A History of the Pharmacological Treatment of Bipolar Disorder.

In this paper, the authors review the history of the pharmacological treatment of bipolar disorder, from the first nonspecific sedative agents introduced in the 19th and early 20th century, such as solanaceae alkaloids, bromides and barbiturates, to John Cade's experiments with lithium and the beginning of the so-called "Psychopharmacological Revolution" in the 1950s. We also describe the clinical studies and development processes, enabling the therapeutic introduction of pharmacological agents currently available for the treatment of bipolar disorder in its different phases and manifestations. Those drugs include lithium salts, valproic acid, carbamazepine, new antiepileptic drugs, basically lamotrigine and atypical antipsychotic agents (olanzapine, risperidone, quetiapine, ziprasidone, aripiprazole, asenapine, cariprazine and lurasidone). Finally, the socio-sanitary implications derived from the clinical introduction of these drugs are also discussed.

Role of endothelial nitric oxide in pulmonary and systemic arteries during hypoxia.

UNLABELLED: Our aim was to investigate the role played by endothelial nitric oxide (NO) during acute vascular response to hypoxia, as a modulator of both vascular tone (through guanylate cyclase (sGC) activation) and mitochondrial O2 consumption (through competitive inhibition of cytochrome-c-oxydase (CcO)). Organ bath experiments were performed and O2 consumption (Clark electrode) was determined in isolated aorta, mesenteric and pulmonary arteries of rats and eNOS-knockout mice. All pre-contracted vessels exhibited a triphasic hypoxic response consisting of an initial transient contraction (not observed in vessels from eNOS-knockout mice) followed by relaxation and subsequent sustained contraction. Removal of the endothelium, inhibition of eNOS (by L-NNA) and inhibition of sGC (by ODQ) abolished the initial contraction without altering the other two phases. The initial hypoxic contraction was observed in the presence of L-NNA+NO-donors. L-NNA and ODQ increases O2 consumption in hypoxic vessels and increases the arterial tone in normoxia but not in hypoxia. When L-NNA+mitochondrial inhibitors (cyanide, rotenone or myxothiazol) were added, the increase in tone was similar in normoxic and hypoxic vessels, which suggests that inhibition of the binding of NO to reduced CcO restored the action of NO on sGC. CONCLUSION: A complex equilibrium is established between NO, sGC and CcO in vessels in function of the concentration of O2: as O2 falls, NO inhibition of mitochondrial O2 consumption increases and activation of sGC decreases, thus promoting a rapid increase in tone in both pulmonary and systemic vessels, which is followed by the triggering of NO-independent vasodilator/vasoconstrictor mechanisms.

Evidence for the involvement of TRPV2 channels in the modulation of vascular tone in the mouse aorta.

AIMS: Transient receptor potential vanilloid 2 (TRPV2) channels are expressed in both smooth muscle and endothelial cells and participate in vascular mechanotransduction and sensing of high temperatures and lipids. Nevertheless, the impact of TRPV2 channel activation by agonists on the coordinated and cell-type specific modulation of vasoreactivity is unknown. MAIN METHODS: Aorta from 2- to 4-months-old male Oncins France 1 mice was dissected and mounted in tissue baths for isometric tension measurements. TRPV2 channel expression was assessed by immunofluorescence and western blot in mice aortas and in cultured A7r5 rat aortic smooth muscle cells. KEY FINDINGS: TRPV2 channels were expressed in all three mouse aorta layers. Activation of TRPV2 channels with probenecid evoked endothelium-dependent relaxations through a mechanism that involved activation of smooth muscle Kir and Kv channels. In addition, TRPV2 channel inhibition with tranilast increased endothelium-independent relaxations to probenecid and this effect was abrogated by the KATP channel blocker glibenclamide, revealing that smooth muscle TRPV2 channels induce negative feedback on probenecid relaxations mediated via KATP channel inhibition. Exposure to the NO donor sodium nitroprusside increased TRPV2 channel translocation to the plasma membrane in cultured smooth muscle cells and enhanced negative feedback on probenecid relaxations. SIGNIFICANCE: In conclusion, we present the first evidence that TRPV2 channels may modulate vascular tone through a balance of opposed inputs from the endothelium and the smooth muscle leading to net vasodilation. The fact that TRPV2 channel-induced activity can be amplified by NO emphasizes the pathophysiological relevance of these findings.

