Otilonium Bromide: A Drug with a Complex Mechanism of Action.

Otilonium bromide (OB) is a drug with spasmolytic activity belonging to quaternary ammonium derivatives and extensively used to treat patients affected by the Irritable Bowel Syndrome (IBS). Thanks to its peculiar pharmacokinetic, OB concentrates in the large bowel wall and acts locally. From the pharmacodynamics point of view, OB is able to inhibit i) the main patterns of human colonic motility in vitro; ii) the contractility caused by excitatory motor neurons stimulation (pre-synaptic action) and iii) the contractility caused by the direct action of excitatory neurotransmitters (post-synaptic action). Interestingly, these effects derive from a complex interaction between the drug and several cellular targets. The main action consists in the blockade of Ca2+ entry through L-type Ca2+ channels and interference with intracytoplasmatic Ca2+ mobilization necessary for SMC contraction, thus preventing excessive bowel contractions and abdominal cramps. Further, OB blocks the T-type Ca2+ channels and interferes with the muscarinic responses; it interacts, directly or indirectly, with the tachykinin receptors on SMC and on primary afferent neurons whose combined effects may result in the reduction of motility and abdominal pain. In summary, a revision of this complex picture of OB activity could help to better address its therapeutic use.

Experimental Models of Irritable Bowel Syndrome and the Role of the Enteric Neurotransmission.

Irritable bowel syndrome (IBS) is one of the most common gastrointestinal diseases in humans. It is characterized by visceral pain and/or discomfort, hypersensitivity and abnormal motor responses along with change in gut habits. Although the etio-pathogenesis of IBS is only partially understood, a main role has been attributed to psychosocial stress of different origin. Animal models such as neonatal maternal separation, water avoidance stress and wrap restraint stress have been developed as psychosocial stressors in the attempt to reproduce the IBS symptomatology and identify the cellular mechanisms responsible for the disease. The study of these models has led to the production of drugs potentially useful for IBS treatment. This review intends to give an overview on the results obtained with the animal models; to emphasize the role of the enteric nervous system in IBS appearance and evolution and as a possible target of drug therapies.

Repeated otilonium bromide administration prevents neurotransmitter changes in colon of rats underwent to wrap restraint stress.

Otilonium bromide (OB) is a spasmolytic drug successfully used for the treatment of irritable bowel syndrome (IBS). Its efficacy has been attributed to the block of L- and T-type Ca2+ channels and muscarinic and tachykinin receptors in the smooth muscle. Furthermore, in healthy rats, repeated OB administration modified neurotransmitter expression and function suggesting other mechanisms of action. On this basis, we investigated whether repeated OB treatment prevented the functional and neurochemical changes observed in the colon of rats underwent to wrap restrain stress (WRS) a psychosocial stressor considered suitable to reproduce the main IBS signs and symptoms. In control, WRS and OB/WRS rats functional parameters were measured in vivo and morphological investigations were done ex vivo in the colon. The results showed that OB counteracts most of the neurotransmitters changes caused by WRS. In particular, the drug prevents the decrease in SP-, NK1r-, nNOS-, VIP-, and S100ß-immunoreactivity (IR) and the increase in CGRP-, and CRF1r-IR. On the contrary, OB does not affect the increase in CRF2r-IR neurons observed in WRS rats and does not interfere with the mild mucosal inflammation due to WRS. Finally, OB per se increases the Mr2 expression in the muscle wall and decreases the number of the myenteric ChAT-IR neurons. Functional findings show a significantly reduction in the number of spontaneous abdominal contraction in OB treated rats. The ability of OB to block L-type Ca2+ channels, also expressed by enteric neurons, might represent a possible mechanism through which OB exerts its actions.

Zofenopril Protects Against Myocardial Ischemia-Reperfusion Injury by Increasing Nitric Oxide and Hydrogen Sulfide Bioavailability.

