concentration to include 90% of patients was 5.85 ?mcg mL-1 (5.70-5.90) and 3.4 mcg mL-1 (3.24-3.60) for LVC. In this study, 90% of patients lost verbal contact at an AAI value of 68 (64.6-71.4) and an SE value of 68.2 (66.2-70.2). LOC occurred in 90% of patients at an AAI value of 39.2 (37.2-41.1) and an SE value of 40.2 (38.1-41.3). CONCLUSIONS: LOC and LVC occur within a defined range of predicted site-effect concentrations. More emphasis should be given to site-effect concentrations. SE and AAI have similar values at different endpoints and similar correlation with Ceprop. AAI and SE are both useful tools in predicting both LVC and LOC.

Expression profiles in surgically-induced carotid stenosis: a combined transcriptomic and proteomic investigation.

Vascular injury aimed at stenosis removal induces local reactions often leading to restenosis. The aim of this study was a concerted transcriptomic-proteomics analysis of molecular variations in a model of rat carotid arteriotomy, to dissect the molecular pathways triggered by vascular surgical injury and to identify new potential anti-restenosis targets. RNA and proteins extracted from inbred Wistar Kyoro (WKY) rat carotids harvested 4 hrs, 48 hrs and 7 days after arteriotomy were analysed by Affymetrix rat microarrays and by bidimensional electrophoresis followed by liquid chromatography and tandem mass spectrometry, using as reference the RNA and the proteins extracted from uninjured rat carotids. Results were classified according to their biological function, and the most significant Kyoro Encyclopedia of Genes and Genomes (KEGG) pathways were identified. A total of 1163 mRNAs were differentially regulated in arteriotomy-injured carotids 4 hrs, 48 hrs and 7 days after injury (P < 0.0001, fold-change > or =2), while 48 spots exhibited significant changes after carotid arteriotomy (P < 0.05, fold-change > or =2). Among them, 16 spots were successfully identified and resulted to correspond to a set of 19 proteins. mRNAs were mainly involved in signal transduction, oxidative stress/inflammation and remodelling, including many new potential targets for limitation of surgically induced (re)stenosis (e.g. Arginase I, Kruppel like factors). Proteome analysis confirmed and extended the microrarray data, revealing time-dependent post-translational modifications of Hsp27, haptoglobin and contrapsin-like protease inhibitor 6, and the differential expression of proteins mainly involved in contractility. Transcriptomic and proteomic methods revealed functional categories with different preferences, related to the experimental sensitivity and to mechanisms of regulation. The comparative analysis revealed correlation between transcriptional and translational expression for 47% of identified proteins. Exceptions from this correlation confirm the complementarities of these approaches.

Relationship between bispectral index, electroencephalographic state entropy and effect-site EC50 for propofol at different clinical endpoints.

BACKGROUND: State entropy (SE) is a newly available monitor for depth of anaesthesia. We investigated whether the relationship between predicted effect-site propofol concentration and both bispectral index (BIS) and SE values is useful for predicting loss of verbal contact and loss of consciousness during steady-state conditions. METHODS: Twenty unpremedicated patients undergoing elective major abdominal surgery were recruited. A target-controlled infusion of propofol was administered using Schneider's pharmacokinetic model. The propofol infusion was set at an initial site-effect concentration of 1.0 microg ml(-1), and increased by 1.0 microg ml(-1) steps every 4 min, up to 6.0 microg ml(-1). A 4-min interval was chosen to ensure that steady-state site-effect concentrations were obtained. Propofol site-effect concentrations and BIS and SE values were recorded at loss of verbal contact (LVC) and loss of consciousness (LOC). Population values for predicted effect-site concentrations at the clinical endpoints were estimated and correlated with BIS and SE values. RESULTS: For LVC, the effect-site concentration for 90% of patients was 1.1 (1.1-3.2) microg ml(-1) and for LOC 2.8 (2.8-5.65) microg ml(-1). LVC occurred in 90% of patients at a BIS value of 70.2 (70.2-90.2) and an SE value of 60.3 (60.3-75.5) and LOC occurred at a BIS value of 38.2 (38.2-70.4) and an SE value of 42.2 (42.2-60.4). CONCLUSIONS: LVC and LOC occurred within a defined range of predicted effect-site concentrations. SE had a smaller range than BIS and higher correlation with effect-site concentration and may be more useful than BIS in predicting both LVC and LOC.

Relationship between Bispectral Index, electroencephalographic state entropy and effect-site EC50 for propofol at different clinical endpoints.

