RESUMEN
Bioactive plant peptides have received considerable interest as potential antihypertensive agents with potentially fewer side effects than antihypertensive drugs. Here, the blood pressure-lowering effects of the Bowman-Birk protease inhibitor, BTCI, and its derived peptides, PepChy and PepTry, were investigated using normotensive (Wistar-WR) and spontaneously hypertensive rats (SHR). BTCI inhibited the proteases trypsin and chymotrypsin, respectively, at 6 µM and 40 µM, a 10-fold greater inhibition than observed with PepTry (60 µM) and PepChy (400 µM). These molecules also inhibited angiotensin converting enzyme (ACE) with IC50 values of 54.6 ± 2.9; 24.7 ± 1.1; and 24.4 ± 1.1 µM, respectively, occluding its catalytic site, as indicated by molecular docking simulation, mainly for PepChy and PepTry. Gavage administration of BTCI and the peptides promoted a decrease of systolic and diastolic blood pressure and an increase of renal and aortic vascular conductance. These effects were more expressive in SHR than in WR. Additionally, BTCI, PepChy and PepTry promoted coronary vasodilation and negative inotropic effects in isolated perfused hearts. The nitric oxide synthase inhibitor blunted the BTCI and PepChy, with no cardiac effects on PepTry. The findings of this study indicate a therapeutic potential of BTCI and its related peptides in the treatment of hypertension.
Asunto(s)
Antihipertensivos/farmacología , Presión Sanguínea/efectos de los fármacos , Hipertensión/tratamiento farmacológico , Contracción Miocárdica/efectos de los fármacos , Péptidos/farmacología , Inhibidor de la Tripsina de Soja de Bowman-Birk/farmacología , Animales , Antihipertensivos/química , Sitios de Unión , Quimotripsina/química , Quimotripsina/metabolismo , Vasos Coronarios/efectos de los fármacos , Vasos Coronarios/fisiopatología , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Hipertensión/enzimología , Hipertensión/fisiopatología , Masculino , Simulación del Acoplamiento Molecular , NG-Nitroarginina Metil Éster/química , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico Sintasa de Tipo III/antagonistas & inhibidores , Óxido Nítrico Sintasa de Tipo III/química , Óxido Nítrico Sintasa de Tipo III/metabolismo , Péptidos/síntesis química , Peptidil-Dipeptidasa A/química , Peptidil-Dipeptidasa A/metabolismo , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Estructura Secundaria de Proteína , Ratas , Ratas Endogámicas SHR , Ratas Wistar , Tripsina/química , Tripsina/metabolismo , Inhibidor de la Tripsina de Soja de Bowman-Birk/química , Vasodilatación/efectos de los fármacosRESUMEN
Micronutrient malnutrition during intrauterine and postnatal growth may program cardiovascular diseases in adulthood. We examined whether moderate zinc restriction in male and female rats throughout fetal life, lactation and/or postweaning growth induces alterations that can predispose to the onset of vascular dysfunction in adulthood. Female Wistar rats were fed low- or control zinc diets from pregnancy to offspring weaning. After weaning, offspring were fed either a low- or a control zinc diet until 81 days. We evaluated systolic blood pressure (SBP), thoracic aorta morphology, nitric oxide (NO) system and vascular reactivity in 6- and/or 81-day-old offspring. At day 6, zinc-deficient male and female offspring showed a decrease in aortic NO synthase (NOS) activity accompanied by an increase in oxidative stress. Zinc-deficient 81-day-old male rats exhibited an increase in collagen deposition in tunica media, as well as lower activity of endothelial NOS (eNOS) that could not be reversed with an adequate zinc diet during postweaning life. Zinc deficiency programmed a reduction in eNOS protein expression and higher SBP only in males. Adult zinc-deficient rats of both sexes showed reduced vasodilator response dependent on eNOS activity and impaired aortic vasoconstrictor response to angiotensin-II associated with alterations in intracellular calcium mobilization. Female rats were less sensitive to the effects of zinc deficiency and exhibited higher eNOS activity and/or expression than males, without alterations in SBP or aortic histology. This work strengthens the importance of a balanced intake of micronutrients during perinatal growth to ensure adequate vascular function in adult life.