BACKGROUND: Zofenopril, a sulfhydrylated angiotensin-converting enzyme inhibitor (ACEI), reduces mortality and morbidity in infarcted patients to a greater extent than do other ACEIs. Zofenopril is a unique ACEI that has been shown to increase hydrogen sulfide (H2S) bioavailability and nitric oxide (NO) levels via bradykinin-dependent signaling. Both H2S and NO exert cytoprotective and antioxidant effects. We examined zofenopril effects on H2S and NO bioavailability and cardiac damage in murine and swine models of myocardial ischemia/reperfusion (I/R) injury. METHODS AND RESULTS: Zofenopril (10 mg/kg PO) was administered for 1, 8, and 24 hours to establish optimal dosing in mice. Myocardial and plasma H2S and NO levels were measured along with the levels of H2S and NO enzymes (cystathionine ß-synthase, cystathionine γ-lyase, 3-mercaptopyruvate sulfur transferase, and endothelial nitric oxide synthase). Mice received 8 hours of zofenopril or vehicle pretreatment followed by 45 minutes of ischemia and 24 hours of reperfusion. Pigs received placebo or zofenopril (30 mg/daily orally) 7 days before 75 minutes of ischemia and 48 hours of reperfusion. Zofenopril significantly augmented both plasma and myocardial H2S and NO levels in mice and plasma H2S (sulfane sulfur) in pigs. Cystathionine ß-synthase, cystathionine γ-lyase, 3-mercaptopyruvate sulfur transferase, and total endothelial nitric oxide synthase levels were unaltered, while phospho-endothelial nitric oxide synthase(1177) was significantly increased in mice. Pretreatment with zofenopril significantly reduced myocardial infarct size and cardiac troponin I levels after I/R injury in both mice and swine. Zofenopril also significantly preserved ischemic zone endocardial blood flow at reperfusion in pigs after I/R. CONCLUSIONS: Zofenopril-mediated cardioprotection during I/R is associated with an increase in H2S and NO signaling.

Novel therapeutics in the field of capsaicin and pain.

Capsaicin, a pharmacologically active agent found in chili peppers, causes burning and itching sensation due to binding at the transient receptor potential vanilloid-1 (TRPV-1) receptor, a polymodal receptor critical to the sensing of a variety of stimuli (e.g., noxious heat, bidirectional pH), and subsequent activation of polymodal C and A-δ nociceptive fibers. Acutely, TRPV-1 activation with peripheral capsaicin produces pronociceptive effects, which extends to the development of hyperalgesia and allodynia. However, capsaicin has been reported to display antinociceptive properties as well, largely through TRPV-1-dependent mechanisms. Local application of high concentration of capsaicin is used for neuropathic pain and repeated stimulation of TRPV-1 induced an improvement of epigastric pain in irritable bowel syndrome and dyspepsia patients by desensitization of nociceptive pathways. New TRPV-1 agonists are currently under preclinical study and TRPV-1 antagonists are in early clinical development as analgesics. The TRPV-1 pathway might be a novel target for therapeutics in pain sensitivity.

Inner and outer portions of colonic circular muscle: ultrastructural and immunohistochemical changes in rat chronically treated with otilonium bromide.

Rat colonic circular muscle, main target of otilonium bromide (OB) spasmolytic activity, is subdivided in an inner and outer portion. Since the inner one is particularly rich in organelles involved in calcium availability (caveolae, smooth endoplasmic reticulum, mitochondria), the expression of specific markers (Caveolin-1, eNOS, calreticulin, calsequestrin) in comparison with the outer portion was investigated. The possible changes of these organelles and related markers, and of muscarinic receptors (Mr2) were then studied after OB chronic exposition. Rats were treated with 2-20 mg/kg/OB for 10 or 30 days. Proximal colon was processed by electron microscopy, immunohistochemistry, and western blot. In colon strips the stimulated contractility response to muscarinic agonist was investigated. The inner portion showed a higher expression of Caveolin-1 and Mr2, but not of eNOS, calreticulin and calsequestrin, compared to the outer portion. Chronic OB treatment caused similar ultrastructural and immunohistochemical changes in both portions. Organelles and some related markers were increased at 10 days; Mr2 expression and muscle contractility induced by methacholine was increased at 30 days. The present findings: 1) provide new information on the immunohistochemical properties of the inner portion of the circular layer that are in favour of a role it might play in colonic motility distinct from that of the outer portion; 2) demonstrate that chronically administered OB interferes with cell structures and molecules responsible for calcium handling and storage, and modifies cholinergic transmission. In conclusion, chronic OB administration in the colonic circular muscle layer directly interacts with the organelles and molecules calcium-related and with the Mr2.