BACKGROUND: State entropy (SE) is a newly available monitor for depth of anaesthesia. We investigated whether the relationship between predicted effect-site propofol concentration and Bispectral Index (BIS) and SE values is useful for predicting loss of verbal contact and loss of consciousness during steady-state conditions. METHODS: Twenty unpremedicated patients undergoing elective major abdominal surgery were recruited. A target-controlled infusion of propofol was administered using Schneider's pharmacokinetic model. The propofol infusion was set at an initial site effect concentration of 1.0 microg ml(-1) and increased by 1.0 microg ml(-1) steps every 4 min up to 6.0 microg ml(-1). A 4-min interval was chosen to ensure that steady-state effect-site concentrations were obtained. Propofol site effect concentrations and BIS and SE values were recorded at loss of verbal contact (LVC) and loss of consciousness (LOC). Population values for predicted effect-site concentrations at the clinical endpoints were estimated and correlated with BIS and SE values. RESULTS: For LVC, the effect-site concentration for 90% of patients was 1.1 (1.1-3.2) microg ml(-1) and for LOC it was 2.8 (2.8-5.65) microg ml(-1). LVC occurred in 90% of patients at a BIS value of 70.2 (70.2-90.2) and an SE value of 60.3 (60.3-75.5), and LOC occurred at a BIS value of 38.2 (38.2-70.4) and an SE value of 42.2 (42.2-60.4). CONCLUSIONS: LVC and LOC occurred within a defined range of predicted effect-site concentrations. SE had a smaller range than BIS and greater correlation with effect-site concentration and may be more useful than BIS in predicting both LVC and LOC.

Antibiotic use in an Italian university hospital.

The aim of this retrospective observational study was to investigate: a) expenditure for antibiotics with respect to the total pharmacy drug budget and to costs of other medical devices; b) the most frequently used antimicrobial classes and molecules; c) the clinical units that most frequently use antimicrobial therapy; d) the preferred route of administration; e) consumption patterns of antibiotics over two periods (January-September 1999 and January-September 2000). The consumption of a single antimicrobial agent was expressed as daily defined doses (DDD) per 100 bed days. In 1999 drugs accounted for 56% of the total costs but decreased to 46% in 2000. Antibiotics accounted for 15% of the pharmacy's overall acquisition costs in 1999 and dropped to 13% in 2000. In both 1999 and 2000, penicillins were used most, followed by cephalosporins and aminoglycosides. In 1999, the most frequently used antibiotic was amoxicillin (4.02 DDD per 100 bed days) followed by ceftazidime, ampicillin, ceftriaxone, and co-amoxiclav. In 2000 ceftriaxone was the most commonly used antibiotic (4.35 DDD per 100 bed days) followed by co-amoxiclav, amoxicillin, ceftazidime. The general surgery, medical therapy and infectious diseases units accounted for the majority of penicillin consumption, while cephalosporins were most widely used in general surgery, orthopedics and neurosurgery units. Parenteral administration was the most widely used route in both years.

Myocardial infarction in diabetic rats: role of hyperglycaemia on infarct size and early expression of hypoxia-inducible factor 1.

AIMS/HYPOTHESIS: This study aimed to evaluate the effects of hyperglycaemia on the evolution of myocardial infarction and the expression of the transcriptional factor for angiogenesis hypoxia-inducible factor 1alpha (HIF-1alpha) in the rat. METHODS: We studied the effects of streptozotocin induced diabetes on infarct size and HIF-1 alpha gene expression. These parameters were also evaluated in isolated hearts of non-diabetic rat, in condition of high glucose concentration. RESULTS: In streptozotocin (STZ)-diabetic rats (in vivo study), myocardial infarct size was greater (p<0.01) in hyperglycaemic rats (22 mmol/l) than in normoglycaemic (7 mmol/l) or non-diabetic rats. In euglycaemic conditions, basal expression of HIF-1alpha mRNA was not appreciable, but increased steadily after ischaemia (762+/-86%, p<0.001); this response was blunted in hyperglycaemic STZ-rats (6.8+/-6% of the control, p<0.001) and improved in euglycaemic STZ-rats (58+/-10%). The changes in myocardial Rac1 mRNA expression paralleled those of HIF-1alpha. In isolated hearts from non-diabetic rats (in vitro study), perfusion with high glucose (33 mmol/l) produced an infarct size (58+/-2% of the area at risk) not different from that obtained in hyperglycaemic STZ-rats (57+/-2%). Similar changes in the expression of HIF-1alpha and Rac1, which were prevented by glutathione infusion (0.3 mmol/l) were also observed. CONCLUSION/INTERPRETATION: Both hyperglycaemia and high glucose concentrations increased basal HIF-1alpha and Rac1 expression, suggesting a state of pseudohypoxia. These findings show that myocardial infarct size in the rat is increased in hyperglycaemic conditions and is associated with a reduced expression of the HIF-1alpha gene. These changes are reversed, totally or partially, by normoglycaemia or glutathione suggesting a role for reactive oxygen species generation brought about by hyperglycaemia.