Asunto(s)
Fenómenos Fisiológicos Nutricionales de los Animales , Desnutrición/complicaciones , Fenómenos Fisiologicos Nutricionales Maternos , Preñez , Enfermedades Vasculares/etiología , Zinc/deficiencia , Acetilcolina/química , Angiotensina II/química , Alimentación Animal , Animales , Aorta Torácica/metabolismo , Aorta Torácica/patología , Calcio/metabolismo , Femenino , Lactancia , Masculino , Micronutrientes , NG-Nitroarginina Metil Éster/química , Óxido Nítrico/química , Óxido Nítrico Sintasa/metabolismo , Nitroprusiato/química , Oxidantes/química , Estrés Oxidativo , Embarazo , Ratas , Ratas Wistar , Sístole , Enfermedades Vasculares/fisiopatología , Vasoconstrictores/química , Zinc/sangreRESUMEN
Carotid body chemoreceptors function as glucose sensors and contribute to glucose homeostasis. The nucleus tractus solitarii (NTS) is the first central nervous system (CNS) nuclei for processing of information arising in the carotid body. Here, we microinjected a nitric oxide (NO) donor sodium nitroprusside (SNP), an NO-independent activator of the soluble guanylyl cyclase (sGC) (YC1) or an NO-synthase (NOS) inhibitor Nω-nitro-l-arginine methyl ester (L-NAME) into the commissural NTS (cNTS) before carotid chemoreceptor anoxic stimulation and measured arterial glucose and the expression of Fos-like immunoreactivity (Fos-ir). Male Wistar rats (250-300 g) were anesthetized, and the carotid sinus was vascularly isolated. Either artificial cerebrospinal fluid (aCSF), SNP, YC1 or L-NAME were stereotaxically injected into the cNTS. The SNP and YC1 infused into the cNTS before carotid chemoreceptor stimulation (SNP-2 and YC1-2 groups) similarly increased arterial glucose compared to the aCSF-2 group. By contrast, infusion of L-NAME into the cNTS before carotid chemoreceptor stimulation (L-NAME-2 group) decreased arterial glucose concentration. The number of cNTS Fos-ir neurons, determined in all the groups studied except for YC1 groups, significantly increased in SNP-2 rat when compared to the aCSF-2 or SNP-2 groups. Our findings demonstrate that NO signaling, and the correlative activation of groups of cNTS neurons, plays key roles in the hyperglycemic reflex initiated by carotid chemoreceptor stimulation.
Asunto(s)
Cuerpo Carotídeo/metabolismo , Regulación de la Expresión Génica , Hiperglucemia/metabolismo , Óxido Nítrico/metabolismo , Proteínas Proto-Oncogénicas c-fos/metabolismo , Núcleo Solitario/metabolismo , Animales , Glucemia , Arterias Carótidas/efectos de los fármacos , Arterias Carótidas/metabolismo , Células Quimiorreceptoras/metabolismo , Glucosa/metabolismo , Homeostasis , Hipoxia , Masculino , NG-Nitroarginina Metil Éster/química , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Donantes de Óxido Nítrico/química , Nitroprusiato/química , Ratas , Ratas Wistar , Transducción de Señal , Cianuro de Sodio/químicaRESUMEN
Heme oxygenase (HO) has antioxidant properties and is up-regulated by reactive oxygen species (ROS) in ultraviolet-B-irradiated soybean plants. This study shows that nitric oxide (NO) protects against oxidative damage and that nitric oxide synthase (NOS)-like activity is also required for HO-1 induction under UV-B radiation. Pre-treatments with sodium nitroprussiate (SNP), a NO-donor, prevented chlorophyll loss, H(2)O(2) and O(2)(*-) accumulation, and ion leakage in UV-B-treated plants. HO activity was significantly enhanced by NO and showed a positive correlation with HO-1 transcript levels. In fact, HO-1 mRNA levels were increased 2.1-fold in 0.8 mM SNP-treated plants, whereas subsequent UV-B irradiation augmented this expression up to 3.5-fold with respect to controls. This response was not observed using ferrocyanide, a SNP inactive analog, and was effectively blocked by 2-(4-carboxyphenil)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO), a specific NO-scavenger. In addition, experiments carried out in the presence of N(G)-nitro-L-arginine methyl ester (L-NAME) or tungsten, well-known inhibitors of NOS and nitrate reductase, showed that NOS is the endogenous source of NO that mediates HO-1 expression. In summary, we found that NO is involved in the signaling pathway leading to HO-1 up-regulation under UV-B, and that a balance between NO and ROS is important to trigger the antioxidant response against oxidative stress.
