Jaqueline da Silva

Characterization of the cardiac renin angiotensin system in oophorectomized and estrogen-replete mRen2.Lewis rats.

The cardioprotective effects of estrogen are well recognized, but the mechanisms remain poorly understood. Accumulating evidence suggests that the local cardiac renin-angiotensin system (RAS) is involved in the development and progression of cardiac hypertrophy, remodeling, and heart failure. Estrogen attenuates the effects of an activated circulating RAS; however, its role in regulating the cardiac RAS is unclear. Bilateral oophorectomy (OVX; n = 17) or sham-operation (Sham; n = 13) was performed in 4-week-old, female mRen2.Lewis rats. At 11 weeks of age, the rats were randomized and received either 17 β-estradiol (E2, 36 µg/pellet, 60-day release, n = 8) or vehicle (OVX-V, n = 9) for 4 weeks. The rats were sacrificed, and blood and hearts were used to determine protein and/or gene expression of circulating and tissue RAS components. E2 treatment minimized the rise in circulating angiotensin (Ang) II and aldosterone produced by loss of ovarian estrogens. Chronic E2 also attenuated OVX-associated increases in cardiac Ang II, Ang-(1–7) content, chymase gene expression, and mast cell number. Neither OVX nor OVX+E2 altered cardiac expression or activity of renin, angiotensinogen, angiotensin-converting enzyme (ACE), and Ang II type 1 receptor (AT1R). E2 treatment in OVX rats significantly decreased gene expression of MMP-9, ACE2, and Ang-(1–7) mas receptor, in comparison to sham-operated and OVX littermates. E2 treatment appears to inhibit upsurges in cardiac Ang II expression in the OVX-mRen2 rat, possibly by reducing chymase-dependent Ang II formation. Further studies are warranted to determine whether an E2-mediated reduction in cardiac chymase directly contributes to this response in OVX rats.

LASSBio-294, A Compound With Inotropic and Lusitropic Activity, Decreases Cardiac Remodeling and Improves Ca2+ Influx Into Sarcoplasmic Reticulum After Myocardial Infarction

BACKGROUND Myocardial infarction (MI) is commonly associated with cardiac hypertrophy, reduced Ca²(+) uptake into the sarcoplasmic reticulum (SR) and impaired myocardial relaxation. Treatment to prevent MI-associated complications is currently lacking. The purpose of the present study was to investigate the remodeling and function of hearts subjected to experimental MI and to evaluate the response to treatment with a new thienylhydrazone: 3,4-methylenedioxybenzoyl-2-thienylhydrazone (LASSBio-294), which has demonstrated positive inotropic properties. METHODS LASSBio-294 (2 mg/kg) or vehicle (dimethyl sulfoxide) was administered daily by intraperitoneal injection for 4 weeks in sham-operated rats and rats with MI. Cardiac remodeling and hemodynamic parameters were monitored through histological and intraventricular pressure analyses. Intracellular Ca²(+) regulation (uptake and release) and the sensitivity of contractile proteins to Ca²(+) were evaluated by determining the contractile response of saponin-skinned cardiac cells from infarcted hearts. RESULTS Cardiac hypertrophy occurred at 4 weeks post-MI and was partially reverted by treatment with LASSBio-294. LASSBio-294 treatment also reduced the nuclear density, collagen volume fraction, and left ventricular end-diastolic pressure (LV EDP) induced by MI. MI led to reduced Ca²(+) uptake from the SR, but did not modify the Ca²(+) release or the Ca²(+)-force relationship. LASSBio-294 restored SR function and enhanced the sensitivity of contractile proteins to Ca²(+). CONCLUSION LASSBio-294 is a promising candidate for improving intracellular Ca²(+) regulation and preventing MI-induced cardiac dysfunction, which could potentially prevent heart failure (HF).

Illicit drug use in seven Latin American countries: critical perspectives of families and familiars