Different expression of adrenoceptors and GRKs in the human myocardium depends on heart failure etiology and correlates to clinical variables.

Downregulation of ß(1)- adrenergic receptors (ß(1)-ARs) and increased expression/function of G-protein-coupled receptor kinase 2 (GRK2) have been observed in human heart failure, but changes in expression of other ARs and GRKs have not been established. Another unresolved question is the incidence of these compensatory mechanisms depending on heart failure etiology and treatment. To analyze these questions, we quantified the mRNA/protein expressions of six ARs (α(1A), α(1B), α(1D), ß(1), ß(2), and ß(3)) and three GRKs (GRK2, GRK3, and GRK5) in left (LV) and right ventricle (RV) from four donors, 10 patients with ischemic cardiomyopathy (IC), 14 patients with dilated cardiomyopathy (DC), and 10 patients with nonischemic, nondilated cardiopathies (NINDC). We correlated the changes in the expressions of ARs and GRKs with clinical variables such as left ventricular ejection fraction (LVEF) and left ventricular end-systolic and left ventricular end-diastolic diameter (LVESD and LVEDD, respectively). The main findings were 1) the expression of the α(1A)-AR in the LV positively correlates with LVEF; 2) the expression of GRK3 and GRK5 inversely correlates with LVESD and LVEDD, supporting previous observations about a protective role for both kinases in failing hearts; and 3) ß(1)-AR expression is downregulated in the LV and RV of IC, in the LV of DC, and in the RV of NINDC. This difference, better than an increased expression of GRK2 (not observed in IC), determines the lower LVEF in IC and DC vs. NINDC.

Myocardial G protein receptor-coupled kinase expression correlates with functional parameters and clinical severity in advanced heart failure.

BACKGROUND: In heart failure (HF), sympathetic hyperactivation induces deleterious effects in myocardial ß-adrenergic signaling, with receptor down-regulation and desensitization mediated by G protein receptor-coupled kinases (GRKs). We hypothesised that changes in GRK isoforms may be associated with clinical status in advanced HF, using the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) scale. METHODS: We included 31 patients with advanced HF undergoing transplantation. According to INTERMACS profiles, mRNA and protein levels of GRK isoforms in left ventricular (LV) myocardium were analyzed and compared with nonfailing LV samples. RESULTS: In failing LV myocardium, GRK2 and GRK5 (but not GRK3) protein was up-regulated compared with control samples. Among HF patients, an increase in GRK2 and GRK5 mRNA and protein abundance was observed in ß-agonist-treated patients (vs ß-blockers: P < .05) and in higher-risk INTERMACS status (profiles 2 and 3 vs 4 and 5: P < .05). A significant negative correlation of GRK2 expression with LV stroke volume supported these findings. CONCLUSIONS: Increased GRK2 correlates with clinical severity using the INTERMACS scale and LV stroke volume, supporting it as a potential target in advanced HF. These changes are paralleled by GRK5 expression in the failing myocardium, suggesting a relevant role in human HF.

Role of serendipity in the discovery of classical antidepressant drugs: Applying operational criteria and patterns of discovery.