Capsaicin receptor as target of calcitonin gene-related peptide in the gut.

Calcitonin gene-related peptide (CGRP), a 37 aminoacid-residue peptide, is a marker of afferent fibers in the upper gastrointestinal tract, being almost completely depleted following treatment with the selective neurotoxin capsaicin that targets these fibers via transient receptor potential vanilloid type-1 (TRPV-1). It is widely distributed in the peripheral nervous system of mammals where it is present as alpha isoform, while intrinsic neurons of the enteric nervous systems express predominantly CGRP-beta. Many gastrointestinal functions involve CGRP-containing afferent fibers of the enteric nervous system such as defense against irritants, intestinal nociception, modulation of gastrointestinal motility and secretion, and healing of gastric ulcers. The main effects on stomach homeostasis rely on local vasodilator actions during increased acid-back diffusion. In humans, release of CGRP through the activation of TRPV-1 has been shown to protect from gastric damage induced by several stimuli and to be involved in gastritis. In both dyspepsia and irritable bowel syndrome the repeated stimulation of TRPV-1 induced an improvement in epigastric pain of these patients. The TRPV-1/CGRP pathway might be a novel target for therapeutics in gastric mucosal injury and visceral sensitivity.

Stimulation of platelet nitric oxide production by nebivolol prevents thrombosis.

OBJECTIVE: dl-Nebivolol, a selective ß1-adrenergic receptor antagonist, besides its hypotensive activity exerts vasodilatory and platelet inhibitory effects in vitro by a mechanism involving nitric oxide (NO). Our aim was to evaluate whether nebivolol exerts in vivo antithrombotic effects, to unravel the mechanism of this action and to clarify the relative roles of its 2 enantiomers: d- and l-nebivolol. METHODS AND RESULTS: In wild-type mice, dl-nebivolol, l-nebivolol, and d-nebivolol, but not bisoprolol, reduced mortality consequent to platelet pulmonary thromboembolism induced by the intravenous injection of collagen plus epinephrine (-44%, -45%, -29%, respectively; P<0.05), whereas in eNOS(-/-) mice only dl-nebivolol and d-nebivolol were effective. dl-Nebivolol, l- and d-nebivolol reduced photochemical damage-induced femoral artery thrombosis in wild-type mice, whereas in eNOS(-/-) mice only dl-nebivolol and d-nebivolol were active. Moreover, dl-nebivolol and l-nebivolol increased plasma, urinary-, and platelet-derived nitrites and nitrates (NOx), NO degradation products, in wild-type but not in eNOS(-/-) mice. In vivo platelet activation, assessed by platelet P-selectin expression, was reduced by dl-nebivolol and l- and d-nebivolol in wild-type mice but only by dl-nebivolol and d-nebivolol in eNOS(-/-) mice. In bone marrow-transplanted, chimeric mice with only blood cells, and not the endothelium, producing NO dl-nebivolol and l-nebivolol maintained their antithrombotic activity, whereas they lose it in chimeras with only endothelium, and not blood cells, producing NO. In vitro, with isolated platelets, dl-nebivolol and l-nebivolol, but not d-nebivolol and bisoprolol, increased platelet cGMP and NOx formation. Treatment with dl-nebivolol and l-nebivolol increased phophorylated eNOS in platelets. CONCLUSIONS: Our data show that dl-nebivolol exerts an antithrombotic activity by stimulating the formation of NO by platelets, and that this effect is generated by its l-enantiomer, whereas the d-enantiomer exerts a weak antiplatelet effect because of ß-adrenergic receptor-independent stimulation of adenyly cyclase. These results confirm that platelet-derived NO plays a role in thrombosis prevention and it may represent a target of pharmacological intervention.

Hydrogen sulfide accounts for the peripheral vascular effects of zofenopril independently of ACE inhibition.