Effects of docosahexaenoic acid on [Ca(2+)](i) increase induced by doxorubicin in ventricular rat cardiomyocytes.

The clinical use of doxorubicin (DXR) is limited by cardiotoxicity partially due to interference with intracellular Ca(2+) homeostasis and involving the activation of the sarcoplasmic reticulum (SR) Ca(2+) release channels. It is known that docosahexaenoic acid (DHA) is able to potentiate the sensitivity of cancer cells to DXR. The aim of our study was to further evaluate the effects of DHA on [Ca(2+)](i) overload induced by DXR in adult rat ventricular cardiomyocytes in order to verify if DHA interferes with DXR-induced cardiotoxicity too. [Ca(2+)](i) was measured by microfluorimetry. Our data demonstrated that 100 microM DXR induced a statistically significant [Ca(2+)](i)-increase in cardiomyocytes perfused with CaCl(2) Krebs solution (from 135.7 +/- 15 nM to 560.2 +/- 49 nM, n = 9, p < 0.01) and with Ca(2+)-free Krebs solution (from 89.3 +/- 15 nM to 551.1 +/- 35 nM, n = 9, p < 0.01). Treatment with 10 microM DHA for 20 min significantly suppressed DXR [Ca(2+)](i)- increase in cells perfused with CaCl(2) Krebs solution (142.3 +/- 12 nM, n = 9, p < 0.01) and in Ca(2+)-free procedures (100.4 +/- 12 nM, n = 9, p < 0.01). Caffeine 10 mM significantly increased [Ca(2+)](i) in cardiomyocytes perfused with CaCl(2) Krebs solution (from 135.7 +/- 15 nM to 979.2 +/- 17.8 nM, n = 9, p < 0.01) and with Ca(2+)-free Krebs solution (from 89.3 +/- 15 nM to 891.1 +/- 30 nM, n = 9, p < 0.01). Treatment with 10 microM DHA for 20 min suppressed caffeine [Ca(2+)](i)-increase in cardiomyocytes perfused with CaCl(2) Krebs solution (174.2 +/- 28 nM, n = 9, p < 0.01) and in Ca(2+)-free procedures (161.9 +/- 34 nM, n = 9, p < 0.01). In conclusion, our results suggest that DHA is able to prevent acute modifications of calcium homeostasis induced by DXR probably interfering with SR Ca(2+) release channels.

Effects of docosahexaenoic acid on calcium pathway in adult rat cardiomyocytes.

In this study we examined the effect of polyunsaturated fatty acids (PUFAs), in particular of docosahexaenoic acid (DHA), on calcium homeostasis in isolated adult rat cardiomyocytes exposed to KCl, ET-1 and anoxia. Free [Ca(2+)](i) in rat cardiomyocytes was 135.7 +/- 0.5 nM. Exposure to 50 mM KCl or 100 nM ET-1 resulted in a rise in free [Ca(2+)](i) in freshly isolated cells (465.4 +/- 15.6 nM and 311.3 +/- 12.6 nM, respectively) and in cultured cells (450.8 +/- 14.8 nM and 323.5 +/- 14.8 nM respectively). An acute treatment (20 minutes) with 10 microM DHA significantly reduced the KCl- and ET-1-induced [Ca(2+)](i) increase (300.9 +/- 18.1 nM and 232.08 +/- 11.8 nM, respectively). This reduction was greater after chronic treatment with DHA (72 h; 257.7 +/- 13.08 nM and 192.18 +/- 9.8 nM, respectively). Rat cardiomyocytes exposed to a 20 minute superfusion with anoxic solution, obtained by replacing O(2) with N(2) in gas mixture, showed a massive increase in cytosolic calcium (1200.2 +/- 50.2 nM). Longer exposure to anoxia induced hypercontraction and later death of rat cardiomyocytes. Preincubation with DHA reduced the anoxic effect on [Ca(2+)](i) (498.4 +/- 7.3 nM in acute and 200.2 +/- 12.2 nM in chronic treatment). In anoxic conditions 50 mM KCl and 100 nM ET-1 produced extreme and unmeasurable increases of [Ca(2+)](i.) Preincubation for 20 minutes with DHA reduced this phenomenon (856.1 +/- 20.3 nM and 782.3 +/- 7.6 nM, respectively). This reduction is more evident after a chronic treatment with DHA (257.7 +/- 10.6 nM and 232.2 +/- 12.5 nM, respectively). We conclude that in rat cardiomyocytes KCl, ET-1 and anoxia interfered with intracellular calcium concentrations by either modifying calcium levels or impairing calcium homeostasis. Acute, and especially chronic, DHA administration markedly reduced the damage induced by calcium overload in those cells.