The role played by serendipity in the origin of modern psychopharmacology has proven to be controversial in scientific literature. In its original meaning (Walpole), serendipity refers to discoveries made through a combination of accidents and sagacity. We have implemented an operational definition of serendipity based on finding something unexpected or unintended, regardless of the systematic process that led to the accidental observation, and we have established four different patterns of serendipitous attributability. In this paper, we have analyzed the role of serendipity in the discovery and development of classical antidepressant drugs, tricyclic antidepressants and monoamine oxidase inhibitors as well as heterocyclic, "atypical" or "second generation" antidepressants. The discovery of the antidepressant properties of imipramine and iproniazid, the prototypes of tricyclic antidepressants and monoamine oxidase inhibitors, respectively, fits the mixed type II pattern; initial serendipitous discoveries (imipramine was an antipsychotic and iproniazid was an anti-tuberculosis agent) led secondarily to non-serendipitous discoveries. But the other components of these two families of drugs were developed specifically as antidepressants, modifying the chemical structure of the series leaders, thereby allowing all of them to be included in the type IV pattern, characterized by the complete absence of serendipity. Among the heterocyclic drugs, mianserin (originally developed as an antihistamine) also falls into the type II pattern.

An Imidazoline 2 Receptor Ligand Relaxes Mouse Aorta via Off-Target Mechanisms Resistant to Aging.

Imidazoline receptors (IR) are classified into three receptor subtypes (I1R, I2R, and I3R) and previous studies showed that regulation of I2R signaling has neuroprotective potential. In order to know if I2R has a role in modulating vascular tone in health and disease, we evaluated the putative vasoactive effects of two recently synthesized I2R ligands, diethyl (1RS,3aSR,6aSR)-5-(3-chloro-4-fluorophenyl)-4,6-dioxo-1-phenyl-1,3a,4,5,6,6a-hexahydropyrrolo[3,4-c]pyrrole -1-phosphonate (B06) and diethyl [(1-(3-chloro-4-fluorobenzyl)-5,5-dimethyl-4-phenyl-4,5-dihydro-1H-imidazol-4-yl]phosphonate] (MCR5). Thoracic aortas from Oncins France 1 (3- to 4-months-old) and C57BL/6 (3- to 4- and 16- to 17-months-old mice) were mounted in tissue baths to measure isometric tension. In young mice of both strains, MCR5 induced greater relaxations than either B06 or the high-affinity I2R selective ligand 2-(2-benzofuranyl)-2-imidazoline (2-BFI), which evoked marginal responses. MCR5 relaxations were independent of I2R, as IR ligands did not significantly affect them, involved activation of smooth muscle KATP channels and inhibition of L-type voltage-gated Ca2+ channels, and were only slightly modulated by endothelium-derived nitric oxide (negatively) and prostacyclin (positively). Notably, despite the presence of endothelial dysfunction in old mice, MCR5 relaxations were preserved. In conclusion, the present study provides evidence against a functional contribution of I2R in the modulation of vascular tone in the mouse aorta. Moreover, the I2R ligand MCR5 is an endothelium-independent vasodilator that acts largely via I2R-independent pathways and is resistant to aging. We propose MCR5 as a candidate drug for the management of vascular disease in the elderly.

Regulation of oxygen distribution in tissues by endothelial nitric oxide.

Nitric oxide (NO) decreases cellular oxygen (O(2)) consumption by competitively inhibiting cytochrome c oxidase. Here, we show that endogenously released endothelial NO, either basal or stimulated, can modulate O(2) consumption both throughout the thickness of conductance vessels and in the microcirculation. Furthermore, we have shown that such modulation regulates O(2) distribution to the surrounding tissues. We have demonstrated these effects by measuring O(2) consumption in blood vessels in a hypoxic chamber and O(2) distribution in the microcirculation using the fluorescent oxygen-probe Ru(phen)(3)(2+). Removal of NO by physical or pharmacological means, or in eNOS(-/-) mice, abolishes this regulatory mechanism. Our results indicate that, in addition to its well-known effect on the regulation of vascular tone, endothelial NO plays a major role in facilitating the distribution of O(2), an action which is crucial for the adaptation of tissues, including the vessel wall itself, to hypoxia. It is possible that changes in the distribution of O(2) throughout the vessel wall may be implicated in the origin of vascular pathologies such as atherosclerosis.

MicroRNAs and Oxidative Stress: An Intriguing Crosstalk to Be Exploited in the Management of Type 2 Diabetes.