AIMS: Therapeutic use of sulfhydrylated inhibitor S-zofenopril has raised different hypotheses regarding the role played by its thiol group in the beneficial clinical effects exerted compared with other angiotensin-converting enzyme (ACE) inhibitors. Here, we investigated hydrogen sulfide (H2S) pathway as accountable for extra-beneficial effects in vascular function. METHODS AND RESULTS: Spontaneously hypertensive rat (SHRs) and control Wistar Kyoto (WKY) rats were treated with either S-zofenopril or enalapril in vivo. Aorta and carotid were harvested and ex vivo vascular reactivity to acetylcholine (Ach) and L-cysteine (L-cys) assessed. Cystathionine-ß-synthase (CBS), cystathionine-γ-lyase (CSE), and 3-mercaptosulfur-transferase (3MST) expression, as well as H2S levels, were evaluated in both vascular tissues. The vascular response to Ach in both carotid and aorta was impaired in SHR (~30%, P < 0.001). S-zofenopril, but not enalapril, restored this response, while L-cys-induced relaxation was enhanced. CSE expression in vessels and tissue/plasma H2S levels were restored to WKY values in SHRs receiving S-zofenopril. In contrast, CBS and 3MST expression were not modified by treatments. S-zofenoprilat, an active metabolite of S-zofenopril, releases H2S in a 'cell-free' assay and it directly relaxed vessels in vitro in a concentration-dependent manner (P < 0.001). In vivo administration of R-zofenoprilat diasteroisomer, which does not inhibit ACE, did not modify blood pressure; nonetheless, it retained the beneficial effect on SHR vascular function as well as restored plasma/tissue H2S levels. CONCLUSION: Our findings establish that S-zofenopril improves vascular function by potentiating the H2S pathway in a model of spontaneous hypertension. This novel mechanism, unrelated to ACE inhibition and based on H2S release, could explain the beneficial effects of sulfhydrylated ACE inhibitors reported in the clinical literature.

Angiotensin-converting-enzyme inhibition counteracts angiotensin II-mediated endothelial cell dysfunction by modulating the p38/SirT1 axis.

OBJECTIVE: Oxidative stress has been linked to endothelial dysfunction and angiotensin II stimulates the reactive oxygen species production contributing to several cardiovascular diseases. We have studied the chain of events induced by angiotensin-converting-enzyme (ACE) activation in vascular umbilical vein endothelial cells (HUVECs) by using an ACE inhibitor such as zofenoprilat. METHODS: We used specific assay to measure the superoxide anion production, tetrazolium bromide (MTT) assay for cell viability, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay for cell apoptosis, and western blot for protein analysis in the study. RESULTS: Zofenoprilat counteracts the superoxide anion production and cell apoptosis induced by angiotensin I treatment by blocking the extrinsic caspase cascade, NF-kB and p38 activation. p38 inhibitor SB203580 reverted the angiotensin II oxidant effects while the p38 constitutively activation, by MKK6 transfection, abrogated the zofenoprilat effects. Characterizing the zofenoprilat downstream effector we found that zofenoprilat reverted the SirT-1 downregulation induced by angiotensin II. p38 activation by angiotensin II was strictly correlated with SirT1 protein downregulation; SB203580 significantly prevented SirT1 downregulation induced by angiotensin II while the p38 constitutive activation abolished SIRT1 protein basal levels. p38 directly bound SirT1 sequestering it in the cytoplasm. SirT1 inhibition by sirtinol annulled zofenoprilat action while SirT1 overexpression reverted the cytotoxic effects of angiotensin II. Finally, zofenoprilat negatively controlled angiotensin I receptor protein expression through SirT1. CONCLUSION: The p38-SirT1 axis is found markedly relevant in modulating the cardiovascular benefit deriving from ACE-inhibitors and might represent a novel target for innovative drugs in cardiovascular prevention.

Beneficial effects of nebivolol and hydrochlorothiazide combination in spontaneously hypertensive rats.

OBJECTIVE: This study examined the combined effect of nebivolol (NEB) and hydrochlorothiazide (HCTZ) on cardiovascular function in spontaneously hypertensive rats (SHR). METHODS: SHR normotensive male rats were randomly assigned to five groups (n = 8 per group): (i) SHR control group; (ii) NEB 2 mg/kg per day group; (iii) HCTZ 10 mg/kg per day group; (iv) NEB 2 mg/kg per day + HCTZ 10 mg/kg per day group; (v) Eight age-matched Wistar-Kyoto normotensive male rats served as the control group. All groups were treated orally for 8 weeks. RESULTS: The combination of NEB + HCTZ synergistically reduced systolic blood pressure and heart rate compared with either monotherapy. HCTZ increased water intake, which is a sign of diuresis. NEB reduced plasma angiotensin II concentration, which was increased in SHR and after HCTZ treatment. NEB + HCTZ increased plasma nitric oxide (NO) concentration and NO synthase activity, which were both reduced in SHR. NEB + HCTZ normalized femoral arterial vasorelaxation induced by acetylcholine, which was impaired in SHR. CONCLUSIONS: The combination of NEB + HCTZ provided a number of beneficial and additive effects due to the synergistic characteristics of both drugs, in an experimental rat model of hypertension.