This cross-sectional multi-centre study explored how family members and friends of illicit drug users perceived protective and risk factors, treatment facilities and policies and laws regarding illicit drug use. Family members and friends of illicit drug users were recruited in 10 urban health care outpatient units in 7 Latin American countries (Brazil, Colombia, Costa Rica, Ecuador, Guatemala, Honduras and Mexico) to complete a questionnaire. The majority of the respondents chose psycho-social factors over genetic or biological explanations as causes of drug problems. Respondents felt that families and governments were responsible for preventing drug problems. Church/religious institutions were most often mentioned in the context of accessible treatment. When asked about access to treatment facilities, the majority said that there were not enough. Shame about drug use, cost, and limited treatment options were most often cited as barriers to treatment.Este estudo multicentrico corte temporal explorou a perspectiva de familiares e pessoas proximas a usuarios de drogas ilicitas sobre fatores de risco e protecao, servicos de tratamento, politicas e leis relacionadas ao uso de drogas ilicitas. Os familiares e pessoas proximas a usuarios de drogas ilicitas foram recrutados em dez unidades de saude, localizadas em grandes centros urbanos de sete paises da America Latina (Brasil, Colombia, Costa Rica, Equador, Guatemala, Honduras e Mexico), para responderem um questionario. A maioria dos participantes escolheu fatores psicossociais e nao fatores geneticos ou biologicos para explicar a causa dos problemas do uso de drogas. Responderam que familiares e governantes sao os principais responsaveis pela prevencao dos problemas das drogas. As igrejas e outras instituicoes religiosas foram mencionadas com frequencia dentro do contexto de acesso ao tratamento. A maioria dos entrevistados apontou que o acesso aos servicos que oferecem tratamentos aos usuarios de drogas nao e suficiente. Vergonha sobre o uso de drogas, custo e opcoes insuficientes de tratamento foram citados com mais frequencia como as principais barreiras para o tratamento.

Effect of Age, Estrogen Status, and Late-Life GPER Activation on Cardiac Structure and Function in the Fischer344×Brown Norway Female Rat

Age-associated changes in cardiac structure and function, together with estrogen loss, contribute to the progression of heart failure with preserved ejection fraction in older women. To investigate the effects of aging and estrogen loss on the development of its precursor, asymptomatic left ventricular diastolic dysfunction, echocardiograms were performed in 10 middle-aged (20 months) and 30 old-aged (30 months) female Fischer344×Brown-Norway rats, 4 and 8 weeks after ovariectomy (OVX) and sham procedures (gonads left intact). The cardioprotective potential of administering chronic G1, the selective agonist to the new G-protein-coupled estrogen receptor (GPER), was further evaluated in old rats (Old-OVX+G1) versus age-matched, vehicle-treated OVX and gonadal intact rats. Advanced age and estrogen loss led to decreases in myocardial relaxation and elevations in filling pressure, in part, due to reductions in phosphorylated phospholamban and increases in cardiac collagen deposition. Eight weeks of G-protein-coupled estrogen receptor activation in Old-OVX+G1 rats reversed the adverse effects of age and estrogen loss on myocardial relaxation through increases in sarcoplasmic reticulum Ca2+ ATPase expression and reductions in interstitial fibrosis. These findings may explain the preponderance of heart failure with preserved ejection fraction in older postmenopausal women and provide a promising, late-life therapeutic target to reverse or halt the progression of left ventricular diastolic dysfunction.

Benzenesulfonamide attenuates monocrotaline-induced pulmonary arterial hypertension in a rat model.

In this study, we examined the effects of LASSBio-965 (N-[2-(3,4-dimethoxyphenyl) ethyl]-benzenesulfonamide), a compound designed as a simplified structure of a non-selective phosphodiesterase 4 inhibitor, on vascular smooth muscle in vitro as well as in a rat model of monocrotaline (MCT)-induced pulmonary arterial hypertension. LASSBio-965 (50 mg/kg) treatment caused a significant decrease in right systolic ventricular pressure (32.47 ± 3.09 mmHg) compared to the MCT-vehicle group (51.88 ± 3.23 mmHg; P<0.05) and in the ratio of right ventricular weight to left ventricular weight plus septum (0.42 ± 0.03 g compared to 0.59 ± 0.06 g, respectively; MCT-vehicle group; P<0.05). LASSBio-965 induced a concentration-dependent relaxation of rat aortic rings, which was decreased by mechanical removal of the endothelium. Milrinone, rolipram, and sildenafil reduced the maximum relaxation (100%) to 22.4 ± 5.8, 69.5 ± 5.6 and 80.1 ± 10.7%, respectively (P<0.05). Maximum relaxation responses of aortic and pulmonary artery rings were decreased in the MCT-vehicle group (54.80 ± 5.69 and 35.87 ± 4.78, respectively) compared to the control (91.51 ± 4.79 and 54.32 ± 2.39, respectively) but improved with LASSBio-965 treatment (50mg/kg; 88.43 ± 4.54 and 59.36 ± 4.83, respectively). These results indicate that LASSBio-965 can attenuate the pulmonary arterial hypertension in an animal model most likely through the nonselective inhibition of phosphodiesterases 3, 4, and 5.