Type 2 diabetes is a chronic disease widespread throughout the world, with significant human, social, and economic costs. Its multifactorial etiology leads to persistent hyperglycemia, impaired carbohydrate and fat metabolism, chronic inflammation, and defects in insulin secretion or insulin action, or both. Emerging evidence reveals that oxidative stress has a critical role in the development of type 2 diabetes. Overproduction of reactive oxygen species can promote an imbalance between the production and neutralization of antioxidant defence systems, thus favoring lipid accumulation, cellular stress, and the activation of cytosolic signaling pathways, and inducing ß-cell dysfunction, insulin resistance, and tissue inflammation. Over the last few years, microRNAs (miRNAs) have attracted growing attention as important mediators of diverse aspects of oxidative stress. These small endogenous non-coding RNAs of 19-24 nucleotides act as negative regulators of gene expression, including the modulation of redox signaling pathways. The present review aims to provide an overview of the current knowledge concerning the molecular crosstalk that takes place between oxidative stress and microRNAs in the physiopathology of type 2 diabetes, with a special emphasis on its potential as a therapeutic target.

NT3/TrkC Pathway Modulates the Expression of UCP-1 and Adipocyte Size in Human and Rodent Adipose Tissue.

Neurotrophin-3 (NT3), through activation of its tropomyosin-related kinase receptor C (TrkC), modulates neuronal survival and neural stem cell differentiation. It is widely distributed in peripheral tissues (especially vessels and pancreas) and this ubiquitous pattern suggests a role for NT3, outside the nervous system and related to metabolic functions. The presence of the NT3/TrkC pathway in the adipose tissue (AT) has never been investigated. Present work studies in human and murine adipose tissue (AT) the presence of elements of the NT3/TrkC pathway and its role on lipolysis and adipocyte differentiation. qRT-PCR and immunoblot indicate that NT3 (encoded by NTF3) was present in human retroperitoneal AT and decreases with age. NT3 was also present in rat isolated adipocytes and retroperitoneal, interscapular, perivascular, and perirenal AT. Histological analysis evidences that NT3 was mainly present in vessels irrigating AT close associated to sympathetic fibers. Similar mRNA levels of TrkC (encoded by NTRK3) and ß-adrenoceptors were found in all ATs assayed and in isolated adipocytes. NT3, through TrkC activation, exert a mild effect in lipolysis. Addition of NT3 during the differentiation process of human pre-adipocytes resulted in smaller adipocytes and increased uncoupling protein-1 (UCP-1) without changes in ß-adrenoceptors. Similarly, transgenic mice with reduced expression of NT3 (Ntf3 knock-in lacZ reporter mice) or lacking endothelial NT3 expression (Ntf3flox1/flox2;Tie2-Cre+/0) displayed enlarged white and brown adipocytes and lower UCP-1 expression. Conclusions: NT3, mainly released by blood vessels, activates TrkC and regulates adipocyte differentiation and browning. Disruption of NT3/TrkC signaling conducts to hypertrophied white and brown adipocytes with reduced expression of the thermogenesis marker UCP-1.

Stenosis coexists with compromised α1-adrenergic contractions in the ascending aorta of a mouse model of Williams-Beuren syndrome.

Williams-Beuren syndrome (WBS) is a rare disorder caused by a heterozygous deletion of 26-28 contiguous genes that affects the brain and cardiovascular system. Here, we investigated whether WBS affects aortic structure and function in the complete deletion (CD) mouse model harbouring the most common deletion found in WBS patients. Thoracic aortas from 3-4 months-old male CD mice and wild-type littermates were mounted in wire myographs or were processed for histomorphometrical analysis. Nitric oxide synthase (NOS) isoforms and oxidative stress levels were assessed. Ascending aortas from young adult CD mice showed moderate (50%) luminal stenosis, whereas endothelial function and oxidative stress were comparable to wild-type. CD mice showed greater contractions to KCl. However, α1-adrenergic contractions to phenylephrine, but not with a thromboxane analogue, were compromised. Decreased phenylephrine responses were not affected by selective inducible NOS blockade with 1400 W, but were prevented by the non-selective NOS inhibitor L-NAME and the selective neuronal NOS inhibitor SMTC. Consistently, CD mice showed increased neuronal NOS expression in aortas. Overall, aortic stenosis in CD mice coexists with excessive nNOS-derived NO signaling that compromises ascending aorta α1-adrenergic contractions. We suggest that increased neuronal NOS signaling may act as a physiological 'brake' against the detrimental effects of stenosis.