Neurokinin receptors in the gastrointestinal muscle wall: cell distribution and possible roles.

The neurokinin receptors are G-protein-linked receptors; three distinct molecules, called neurokinin-1, neurokinin-2, and neurokinin-3 receptors, have been identified. Their physiological ligands are the tachykinins, which, in the mammalian gut, correspond to substance P, neurokinin A, and neurokinin B. In this apparatus, the main source of tachykinins is represented by intrinsic neurons located either in the myenteric plexus and projecting mainly to the muscle coat, or in the submucous plexus and projecting to the mucosa and submucosal blood vessels. The availability of specific antibodies has allowed identifying the sites of distribution of the neurokinin receptors in the gut, and important differences have been found among cell types and animal species. The complexity of the receptor distribution, either intraspecies or interspecies, is in agreement with the variegated picture coming out from physiological and pharmacological experiments. Interestingly, most of the knowledge on the tachykinin systems has been obtained from pathological conditions. Here, we tried to collect the main information available on the cellular distribution of the neurokinin receptors in the gut wall in the attempt to correlate their cell location with the several roles the tachykinins seem to play in the gastrointestinal apparatus.

Benefits from long-term treatment in irritable bowel syndrome.

It is known that irritable bowel syndrome (IBS) is a chronic disease of cyclic nature characterized by recurrent symptoms. IBS patients should receive, as initial therapeutic approach a short course of treatment which, if effective, has the additional value of confirming the diagnosis. Long-term treatment should be reserved to diagnosed IBS patients with recurrent symptoms. Clinical trials with stabilized therapies and new active treatments showed an improvement of the symptoms over placebo that is often time-dependent but with high relapse rates (around 40%-50% when stopping treatment). Relapse is not always immediate after stopping treatment and the recent data from OBIS trial with otilonium bromide or with psychotherapy, showed that due to different chemico-physical characteristics of the drugs or the psychosomatic impact to the disease not all treatment gave the same relapsing rate if compared to placebo. Results of IBS clinical trials with different therapies tailored to the patient needs indicate that a cyclic treatment therapy is advisable to counteract the nature of the disease.

Combined antihypertensive and cardioprotective effects of nebivolol and hydrochlorothiazide in spontaneous hypertensive rats.

The antihypertensive and cardioprotective effects of the combination of nebivolol (NEB) and hydrochlorothiazide (HCTZ) in spontaneously hypertensive rats (SHR) were investigated. SHR and age-matched Wistar-Kyoto normotensive rats were randomly assigned to one of six groups: SHR treated with NEB (1 mg/kg/day, intragastric); SHR treated with HCTZ (5 mg/kg/day, intragastric); SHR treated with NEB plus HCTZ (1 + 2.5 mg/kg/day); SHR treated with NEB plus HCTZ (1 + 5 mg/kg/day), along with a SHR and a WKY control group. The effects of NEB and HCTZ on clinical chemistry parameters and on cardiac function and structure were evaluated. NEB and HCTZ in combination had synergistic antihypertensive effects and significantly reduced heart rate and blood pressure compared with monotherapy with either agent. These effects were independent of water intake, urine output and electrolyte excretion. NEB plus HCTZ was associated with reduced oxidative stress in terms of glutathione availability, lower angiotensin I levels as index of plasma renin activity and reduced clearance of urinary sodium compared with HCTZ alone. Cardiac morphometric data and antioxidant parameters indicate that NEB may influence cardiac structure by reducing hypertrophy and by enhancing the availability of endothelial nitric oxide - a unique characteristic of NEB. The authors suggest that a combination of NEB and HCTZ for the treatment of hypertension may be useful for the synergistic characteristics of both drugs.

Effects of zofenopril and ramipril on cough reflex responses in anesthetized and awake rabbits.