Pharmacological Activity of Novel 2-hydroxyacetophenone Isatin Derivatives on Cardiac and Vascular Smooth Muscles in Rats

Isatin (1H-indole-2,3 dione) is an endogenous compound with biological activities. Many of its derivatives have pharmacological effects, including inhibition of cyclic guanosine monophosphate levels in cardiac tissue; sedative-hypnotic profiles; anticonvulsant, analgesic, antithermic, and anti-inflammatory activities; and anxiolytic, antimicrobial, and proapoptotic effects. Carbamates derived from isatin have a vasorelaxant profile. This study investigated the activity of 2 novel 2-hydroxyacetophenone derivatives of isatin (named MB101 and MB130) on the contractility of rat aorta and papillary muscles. Both compounds induced a concentration-dependent relaxation (5-100 μM) in the endothelium-intact aorta that was abolished by N-nitro-L-arginine methyl ester. Atropine, a muscarinic receptor antagonist, significantly prevented vasodilatation of 100 μM MB101. In contrast, atropine caused no significant alteration in MB130-induced vasorelaxation. Naloxone, a nonselective opioid receptor antagonist, completely prevented the relaxing effect of MB101 and MB130 at all concentrations. In papillary muscles, only MB130 induced a significant depression, and this contractile response was not altered by propranolol and atropine. Both the compounds reduced systolic and diastolic pressures in a dose-dependent manner in anesthetized rats. The 2-hydroxyacetophenones produced direct effects on vascular tonus through either muscarinic or opioid pathways. MB130 produced cardiac depression by opioid receptors and bradykinin because pretreatment HOE140 or with naloxone, an antagonist of type-2, bradykinin were able to partially block the decrease in twitch amplitude in papillary muscles induced by MB130. These findings provide information for designing new strategies for the treatment of cardiovascular disorders.

Adenosine A 2A receptor agonist prevents cardiac remodeling and dysfunction in spontaneously hypertensive male rats after myocardial infarction

Background This work evaluated the hypothesis that 3,4-methylenedioxybenzoyl-2-thienylhydrazone (LASSBio-294), an agonist of adenosine A2A receptor, could be beneficial for preventing cardiac dysfunction due to hypertension associated with myocardial infarction (MI). Methods Male spontaneously hypertensive rats (SHR) were randomly divided into four groups (six animals per group): sham-operation (SHR-Sham), and myocardial infarction rats (SHR-MI) were treated orally either with vehicle or LASSBio-294 (10 and 20 mg.kg−1.d−1) for 4 weeks. Echocardiography and in vivo hemodynamic parameters measured left ventricle (LV) structure and function. Exercise tolerance was evaluated using a treadmill test. Cardiac remodeling was accessed by LV collagen deposition and tumor necrosis factor α expression. Results Early mitral inflow velocity was significantly reduced in the SHR-MI group, and there was significant recovery in a dose-dependent manner after treatment with LASSBio-294. Exercise intolerance observed in the SHR-MI group was prevented by 10 mg.kg−1.d−1 of LASS-Bio-294, and exercise tolerance exceeded that of the SHR-Sham group at 20 mg.kg−1.d−1. LV end-diastolic pressure increased after MI, and this was prevented by 10 and 20 mg.kg−1.d−1 of LASSBio-294. Sarcoplasmic reticulum Ca2+ ATPase levels were restored in a dose-dependent manner after treatment with LASSBio-294. Fibrosis and inflammatory processes were also counteracted by LASSBio-294, with reductions in LV collagen deposition and tumor necrosis factor α expression. Conclusion In summary, oral administration of LASSBio-294 after MI in a dose-dependent manner prevented the development of cardiac dysfunction, demonstrating this compound’s potential as an alternative treatment for heart failure in the setting of ischemic heart disease with superimposed chronic hypertension.

synthesis, solubility, plasma stability, and pharmacological evaluation of novel sulfonylhydrazones designed as anti-diabetic agents

Neuropathy is a serious complication of diabetes that has a significant socioeconomic impact, since it frequently demands high levels of health care consumption and compromises labor productivity. Recently, LASSBio-1471 (3) was demonstrated to improve oral glucose tolerance, reduce blood glucose levels, and display an anti-neuropathy effect in a murine streptozotocin-induced diabetes model. In the present work, we describe the design, synthesis, solubility, plasma stability, and pharmacological evaluation of novel sulfonylhydrazone derivatives (referred to herein as compounds 4–9), which were designed by molecular modification based on the structure of the prototype LASSBio-1471 (3). Among the compounds tested, better plasma stability was observed with 4, 5, and 9 in comparison to compounds 6, 7, and 8. LASSBio-1773 (7), promoted not only hypoglycemic activity but also the reduction of thermal hyperalgesia and mechanical allodynia in a murine model of streptozotocin-induced diabetic neuropathic pain.