Asunto(s)
Glycine max/metabolismo , Hemo Oxigenasa (Desciclizante)/metabolismo , Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico/biosíntesis , Rayos Ultravioleta , Clorofila/análisis , Clorofila/metabolismo , Clorofila/efectos de la radiación , Hemo Oxigenasa (Desciclizante)/efectos de la radiación , Peróxido de Hidrógeno/análisis , NG-Nitroarginina Metil Éster/química , Óxido Nítrico Sintasa/efectos de la radiación , Estrés Oxidativo/efectos de la radiación , Hojas de la Planta/química , Especies Reactivas de Oxígeno/análisis , Especies Reactivas de Oxígeno/metabolismo , Glycine max/genética , Glycine max/efectos de la radiación , Sustancias Reactivas al Ácido Tiobarbitúrico/análisisRESUMEN
INTRODUCTION: The aim of the work was to establish the impact of urethane-chloralose anaesthesia on pharmacokinetic-pharmacodynamic (PK-PD) properties of carvedilol in control rats and L-NAME hypertensive animals. METHODS: Male Wistar Rats were randomly divided into: control (n=12) with tap water to drink and L-NAME rats (n=12) with L-NAME solution (40 mg/kg/day) to drink for 2 weeks. Effects of carvedilol (1 mg kg(-1), i.v.) on blood pressure and heart rate were recorded during 3 h in conscious and urethane (500 mg kg(-1), i.p.) - chloralose (50 mg kg(-1), i.p.) anaesthetized rats. Carvedilol plasma pharmacokinetics was studied by means of traditional blood sampling. PK-PD modeling of carvedilol was made by means of an effect compartment model. RESULTS: Neither urethane-chloralose nor L-NAME modified estimation of pharmacokinetic parameters of carvedilol. Although urethane-chloralose did not modify potency of carvedilol comparing with awake animals in control and hypertensive group, maximal negative chronotropic response was significantly greater in anaesthetized L-NAME rats in comparison to awake animals. Conversely, anaesthesia did not modify maximal chronotropic response to carvedilol in control rats. Whilst no differences were found in the estimated potency of carvedilol hypotensive response comparing control and L-NAME rats in both awake and anaesthetized conditions, maximal hypotensive effect of carvedilol was significantly greater in anaesthetized control and L-NAME animals in comparison to conscious rats. L-NAME rats showed a greater maximal hypotensive response comparing to control group. DISCUSSION: Urethane-chloralose anaesthesia is an acceptable experimental condition for the evaluation of PK-PD properties of carvedilol, considering that it does not affect the potency of carvedilol for its chronotropic and hypotensive effect. Conclusions obtained from urethane-chloralose anaesthetized animals, regarding the impact of l-NAME treatment on PK-PD properties of carvedilol, did not differ from those obtained from conscious animals. Anaesthesia did not modify pharmacokinetic behaviour of carvedilol in both normotensive and L-NAME hypertensive rats.
Asunto(s)
Antagonistas Adrenérgicos beta/farmacocinética , Anestesia , Carbazoles/farmacocinética , Cloralosa/farmacocinética , Propanolaminas/farmacocinética , Uretano/farmacocinética , Administración Oral , Antagonistas Adrenérgicos beta/administración & dosificación , Antagonistas Adrenérgicos beta/sangre , Algoritmos , Animales , Área Bajo la Curva , Presión Sanguínea/efectos de los fármacos , Carbazoles/administración & dosificación , Carbazoles/sangre , Carvedilol , Cloralosa/administración & dosificación , Interpretación Estadística de Datos , Modelos Animales de Enfermedad , Esquema de Medicación , Sinergismo Farmacológico , Semivida , Frecuencia Cardíaca/efectos de los fármacos , Hipertensión/inducido químicamente , Inyecciones Intraperitoneales , Inyecciones Intravenosas , Masculino , Modelos Biológicos , NG-Nitroarginina Metil Éster/efectos adversos , NG-Nitroarginina Metil Éster/química , Propanolaminas/administración & dosificación , Propanolaminas/sangre , Ratas , Ratas Wistar , Soluciones/química , Uretano/administración & dosificaciónRESUMEN
The possible participation of the nitric oxide (NO)-cyclic GMP-protein kinase G (PKG) pathway on gabapentin-induced spinal antiallodynic activity was assessed in spinal nerve injured rats. Intrathecal gabapentin, diazoxide or pinacidil reduced tactile allodynia in a dose-dependent manner. Pretreatment with NG-L-nitro-arginine methyl ester (L-NAME, non-specific inhibitor of NO synthase NOS), 7-nitroindazole (neuronal NO synthase inhibitor), 1H-[1,2,4] -oxadiazolo [4,3-a] quinoxalin-1-one (ODQ, guanylyl cyclase inhibitor) or (9S, 10R, 12R)-2,3,9,10,11,12-hexahydro-10-methoxy-2,9-dimethyl-1-oxo-9,12-epoxy-1H-diindolo-[1,2,3-fg:3',2',1'-kl]pyrrolo[3,4-i][1,6]benzodiazocine-10-carboxylic acid methyl ester (KT-5823, specific PKG inhibitor), but not NG-D-nitro-arginine methyl ester (D-NAME) or okadaic acid (protein phosphatase 1 and 2 inhibitor) prevented gabapentin-induced antiallodynia. Pinacidil activity was not blocked by L-NAME, D-NAME, 7-nitroindazole, ODQ, KT-5823 or okadaic acid. Moreover, KT-5823, glibenclamide (ATP-sensitive K+ channel blocker), apamin and charybdotoxin (small- and large-conductance Ca2+-activated K+ channel blockers, respectively), but not margatoxin (voltage-gated K+ channel blocker), L-NAME, 7-nitroindazole, ODQ or okadaic acid, reduced diazoxide-induced antiallodynia. Data suggest that gabapentin-induced spinal antiallodynia could be due to activation of the NO-cyclic GMP-PKG-K+ channel pathway.