Cough is the most common symptom reported by patients in a primary care setting and is one of the most frequent secondary effects recorded during treatment with angiotensin-converting enzyme (ACE) inhibitors. The aim of the current study was to analyze potential differences in cough induction between 2 structurally different ACE inhibitors, namely zofenopril, which has a sulphydryl moiety, and ramipril, which has a carboxyl moiety. The cough reflex was induced by chemical (citric acid) and/or mechanical stimulation of the tracheobronchial tree in awake and anesthetized rabbits. Intravenous injection of the active compounds of the 2 ACE inhibitors, zofenoprilat (288 nmol/kg) and ramiprilat (129 nmol/kg), caused similar hypotensive effects in anesthetized rabbits. None of the studied cough-related variables changed in response to ACE inhibitor administration, with the exception of the number of coughs. Ramiprilat, but not zofenoprilat, increased the cough response induced by both mechanical and chemical stimulation (1 mol/L citric acid aerosol) of the tracheobronchial tree. In awake animals, zofenoprilat- or vehicle-treated rabbits did not show any significant changes in the number of coughs induced by 1 mol/L citric acid aerosol compared to their respective basal values (from 15.2 ± 2.3 to 13.1 ± 1.3 and from 16.1 ± 4.9 to 15.8 ± 4.3, respectively). Conversely, ramiprilat resulted in a significant increase in the number of coughs (from 21.1 ± 2.6 to 34.9 ± 3.5; P < .01). These findings confirm that there are differences in the cough potentiation effect induced by different ACE inhibitors. The low rate of cough seen with zofenoprilat may be related to its ability to induce a lower accumulation of bradykinin and prostaglandins at the lung level.

T-type Ca(2+) channel modulation by otilonium bromide.

Antispasmodics are used clinically to treat a variety of gastrointestinal disorders by inhibition of smooth muscle contraction. The main pathway for smooth muscle Ca(2+) entry is through L-type channels; however, there is increasing evidence that T-type Ca(2+) channels also play a role in regulating contractility. Otilonium bromide, an antispasmodic, has previously been shown to inhibit L-type Ca(2+) channels and colonic contractile activity. The objective of this study was to determine whether otilonium bromide also inhibits T-type Ca(2+) channels. Whole cell currents were recorded by patch-clamp technique from HEK293 cells transfected with cDNAs encoding the T-type Ca(2+) channels, Ca(V)3.1 (alpha1G), Ca(V)3.2 (alpha1H), or Ca(V)3.3 (alpha1I) alpha subunits. Extracellular solution was exchanged with otilonium bromide (10(-8) to 10(-5) M). Otilonium bromide reversibly blocked all T-type Ca(2+) channels with a significantly greater affinity for Ca(V)3.3 than Ca(V)3.1 or Ca(V)3.2. Additionally, the drug slowed inactivation in Ca(V)3.1 and Ca(V)3.3. Inhibition of T-type Ca(2+) channels may contribute to inhibition of contractility by otilonium bromide. This may represent a new mechanism of action for antispasmodics and may contribute to the observed increased clinical effectiveness of antispasmodics compared with selective L-type Ca(2+) channel blockers.

Skeletal muscle proteins oxidation in chronic right heart failure in rats: can different beta-blockers prevent it to the same degree?

BACKGROUND: Skeletal muscle atrophy and decreased expression of slow fibers contribute to exercise capacity limitation in Chronic Heart Failure (CHF). Pro-inflammatory cytokines and free radicals worsen muscle damage. In CHF sarcomeric proteins are oxidized with reduction of muscle twitch efficiency, and VO(2)-max. Beta-blockers with anti-oxidative capacity such as carvedilol have been shown to prevent contractile protein oxidation in CHF rats. Recently a new class of beta-blockers with NO donor activity has been introduced and approved for the treatment of CHF. Since a clinical clear superiority of a beta-blocker has never been shown, we compared nebivolol, that possesses NO donor activity, with bisoprolol, looking at possible differences in skeletal muscle that may have an impact on muscle function and exercise capacity in humans. We therefore studied skeletal muscle apoptosis and wastage, sarcomeric protein composition and oxidation, and muscle efficiency. METHODS AND RESULTS: In the monocrotaline rat model of CHF we compared nebivolol a beta-blocker with vasodilative properties mediated by NO production, with bisoprolol. Nebivolol prevented protein oxidation, while bisoprolol did it only partially, as demonstrated by the oxyblot analysis (Oxy/RP values) (0.90+/-0.14 Controls.; 1.7+/-0.14 CHF; 1.1+/-0.05 bisoprolol; 0.82+/-0.17 nebivolol low; 0.62+/-0.10 nebivolol high). Only nebivolol improved twitch force production and relaxation. Nebivolol prevented fibers shift towards fast isoforms, atrophy, decreased apoptosis and sphingosine levels. CONCLUSIONS: Nebivolol seems better than bisoprolol in CHF by decreasing apoptosis and cytokines induced muscle wastage, preventing fibers shift and protein oxidation. Nebivolol by stimulating NO generation may have prevented protein oxidation. It could be speculated that ROS release, pro-inflammatory cytokines production and NF-kappa-B activation may play a key role. These positive changes could produce a favorable impact on exercise capacity in man.