The impact of alpha1-adrenoceptors up-regulation accompanied by the impairment of beta-adrenergic vasodilatation in hypertension.

In human and animal hypertension models, increased activity of G-protein-coupled receptor kinase (GRK) 2 determines a generalized decrease of beta-adrenergic vasodilatation. We analyzed the possibility of differential changes in the expression and functionality of alpha(1A), alpha(1B), alpha(1D), beta(1), beta(2), and beta(3)-ARs also being involved in the process. We combined the quantification of mRNA levels with immunoblotting and functional studies in aortas of young and adult spontaneously hypertensive rats (SHRs) and their controls (Wistar Kyoto). We found the expression and function of beta(1)-adrenoceptors in young prehypertensive SHRs to be higher, whereas a generalized increase in the expression of the six adrenoceptors and GRK2 was observed in aortas of adult hypertensive SHRs. alpha(1D)- and beta(3)-adrenoceptors, the subtypes that are more resistant to GRK2-mediated internalization and mostly expressed in rat aorta, exhibited an increased functional role in hypertensive animals, showing two hemodynamic consequences: 1) an increased sensitivity to the vasoconstrictor stimulus accompanied by a decreased sensitivity to the vasodilator stimulus (alpha(1D)-ARs are the most sensitive to agonists, and beta(3)-ARs are the least sensitive to agonists); and 2) a slower recovery of the basal tone after adrenergic stimulus removal because of the kinetic characteristic of the alpha(1D) subtype. These functional changes might be involved in the greater sympathetic vasoconstrictor tone observed in hypertension.

Beta-blockers: Historical Perspective and Mechanisms of Action.

Beta-blockers are widely used molecules that are able to antagonize ß-adrenergic receptors (ARs), which belong to the G protein-coupled receptor family and receive their stimulus from endogenous catecholamines. Upon ß-AR stimulation, numerous intracellular cascades are activated, ultimately leading to cardiac contraction or vascular dilation, depending on the relevant subtype and their location. Three subtypes have been described that are differentially expressed in the body (ß1-, ß2- and ß3-ARs), ß1 being the most abundant subtype in the heart. Since their discovery, ß-ARs have become an important target to fight cardiovascular disease. In fact, since their discovery by James Black in the late 1950s, ß-blockers have revolutionized the field of cardiovascular therapies. To date, 3 generations of drugs have been released: nonselective ß-blockers, cardioselective ß-blockers (selective ß1-antagonists), and a third generation of these drugs able to block ß1 together with extra vasodilation activity (also called vasodilating ß-blockers) either by blocking α1- or by activating ß3-AR. More than 50 years after propranolol was introduced to the market due to its ability to reduce heart rate and consequently myocardial oxygen demand in the event of an angina attack, ß-blockers are still widely used in clinics.

ß2-Adrenoceptors and GRK2 as Potential Biomarkers in Patients With Chronic Pulmonary Regurgitation.

Pulmonary regurgitation (PR) is a frequent complication after repair of congenital heart disease. Three different GRK isoforms (GRK2, GRK5, and GRK3) and two ß-adrenoceptors (ß1-AR and ß2-AR) are present in peripheral blood mononuclear cells (PBMC) and their expression changes as a consequence of the hemodynamic and neurohumoral alterations that occur in some cardiovascular diseases. Therefore, they could be useful as biomarkers in PR. A prospective study was conducted to describe the expression (TaqMan Gene Expression Assays) of ß-ARs and GRKs in PBMC isolated (Ficoll® gradient) from patients with severe PR before and after pulmonary valve replacement and establish if this expression correlates to clinical status. 23 patients with severe PR were included and compared with 22 healthy volunteers (controls). PR patients before the PVR had a significantly lower expression of ß2-AR (513.8 ± 261.2 mRNA copies) vs. controls (812.5 ± 497.2 mRNA copies), so as GRK2 expression (503.4 ± 364.9 copies vs. 858.1 ± 380.3 mRNA copies). The expression of ß2-AR and GRK2 significantly decreases in symptomatic and asymptomatic patients, as well as in patients under treatment with beta-blockers and non-treated patients. The expression of ß2-AR and GRK2 in PR patients recovers the normal values after pulmonary valve replacement (754,8 ± 77,1 and 897,8 ± 87,4 copies, respectively). Therefore, changes in the expression of ß2-AR and GRK2 in PBMC of PR patients, could be considered as potential biomarkers to determine clinical decisions.