N-acylhydrazone improves exercise intolerance in rats submitted to myocardial infarction by the recovery of calcium homeostasis in skeletal muscle.

AIMS This work investigated the effects of 3,4-methylenedioxybenzoyl-2-thienylhydrazone (LASSBio-294) treatment on the contractile response of soleus (SOL) muscle from rats submitted to myocardial infarction (MI). MAIN METHODS Following coronary artery ligation, LASSBio-294 (2mg/kg, i.p.) or vehicle was administrated once daily for 4 weeks. KEY FINDINGS The run time to fatigue for sham rats was 17.9 ±2.6 min, and it was reduced to 3.3 ± 0.8 min (P<0.05) in MI rats. In MI rats treated with LASSBio-294, the time to fatigue was 15.1 ± 3.6 min. During the contractile test, SOL muscles from sham rats showed a response of 7.12 ± 0.54N/cm(2) at 60 Hz, which was decreased to 5.45 ± 0.49 N/cm(2) (P<0.05) in MI rats. The contractility of SOL muscles from the MI-LASSBio-294 group was increased to 9.01 ± 0.65N/cm(2). At 16 mM caffeine, the contractility was reduced from 2.31 ± 0.33 to 1.60 ± 0.21 N/cm(2) (P<0.05) in the MI group. In SOL muscles from MI-LASSBio-294 rats, the caffeine response was increased to 2.62 ± 0.33 N/cm(2). Moreover, SERCA2a expression in SOL muscles was decreased by 0.31-fold (31%) in the MI group compared to the Sham group (P<0.05). In the MI-LASSBio-294 group, it was increased by 1.53-fold (153%) compared to the MI group (P<0.05). Meanwhile, the nuclear density in SOL muscles was increased in the MI group compared to the Sham group. Treatment with LASSBio-294 prevented this enhancement of cellular infiltrate. SIGNIFICANCE LASSBio-294 treatment prevented the development of muscular fatigue and improved exercise intolerance in rats submitted to MI.

Novel Partial Agonist of PPAR-Gamma for Treatment of Diabetic Neuropathy in Rats

This work describes a novel ligand for peroxisome proliferator-activated receptor gamma (PPARgamma) and its hypoglycemic and analgesic activity in a murine model of diabetes-induced neuropathic pain. The molecular recognition of LASSBio-1772 by a PPARgamma binding domain showed that the compound is a partial agonist. Four weeks after male Wistar rats received a single intravenous injection of streptozotocin (STZ, 60 mg/kg), plasma glucose levels were increased from 92.5 ± 3.7 to 465.0 ± 21.6 mg/dL (P < 0.01) and serum insulin was reduced from 66.8 ± 7.8 to 25.5 ± 5.6 pmol/L (P<0.01). Diabetic animals were then, treated with either vehicle or LASSBio-1772 (50 mg/kg, i.p.) daily for 7 days. LASSBio-1772 significantly reduced blood glucose levels to 242.0 ± 55.1 mg/dL (P<0.05) and increased insulin levels to 58.7 ± 14.8 pmol/L (P<0.05), indicating the hypoglycemic activity of this compound. LASSBio-1772 also reduced the elevated triglyceride levels induced by STZ treatment from 74.1 ± 8.6 to 34.0 ± 6.3 mg/dL (P<0.01). LASSBio-1772 could reduce serum glucose levels via increased insulin levels and potentially improve insulin sensitivity. Neuropathy was detected after four weeks of STZ-induced diabetes, with reduced thermal heat withdrawal latency from 11.7 ± 0.1 to 7.1 ± 0.2 s (P<0.01) and paw withdrawal threshold from 37.5 ± 2.1 to 29.9 ± 1.1 g (P<0.05) indicating the establishment of hyperalgesia and allodynia. LASSBio-1772 treatment restored both measures to non-diabetic values (12.2 ± 0.4 s and 34.5 ± 1.5 g). In conclusion, treatment with LASSBio-1772, a partial PPARgamma agonist, decreased hyperglycemia and neuropathic pain induced by diabetes. PPARgamma stimulation by LASSBio-1772 could prevent inflammation and inhibit both peripheral and central sensitization.