Tachykinin receptor antagonists in clinical trials.

Tachykinins (TKs) are small peptides widely distributed in the central and peripheral nervous systems where they act as neurotransmitters. Potent and selective TKs antagonists have been developed in the last 20 years and many efforts have been made to prove their efficacy in the treatment of various diseases. Herein the most prominent results in the clinical development are reported and discussed. For aprepitant, the only compound of this class to have been launched to date, results of clinical studies and postmarketing cost-effectiveness data for the treatment of chemotherapy-induced emesis are discussed. The field is still well active, as currently proof-of-concept studies for indications initially missed (i.e., depression) are ongoing and new targets are under investigation.

ACE inhibition and protection from doxorubicin-induced cardiotoxicity in the rat.

The angiotensin converting enzyme inhibitor zofenopril has been shown to possess cardioprotective effects toward myocardial damage induced by chronic doxorubicin treatment in the rat. In the present study we have investigated the relationship between cardioprotection exerted by 2 angiotensin converting enzyme inhibitors (zofenopril and lisinopril) and degree of inhibition of cardiac versus serum angiotensin converting enzyme. Both zofenopril and lisinopril produced a dose-dependent inhibition of serum and cardiac angiotensin converting enzyme in rats (0.1, 1 or 10 mg/kg/day in the diet for 1 week). However, zofenopril at 0.1 mg/kg/day showed a significantly (P < 0.05) greater inhibition of angiotensin converting enzyme in the myocardium than in the serum (delta about 20%). Using dose levels (0.1 mg/kg/day and 10 mg/kg/day) which inhibits partially (about 50%) or almost totally (about 80%) serum angiotensin converting enzyme, we evaluated the effects of zofenopril and lisinopril in preventing cardiac alterations (QalphaT prolongation) induced by chronic treatment with doxorubicin (1.5 mg/kg q7dx5 i.v.). Zofenopril, at a dose level (0.1 mg/kg/ day) that did not affect haemodynamics and only partially inhibits serum angiotensin converting enzyme activity, almost totally prevent the QalphaT lengthening induced by doxorubicin, whereas lisinopril was ineffective at this dose level. At the higher dose level (10 mg/kg/day), both angiotensin converting enzyme inhibitors totally prevented the electrocardiographic alteration induced by chronic doxorubicin administration. Cardioprotection exerted by zofenopril at a dose level that partially inhibits serum angiotensin converting enzyme without affecting haemodynamics, suggests that inhibition of cardiac angiotensin converting enzyme and additional cardioprotective mechanism(s) may have a role in its ability to prevent myocardial damages in the rat subjected to chronic anthracycline treatment.

Vernon Lee in the Vatican: the uneasy alliance of aestheticism and archaeology.

From the 1800s onward, aesthetic critics attempted to free the study of ancient Greek art from the frameworks of institutional education and professionalized criticism. In this process, aestheticism entered an uneasy alliance with archaeology, a discipline that was likewise challenging traditional modes of classical learning practiced in public schools and the old universities. In "The Child in the Vatican" (1881), Vernon Lee -- writing under the influence of Pater and from a position of cosmopolitan female amateurism -- examines the uses of archaeological science in the study of classical art. Her analysis of the sculptures of the Niobe Group at once relies on the archaeological method and asks readers to doubt scientific approaches to art that dim the sublime power of the art object.