Gene expression and morphological changes in surgically injured carotids of spontaneously hypertensive rats.

The expression profiles of genes involved in cell proliferation, differentiation and programmed death were investigated in carotids of spontaneously hypertensive rats (SHR) treated with a model of surgical injury that mimics events occurring during arterial grafts, endarterectomy and organ transplantation. The mRNA level of the c-myc, angiotensin II receptor 1 (AT1), Rb/p105, Rb2/p130, Bcl-2 and Bax-alpha genes was assessed by a semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) technique at different times up to 48 h after injury, while the morphological changes were evaluated 30 days after injury. The proliferation marker c-myc increases almost immediately, peaks after 4 h and returns to basal levels after 24 h; the AT1 receptor mRNA reaches its maximal level 48 h after injury. The level of cell cycle exit markers Rb/p105 and Rb2/p130 gradually decreases after injury. The apoptosis marker Bcl-2/Bax-alpha ratio shows a significant reduction only 4 h after injury, resuming the initial value after 24 and 48 h. Morphological analysis reveals that surgical injury in SHR induces adventitial and medial constrictive remodeling changes rather than intima proliferation as in balloon angioplasty. Both molecular and histological data show substantial differences with respect to normotensive rats.

[Drugs interfering with somatostatin receptors]. / I farmaci interferenti con i recettori della somatostatina.

The use of drugs interfering with somatostatin receptors (ssR) is now consolidated practice in diagnostics and therapy, stimulating the development of new and more efficient molecules offering improved pharmacodynamics. Over the years, we have passed from the use of native somatostatin to mini-somatostatin and then octapeptides, above all octreotide. Subsequently, peptides were synthesized with specific affinities for a single receptorial subtype, like compound BIM23268 and compound CH275. More recently, somatostatin analogs were synthesized with a non-peptide structure. Another important aspect in the history of sst analogs is represented by the development of new pharmaceutical formulas for these drugs in order to improve patient compliance by reducing dose frequency.

Interaction between metabotropic and NMDA glutamate receptors in the periaqueductal grey pain modulatory system.

The formalin test was used to investigate the interactive role of periaqueductal grey (PAG) N-methyl-D-aspartate (NMDA) and metabotropic glutamate (mGlu) receptors in the modulation of persistent noxious stimulation in mice. Intra-PAG microinjections of 1 or 3 nmol NMDA, a selective agonist at NMDA-subtype receptors, decreased the nociceptive response (-94+/-5% with 3 nmol) during the latter phase of the test. This effect was antagonized by MK-801, a selective antagonist at NMDA receptors. No change in the early nociceptive phase was observed after NMDA injection. Pretreatment either with 2-methyl-6-phenylethynylpyridine (MPEP, 25 nmol/mouse), a selective antagonist at mGlu5 receptors, or with (2S)-alpha-ethylglutamic acid [(2S)-alpha-EGlu, 30 nmol/mouse], a selective antagonist at group-II mGluRs, prevented the NMDA-induced antinociceptive effect during the late hyperalgesic phase. Pretreatment with (R,S)-alpha-methylserine-O-phosphate [(R,S)-alpha-MSOP, 70 nmol/mouse], a selective antagonist at group-III mGlu receptors, had no effect on the NMDA-induced antinociception. None of the antagonists changed the formalin-induced nociceptive behaviour per se with the dosages used in combination with NMDA. MPEP at 50 nmol/mouse, however, potentiated the early nociceptive phase whilst 100 nmol/mouse attenuated the late phase. Similarly, at the higher dose of 140 nmol/mouse, (R,S)-alpha-MSOP decreased the late hyperalgesic phase. These results provide additional evidence that NMDA and mGlu receptors participate in modulating the hyperalgesia induced by peripheral noxious stimulation. In particular, mGlu receptors may modulate the NMDA receptors in the PAG since their physiological stimulation seems to be required for the NMDA-induced effect. This suggests that, together with ionotropic glutamate receptors, mGlu receptors also play a role in modulating a type of spinal cord neuroplasticity (i.e. wind-up) that has been proposed to mediate hyperalgesia.