Morfinomiméticos : aspectos farmacodinámicos en Ileon de cobayo estimulado coaxialmente

Depto. de Biología CelularFac. de Ciencias BiológicasTRUEProQuestpu

Evidence that Nitric Oxide is Involved in the Blood Pressure Lowering Effect of the Peptide AVFQHNCQE in Spontaneously Hypertensive Rats

AVFQHNCQE is an antihypertensive nonapeptide obtained from a chicken foot protein hydrolysate. The present study aims to investigate the mechanisms involved in its blood pressure (BP)-lowering effect. Male (17–20 weeks old) spontaneously hypertensive rats (SHR) were used in this study. Rats were divided into two groups and orally administered water or 10 mg/kg body weight (bw) AVFQHNCQE. One hour post administration, animals of both groups were intra peritoneally treated with 1 mL of saline or with 1 mL of saline containing 30 mg/kg bw Nω-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide (NO) synthesis, or with 1 mL of saline containing 5 mg/kg bw indomethacin, which is an inhibitor of prostacyclin synthesis (n = 6 per group). Systolic BP was recorded before oral administration and six hours after oral administration. In an additional experiment, SHR were administered water or 10 mg/kg bw AVFQHNCQE (n = 6 per group) and sacrificed six hours post administration to study the mechanisms underlying the peptide anti-hypertensive effect. Moreover, the relaxation caused by AVFQHNCQE in isolated aortic rings from Sprague Dawley rats was evaluated. The BP-lowering effect of the peptide was not changed after indomethacin administration but was completely abolished by L-NAME, which demonstrates that its anti-hypertensive effect is mediated by changes in endothelium-derived NO availability. In addition, AVFQHNCQE administration downregulated aortic gene expression of the vasoconstrictor factor endothelin-1 and the endothelial major free radical producer NADPH. Moreover, while no changes in plasma ACE activity were observed after its administration, liver GSH levels were higher in the peptide treated group than in the water group, which demonstrates that AVFQHNCQE presents antioxidant properties

Plan de formación docente de jóvenes investigadores pre- y postdoctorales del Departamento de Farmacología y Toxicología.

Los objetivos que se han alcanzado son los siguientes: 1. Teniendo en cuenta los resultados obtenidos durante el curso 2018-19 (además de los resultados obtenidos en el curso 2017-18) los participantes han alcanzado una formación por encima de lo esperado en Farmacología habiendo asistido a una media de 57% del curso en su primer año de participación (cuando lo estipulado en el Plan de Formacion Docente es del 30%). Además, han superado un 42,3% de la materia entre su primer y segundo año con una calificación media de 8,3. 2. Los jóvenes investigadores han realizado una media de 10 horas de prácticas docentes contabilizando aquellas dedicadas a la asistencia a prácticas como oyentes, el ensayo de las prácticas con tutores y la impartición misma de las sesiones de prácticas. El número de horas está muy limitado por el bajo número de horas prácticas en las asignaturas de Farmacología del Dpto. y el elevado número de jóvenes investigadores incorporados al Dpto. 3. Con todo lo anterior, los jóvenes investigadores han alcanzado la formación en competencias docentes y las horas realizadas han sido acreditadas a las respectivas autoridades de sus becas/contratos. Su participación en la docencia práctica les permitirá en el futuro solicitar un certificado de actividades docentes emitido por las autoridades académicas de la Facultad de Medicina que avalaran su experiencia docente en solicitudes de acreditación a las diferentes figuras de profesor ante la ANECA. Además, el Dpto. de Farmacología y Toxicología ha emitido informes detallados de Aptitud Docente en Farmacología reflejando su participación en el Plan de Formación Docente del Dpto. que podrán ser consideradas en solicitudes a puestos docentes en el futuro

Inhibition of Gastric Lipase as a Mechanism for Body Weight and Plasma Lipids Reduction in Zucker Rats Fed a Rosemary Extract Rich in Carnosic Acid

BACKGROUND: Rosemary (Rosmarinus officinalis L.) extracts (REs) exhibit hepatoprotective, anti-obesity and anti-inflammatory properties and are widely used in the food industry. REs are rich in carnosic acid (CA) and carnosol which may be responsible for some of the biological activities of REs. The aim of this study was to investigate whether inhibition of lipase activity in the gut may be a mechanism by which a RE enriched in CA (40%) modulates body weight and lipids levels in a rat model of metabolic disorders and obesity. METHODS AND PRINCIPAL FINDINGS: RE was administered for 64 days to lean (fa/+) and obese (fa/fa) female Zucker rats and body weight, food intake, feces weight and blood biochemical parameters were monitored throughout the study. Lipase activity (hydrolysis of p-nitrophenylbutyrate) was measured in the gastrointestinal tract at the end of the study and the contents of CA, carnosol and methyl carnosate were also determined. Sub-chronic administration of RE moderately reduced body weight gain in both lean and obese animals but did not affect food intake. Serum triglycerides, cholesterol and insulin levels were also markedly decreased in the lean animals supplemented with RE. Importantly, lipase activity was significantly inhibited in the stomach of the RE-supplemented animals where the highest content of intact CA and carnosol was detected. CONCLUSIONS: Our results confirm that long-term administration of RE enriched in CA moderates weight gain and improves the plasma lipids profile, primarily in the lean animals. Our data also suggest that these effects may be caused, at least in part, by a significant inhibition of gastric lipase and subsequent reduction in fat absorption