Uric acid treatment after stroke modulates the Krüppel-like factor 2-VEGF-A axis to protect brain endothelial cell functions: Impact of hypertension.

Uric acid (UA) is a promising protective treatment in ischaemic stroke, but the precise molecular targets underlying its in vivo beneficial actions remain unclear. High concentrations of UA inhibit angiogenesis of cultured endothelial cells via Krüppel-like factor 2 (KLF)-induced downregulation of vascular endothelial growth factor (VEGF), a pro-angiogenic mediator that is able to increase blood-brain barrier (BBB) permeability in acute stroke. Here, we investigated whether UA treatment after ischaemic stroke protects brain endothelial cell functions and modulates the KLF2-VEGF-A axis. Transient intraluminal middle cerebral artery (MCA) occlusion/reperfusion was induced in adult male spontaneously hypertensive (SHR) rats and corresponding normotensive Wistar-Kyoto (WKY) rats. Animals received UA (16 mg/kg) or vehicle (Locke's buffer) i.v. at reperfusion. BBB permeability was evaluated by Evans blue extravasation to the brain and in human cerebral endothelial hCMEC/D3 cells under oxygen-glucose deprivation/re-oxygenation. Circulating VEGF-A levels were measured in rats and acute ischaemic stroke patients from the URICO-ICTUS trial. Angiogenesis progression was assessed in Matrigel-cultured MCA. Worse post-stroke brain damage in SHR than WKY rats was associated with higher hyperaemia at reperfusion, increased Evans blue extravasation, exacerbated MCA angiogenic sprouting, and higher VEGF-A levels. UA treatment reduced infarct volume and Evans blue leakage in both rat strains, improved endothelial cell barrier integrity and KLF2 expression, and lowered VEGF-A levels in SHR rats. Hypertensive stroke patients treated with UA showed lower levels of VEGF-A than patients receiving vehicle. Consistently, UA prevented the enhanced MCA angiogenesis in SHR rats by a mechanism involving KLF2 activation. We conclude that UA treatment after ischaemic stroke upregulates KLF2, reduces VEGF-A signalling, and attenuates brain endothelial cell dysfunctions leading to neuroprotection.

Complex I dysfunction and tolerance to nitroglycerin: an approach based on mitochondrial-targeted antioxidants.

Nitroglycerin (GTN) tolerance was induced in vivo (rats) and in vitro (rat and human vessels). Electrochemical detection revealed that the incubation dose of GTN (5x10(-6) mol/L) did not release NO or modify O(2) consumption when administered acutely. However, development of tolerance produced a decrease in both mitochondrial O(2) consumption and the K(m) for O(2) in animal and human vessels and endothelial cells in a noncompetitive action. GTN tolerance has been associated with impairment of GTN biotransformation through inhibition of aldehyde dehydrogenase (ALDH)-2, and with uncoupling of mitochondrial respiration. Feeding rats with mitochondrial-targeted antioxidants (mitoquinone [MQ]) and in vitro coincubation with MQ (10(-6) mol/L) or glutathione (GSH) ester (10(-4) mol/L) prevented tolerance and the effects of GTN on mitochondrial respiration and ALDH-2 activity. Biotransformation of GTN requires functionally active mitochondria and induces reactive oxygen species production and oxidative stress within this organelle, as it is inhibited by mitochondrial-targeted antioxidants and is absent in HUVECrho(0) cells. Experiments analyzing complex I-dependent respiration demonstrate that its inhibition by GTN is prevented by mitochondrial-targeted antioxidants. Furthermore, in presence of succinate (10x10(-3) mol/L), a complex II electron donor added to bypass complex I-dependent respiration, GTN-treated cells exhibited O(2) consumption rates similar to those of controls, thus suggesting that complex I was affected by GTN. We propose that, following prolonged treatment with GTN in addition to ALDH-2, complex I is a target for mitochondrially generated reactive oxygen species. Our data also suggest a role for mitochondrial-targeted antioxidants as therapeutic tools in the control of the tolerance that accompanies chronic nitrate use.

