Pharmacokinetic and pharmacodynamic evaluation of nitro-enalapril (NCX899)

Orientador: Gilberto de NucciTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias MedicasResumo: Compostos farmacológicos que liberam óxido nítrico (NO) têm sido utilizados para avaliar o amplo papel do NO na fisiopatologia e terapêutica de diversas doenças. Estudos demonstram que a deficiência de NO está envolvida com a gênese e evolução de diversos estágios de doenças como, por exemplo, a hipertensão. Deste modo, a adição de uma molécula de NO em drogas previamente estudadas vem sendo praticada por diversos pesquisadores na última década. Estes pesquisadores buscam associar as propriedades farmacológicas de cada droga com as atividades proporcionadas pelo NO exógeno. No presente trabalho, comparamos a farmacocinética e a farmacodinâmica do enalapril com as de um nitro-derivado do enalapril (NCX899), em Beagles machos não anestesiados. Os efeitos do enalapril e NCX899 na hipertensão arterial, bradicardia e vasoconstrição periférica induzida pela inibição aguda da síntese de NO em cães anestesiados também foram investigados. Na avaliação farmacocinética, os cães receberam NCX899 (4 µmol/Kg) ou Enalapril (4 µmol/Kg) pela via intravenosa. Em seguida, as concentrações plasmáticas dos analitos e metabólitos foram quantificadas pelo método de cromatografia líquida de alta eficiência, acoplada à espectrometria de massa (LCMS- MS). No grupo NCX899, a área sob a curva (ASC0-24h) foi 29,18 ± 4,72, 229,37 ± 51,32 e 5159,23 ± 514,88 µgh/l para os analitos nitro-enalapril, enalapril e enalaprilato, respectivamente. No grupo Enalapril, a ASC0-24h foi de 704,53 ± 158,86 e 4149,27 ± 847,30 µgh/l para os analitos enalapril e enalaprilato, respectivamente. As análises estatísticas entre os grupos demonstraram uma diferença significativa para o analito enalapril, mas não para o analito enalaprilato, o metabólito ativo. Entretanto, o NCX899 e o Enalapril foram efetivos de maneira semelhante na inibição da atividade da enzima conversora de angiotensina sérica. Em cães anestesiados, a administração intravenosa do inibidor da síntese de NO, o N?-nitro-L-arginina metil éster (L-NAME; 0,1-10 mg/kg), elevou significativamente a pressão arterial e causou bradicardia. O composto NCX899 atenuou significativamente a hipertensão arterial, bradicardia e vasoconstrição periférica, enquanto o Enalapril não apresentou efeito significativo. Além disso, nossos estudos também demonstraram que o NCX899 pode atuar não só como anti-hipertensivo, mas também auxiliar na inibição da agregação plaquetária. Assim, concluímos que o nitro-derivado do enalapril (NCX899) apresenta uma relação farmacocinética/farmacodinâmica similar ao composto enalapril. No entanto, ao contrário do Enalapril, o NCX899 apresenta um efeito protetor nas alterações cardiovasculares induzidas pela inibição aguda de NOAbstract: Pharmacological compounds that release nitric oxide (NO) have been useful tools for evaluating the broad role of NO in physiopathology and therapeutics of several diseases. Studies show that lack of NO can cause several diseases such as hypertension. Thus, the addition of a NO molecule in drugs previously studied has been reported by some researchers in the last decade. They look for the combination of the pharmacologic properties of each drug, plus exogenous NO properties. This work has compared the pharmacokinetics and pharmacodynamics of enalapril and a NO-releasing enalapril molecule (NCX899) in conscious male Beagles. The effects of both enalapril and NCX899 in the arterial hypertension, bradycardia and peripheral vasoconstriction induced by acute NO inhibition in anesthetized dogs have also been investigated. In the pharmacokinetic evaluation, dogs received either NCX899 (4 µmol/Kg) or Enalapril (4 µmol/Kg) intravenously. Later, the plasma concentrations of the analytes and metabolites were quantified by liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS). In the NCX899 group, the area under time-course curve (AUC0-24h) was 29.18 ± 4.72, 229.37 ± 51.32 and 5159.23 ± 514.88 µgh/l for the nitro-enalapril, enalapril and enalaprilat analytes, respectively. In the Enalapril group, the AUC0-24h was 704.53 ± 158.86 and 4149.27 ± 847.30 µgh/l for the enalapril and enalaprilat analytes, respectively. The statistical analysis between both groups showed a significant difference for the enalapril analyte, but not for enalaprilat, the active metabolite. Moreover, NCX899 and Enalapril were equally effective on inhibiting the activity of serum angiotensin-converting enzyme. In anesthetized dogs, intravenous administration of the NO synthase (NOS) inhibitor N?-nitro-L-arginine methyl ester (L-NAME; 0.1-10 mg/kg) significantly elevated arterial blood pressure with concomitant bradycardia. The compound NCX899 significantly attenuated arterial hypertension, bradycardia and peripheral vasoconstriction, whereas Enalapril had no significant effect. In addition, our work showed that NCX899 also has properties of inhibiting the activity of platelets aggregation. In conclusion, our results showed that the NO-releasing derivative of enalapril NCX899 presents a pharmacokinetic / pharmacodynamic relationship similar to the enalapril compound. Moreover, different from Enalapril, NCX899 presented protective effect in the cardiovascular alterations induced by acute NOS inhibitionDoutoradoDoutor em Farmacologi

The importance of optimal 25-hydroxyvitamin D levels in the glycemic control of older adults with type 2 Diabetes Mellitus: Data from the study on aging and longevity EELO

Introduction: Optimal serum levels of vitamin D are of great importance, especially in populations with comorbidities such as Diabetes Mellitus (DM). Objective: The study evaluated the relationship between hypovitaminosis D and glycemic control in older adults with type 2 DM. Methods: Cross-sectional and prospective study, part of the EELO project (Study on Aging and Longevity), conducted in Southern Brazil. Glycated hemoglobin (diabetes ≥6.5%) and serum levels of vitamin D (25(OH)D) were evaluated. Hypovitaminosis D was determined using cutoff points <20 and <30 ng/mL). Multivariate logistic regression was used to assess the risk of having uncontrolled DM. Results: Of the 120 older adults included in the study, aged between 60 and 87 years, 74.2% were women, 66.7% used hypoglycemic medications and 75.8% exhibited uncontrolled diabetes. An inverse correlation was observed between the levels of 25(OH)D and glycated hemoglobin (rS=-0.19, p=0.037), suggesting that low levels of vitamin D are associated with poor glycemic control in diabetic individuals. The prevalence of hypovitaminosis D when using the cutoff points of <20 and <30 ng/mL were 34.2% and 75.0%, respectively. The odds ratio (OR) analysis showed that individuals with 25(OH)D<20ng/mL have almost 4 times more risk of having uncontrolled DM (OR:3.94; CI95%:1.25-12.46, p=0.02) when compared to the older adults with sufficient levels of vitamin D. Conclusion: The results indicate that the optimal serum levels currently recommended for 25(OH)D should preferably be 30 ng/mL or higher to contribute to better glycemic control in older adults with type 2 DM.