Insulin-Regulated Srebp-1c and Pck1 mRNA Expression in Primary Hepatocytes from Zucker Fatty but Not Lean Rats Is Affected by Feeding Conditions

Insulin regulates the transcription of genes for hepatic glucose and lipid metabolism. We hypothesized that this action may be impaired in hepatocytes from insulin resistant animals. Primary hepatocytes from insulin sensitive Zucker lean (ZL) and insulin resistant Zucker fatty (ZF) rats in ad libitum or after an overnight fasting were isolated, cultured and treated with insulin and other compounds for analysis of gene expression using real-time PCR. The mRNA levels of one insulin-induced (Srebp-1c) and one insulin-suppressed (Pck1) genes in response to insulin, glucagon, and compactin treatments in hepatocytes from ad libitum ZL and ZF rats were analyzed. Additionally, the effects of insulin and T1317 on their levels in hepatocytes from ad libitum or fasted ZL or ZF rats were compared. The mRNA levels of Srebp-1c, Fas, and Scd1, but not that of Insr, Gck and Pck1, were higher in freshly isolated hepatocytes from ad libitum ZF than that from ZL rats. These patterns of Srebp-1c and Pck1 mRNA levels remained in primary hepatocyte cultured in vitro. Insulin's ability to regulate Srebp-1c and Pck1 expression was diminished in hepatocytes from ad libitum ZF, but not ZL rats. Glucagon or compactin suppressed Srebp-1c mRNA expression in lean, but not fatty hepatocytes. However, glucagon induced Pck1 mRNA expression similarly in hepatocytes from ad libitum ZL and ZF rats. Insulin caused the same dose-dependent increase of Akt phosphorylation in hepatocytes from ad libitum ZL and ZF rats. It synergized with T1317 to induce Srebp-1c, and suppressed Pck1 mRNA levels in hepatocytes from fasted, but not that from ad libitum ZF rats. We demonstrated that insulin was unable to regulate its downstream genes' mRNA expression in hepatocytes from ad libitum ZF rats. This impairment can be partially restored in hepatocytes from ZF rats after an overnight fasting, a phenomenon that deserves further investigation

Dose-Related Antihypertensive Properties and the Corresponding Mechanisms of a Chicken Foot Hydrolysate in Hypertensive Rats

The antihypertensive properties of different doses of a chicken foot hydrolysate, Hpp11 and the mechanisms involved in this effect were investigated. Spontaneously hypertensive rats (SHR) were administered water, Captopril (50 mg/kg) or Hpp11 at different doses (25, 55 and 85 mg/kg), and the systolic blood pressure (SBP) was recorded. The SBP of normotensive Wistar-Kyoto (WKY) rats administered water or Hpp11 was also recorded. Additionally, plasmatic angiotensin-converting enzyme (ACE) activity was determined in the SHR administered Hpp11. Moreover, the relaxation caused by Hpp11 in isolated aortic rings from Sprague-Dawley rats was evaluated. Hpp11 exhibited antihypertensive activity at doses of 55 and 85 mg/kg, with maximum activity 6 h post-administration. At this time, no differences were found between these doses and Captopril. Initial SBP values of 55 and 85 mg/kg were recovered 24 or 8 h post-administration, respectively, 55 mg/kg being the most effective dose. At this dose, a reduction in the plasmatic ACE activity in the SHR was found. However, Hpp11 did not relax the aortic ring preparations. Therefore, ACE inhibition could be the mechanism underlying Hpp11 antihypertensive effect. Remarkably, Hpp11 did not modify SBP in WKY rats, showing that the decreased SBP effect is specific to the hypertensive state

Antioxidant, Angiotensin-Converting Enzyme Inhibitory Properties and Blood-Pressure-Lowering Effect of Rice Bran Protein Hydrolysates

This research aimed to investigate the biological properties of different hydrolysates derived from industrial and laboratory defatted rice bran proteins. Industrial and laboratory defatted rice bran protein concentrates were hydrolyzed with alcalase or flavorzyme. The degree of hydrolysis (DH), oxygen radical absorbance capacity (ORAC), reducing power, total phenolic compounds (TPC), and angiotensin-converting enzyme (ACE) inhibitory activity, were determined in the hydrolysates and the molecular fractions lower than 3 kDa. Systolic blood pressure (SBP) was measured using the tail-cuff method before and after oral administration of 80 mg/kg of different rice bran protein hydrolysate (RBPH) fractions lower than 3 kDa in male spontaneously hypertensive rats (SHR) and normotensive Wistar–Kyoto (WKY) rats. The highest values of in vitro antioxidant activity and TPC were observed in RBPH with alcalase defatted by industry (RBPH2A), and, in all cases, these bioactivities were higher in the molecular fractions lower than 3 kDa. Once again, fractions lower than 3 kDa obtained with alcalase showed a potent ACE inhibitory activity (RBPH1A<3). The administration of RBPH1A<3 caused a significant decrease in the SBP in SHR, where the maximum decrease was reached at 8 h after administration. SBP in WKY rats was not modified after the administration of RBPH1A<3. These results suggest that the rice bran protein hydrolysates obtained from industry after treatment with alcalase could be an interesting source of bioactive peptides, with potential action on hypertension and other related pathologies