Dexamethasone Preconditioning in Cardiac Procedures Reduces Decreased Antithrombin Activity and Is Associated to Beneficial Outcomes: Role of Endothelium.

Introduction: Decreased antithrombin (AT) activity in patients scheduled for cardiovascular surgery under cardiopulmonary bypass (CPB) is related to increased postoperative complications and hospitalization time. Indirect evidence suggests that glucocorticoids mitigate this decreased AT activity. To better understand the beneficial effects of AT we have analyzed: (i) the clinical relevance of acute dexamethasone (DX) administration before cardiac surgery on AT activity, (ii) the modulation by DX of AT expression in human endothelial cells (hECs), (iii) the activity of AT on migration and angiogenesis of hECs, or on angiogenesis of rat aorta. Methods: A retrospective cohort study in patients undergoing aortic valve replacement surgery was designed to evaluate the effect of DX administration on AT activity at five separate time points: preoperatively, during CPB, at intensive care unit admission and at 12 and 24 h post-intervention. We have analyzed also clinical differences in postoperative outcomes as safety and the length of stay in hospitalization. Changes in mRNA levels of AT induced by DX were determined by qRT-PCR in human coronary (hCEC), aorta (hAEC) and cardiac microvasculature (hCMEC) endothelial cells. AT activity on migration and angiogenesis were also assayed. Angiogenic growth of rat aortic rings incubated in Matrigel® was determined in presence and absence of AT. Results: The cohort comprised 51 patients in the control group and 29 patients in the group receiving dexamethasone. Preoperative DX supplementation reduced intraoperative decrease of AT activity (67.71 ± 10.49% DX treated vs. 58.12 ± 9.11% untreated, p < 0.001) that could be related to a decrease in the hospitalization time (7.59 ± 4.08 days DX treated vs. 13.59 ± 16.00 days untreated, p = 0.014). Treatment of hECs with 500 nM DX slightly increased AT expression. Incubation with 0.5 and 1 IU/mL of AT increased migration and angiogenesis in hCAECs and hAECs, but not in hCMECs. The same concentrations of AT potentiated angiogenic sprouting of new vessels from rat aorta. Conclusion: Preoperative DX supplementation could be an interesting procedure to avoid excessive decrease in AT levels during cardiac surgery. Positive outcomes associated with maintaining adequate AT levels could be related to its potential beneficial effect on endothelial function (migration and angiogenesis).

Discrepancies between nitroglycerin and NO-releasing drugs on mitochondrial oxygen consumption, vasoactivity, and the release of NO.

It has been generally acknowledged that the actions of glyceryl trinitrate (GTN) are a result of its bioconversion into NO. However, recent observations have thrown this idea into doubt, with many studies demonstrating that NO is present only when there are high concentrations of GTN. We have explored this discrepancy by developing a new approach that uses confocal microscopy to directly detect NO. Intracellular levels of NO in the rat aortic vascular wall have been compared with those present after incubation with 3 different NO donors (DETA-NO, 3-morpholinosydnonimine, and S-nitroso-N-acetylpenicillamine), endothelial activation with acetylcholine, or administration of GTN. We have also evaluated the relaxant effects of these treatments on isolated rings of aorta following activation of the enzyme soluble guanylyl cyclase and their inhibitory action on mitochondrial respiration, which is an index of the interaction of NO with the enzyme of the electron transport chain cytochrome C oxidase. In the case of the various NO donors and acetylcholine, we detected a concentration-dependent relationship in the intensity of vascular relaxation and degree of NO fluorescence and an increase in the Michaelis constant (Km) for O2. GTN did not produce similar effects, and although clinically relevant concentrations of this compound caused clear, concentration-related relaxations, there was neither any increase in NO-related fluorescence nor an augmented Km for O2. The nature of these differences suggests that these concentrations of GTN do not release free NO but probably a different species that, although it interacts with soluble guanylyl cyclase in vascular smooth muscle, does not inhibit O2 consumption by vascular mitochondria.

Changes in the expression of α1B-adrenoceptor in peripheral mononuclear cells correlates with blood pressure and plasmatic homocysteine.

Human peripheral mononuclear cells (HPMC) have been suggested as a practical surrogate for myocardial or vascular cells. Present work analyses if changes in the expression of α1-adrenoceptors (ARs) in HPMC are related to the hypertensive state and its clinical consequences. Quantitative RT-PCR was employed to evaluate the mRNA levels of the three α1-ARs (α1A, α1B, α1D) in HPMC isolated from normotensive and hypertensive patients, and also in tissues from two animal models of hypertension: spontaneously hypertensive rats (SHR) and hypertension induced by chronic treatment with L-NAME. In patients, 24-h ambulatory blood pressure and serum biochemical profile were also recorded. We found that α1B-AR expression was higher in HPMC from hypertensive patients and correlated with blood pressure and plasmatic homocysteine. A rise in the α1B-AR expression in kidneys, but not in heart from hypertensive animal models was also found. α1D-AR did not change in HPMC, not in rat heart or kidney, but a significant correlation with plasmatic aldosterone was found. In conclusion, we have proved that α1-ARs mRNA expression in HPMC correlates with clinical variables and could be used as a potential biomarker in hypertensive patients.

Activation of α1A -adrenoceptors desensitizes the rat aorta response to phenylephrine through a neuronal NOS pathway, a mechanism lost with ageing.

BACKGROUND AND PURPOSE: A NO-mediated desensitization of vasoconstrictor responses evoked by stimulation of α1 -adrenoceptors has been reported in different vessels. We investigated the involvement of each α1 -adrenoceptor subtype and constitutive NOS isoforms and the influence of ageing and hypertension on this process. EXPERIMENTAL APPROACH: Wistar and spontaneously hypertensive rats (SHR), 16, 32, 52 and 72 weeks-old, were used to evaluate the desensitization process. Expression of α1 -adrenoceptor subtypes, endothelial NOS (eNOS) and neuronal NOS (nNOS) were determined in rat aorta and left ventricle (LV). Expression levels were also evaluated in LV of a group of heart failure patients with a wide age range. KEY RESULTS: Repeated application of phenylephrine decreased subsequent α1 -adrenoceptor-mediated vasoconstriction by increasing nNOS protein expression in aorta, but not in tail or mesenteric resistance arteries, where mRNA levels of nNOS were undetectable. This desensitization process disappeared in the absence of endothelium or in the presence of L-NAME (100 µM), nNOS inhibitors, SMTC (1 µM) and TRIM (100 µM), and 5-methylurapidil (100 nM, α1A -antagonist), but not BMY7378 (10 nM, α1D -antagonist). The α1A /nNOS-mediated desensitization was absent in aged SHR and Wistar animals, where the expression of α1A -adrenoceptors was reduced in aorta and LV. In human LV, a negative correlation was found between age and α1A -adrenoceptor expression. CONCLUSIONS AND IMPLICATIONS: The α1A -adrenoceptor subtype, through endothelial nNOS-derived NO, may act as a physiological 'brake' against the detrimental effects of excessive α1 -adrenoceptor-mediated vasoconstriction. Reduced α1A -adrenoceptor- and nNOS-mediated desensitization in aged patients could be involved in the age-dependent elevation of adrenergic activity.