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1.
Poult Sci ; 98(8): 3304-3312, 2019 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-30941414

RESUMEN

Five hundred and forty 19-wk-old HyLine Brown laying hens were randomly distributed to 6 dietary treatments and fed 1of 6 corn-soybean meal-based diets added into choline with 0, 425, 850, 1,700, 3,400, and 6,800 mg/kg to investigate effects of dietary choline supplementation on lipid profiles of egg yolk, serum and liver, and hepatic redox status of laying hens. Yolk weight and total lipid, triglyceride, cholesterol and phosphatidylcholine, serum triglyceride, cholesterol, apolipoprotein B 100 (apoB 100), and very low density lipoprotein (VLDL), and liver relative weight, total lipid, triglyceride and apoB 100 as well as hepatic total superoxide dismutase and glutathione peroxidase (GSH-Px) activities, total antioxidant capacity (T-AOC), and malondialdehyde (MDA) in laying hens at weeks 58 and 68 of age were determined. The differences (P < 0.001) were caused by choline treatments in yolk phosphatidylcholine (at 850 mg/kg or more choline), serum VLDL, and liver triglyceride (at 1,700 and 3,400 mg/kg choline) of birds, at weeks 58 and 68 of age, and yolk total lipids were elevated (P < 0.05) by supplemental choline at 3,400 mg/kg whereas liver total lipids were reduced (P < 0.05) by 1,700 and 3,400 mg/kg choline addition. Hens fed diets supplemented choline had higher (P = 0.005) liver GSH-Px activity (with 3,400 mg/kg choline) and greater (P = 0.014) T-AOC (with 1,700 mg/kg choline) than those fed diets with 0 and 425 mg/kg choline addition. Choline affected serum VLDL, liver total lipid, triglyceride and apoB 100 at weeks 58 and 68 of age and hepatic GSH-Px activity, T-AOC and MDA at week 68 of age quadratically (P < 0.05), whereas it influenced total lipid and phosphatidylcholine of egg yolk linearly (P < 0.05) and quadratically (P < 0.05). In conclusion, dietary choline supplementation elevated yolk total lipid and phosphatidylcholine and serum VLDL, reduced liver total lipid and triglyceride, and enhanced hepatic GSH-Px activity and T-AOC in laying hens.


Asunto(s)
Alimentación Animal/análisis , Colina/farmacología , Yema de Huevo/química , Lípidos/sangre , Animales , Pollos , Dieta/veterinaria , Femenino , Glutatión Peroxidasa/análisis , Metabolismo de los Lípidos/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/enzimología , Hígado/metabolismo , Oxidación-Reducción/efectos de los fármacos , Fosfatidilcolinas/análisis , Distribución Aleatoria , Superóxido Dismutasa/análisis
2.
Poult Sci ; 97(7): 2460-2472, 2018 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-29669020

RESUMEN

Two hundred and sixteen 28-wk-old Hy-line laying hens were randomly distributed to three dietary treatments and fed 1of 3 diets containing 8% soybean oil, fish oil, or coconut oil from 28 to 47 wk of age to investigate comparative effect of dietary soybean oil, fish oil, and coconut oil on the performance, egg quality and blood malondialdehyde (MDA), aspartate transaminase (AST) and uric acid (UA). Hens fed fish oil showed poor performance compared with soybean oil or coconut oil, and especially egg weight throughout the trial was significantly and consistently decreased (P < 0.05) due to dietary fish oil. Unexpectedly, shell reflectivity throughout the majority of the trial was consistently and significantly higher (P < 0.05) when hens fed fish oil than that when fed soybean oil or coconut oil. Dietary treatments affected (P < 0.05) shell shape at 4 of 8 time points tested. Average shell shape in fish oil treatment was higher (P < 0.05) than that of coconut oil group. Albumen height, Haugh unit and yolk color were influenced by dietary treatments only at 1 or 2 time points. However, average albumen height and Haugh unit in fish oil treatment were higher (P < 0.05) than that of soybean oil or coconut oil treatments and average yolk color in coconut oil treatment was higher (P < 0.05) than that of soybean oil group. Serum MDA, AST and UA concentrations were increased (P < 0.05) by fish oil during the majority of the first 2 mo of the trial. These data suggested that the inclusion of fish oil into feed may reduce the performance of laying hens, especially the egg weight, decrease the intensity of egg brown color and increase blood MDA, AST and UA levels compared with soybean oil or coconut oil. As a result, hens fed fish oil may lay smaller, longer and lighter-brown eggs whereas those fed coconut oil produce blunter and darker-brown eggs relative to soybean oil.


Asunto(s)
Pollos/fisiología , Aceite de Coco/metabolismo , Aceites de Pescado/metabolismo , Óvulo/efectos de los fármacos , Reproducción/efectos de los fármacos , Aceite de Soja/metabolismo , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales/efectos de los fármacos , Animales , Aspartato Aminotransferasas/sangre , Proteínas Aviares/sangre , Pollos/sangre , Aceite de Coco/administración & dosificación , Dieta/veterinaria , Femenino , Aceites de Pescado/administración & dosificación , Malondialdehído/sangre , Óvulo/fisiología , Aceite de Soja/administración & dosificación , Ácido Úrico/sangre
3.
Poult Sci ; 96(5): 1280-1289, 2017 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-27789747

RESUMEN

This study evaluated the effects of long-term Bacillus subtilis CGMCC 1.921 supplementation on the performance, egg quality, and fecal/cecal microbiota of laying hens. A total of 360 28-week-old Hy-Line Brown laying hens were randomly allocated into 5 treatments with 6 replicates of 12 birds each for 24 weeks. The experimental treatments included a basal diet without additions (Con) and the basal diet supplemented with 1.0 × 105 (B1), 1.0 × 106 (B2), 1.0 × 107 (B3), and 1.0 × 108 (B4) cfu/g B. subtilis CGMCC 1.921. The results showed that feed:egg ratio significantly decreased (P < 0.05) in groups B1 (wk 13 to 16, 17 to 20, 21 to 24, and one to 24), B2 (wk 13 to 16, 17 to 20, and 21 to 24), B3 (wk 13 to 16, 17 to 20, 21 to 24, and one to 24), and B4 (wk 13 to 16, 17 to 20, 21 to 24, and one to 24). However, egg production, egg weight, and feed intake were not significantly different (P > 0.05) among treatments. Eggshell strength significantly improved (P < 0.05) in groups B1 (wk 8, 16, 20, and 24), B2 (wk 20 and 24), and B3 (wk 8, 16, 20, and 24). Fecal E. coli counts significantly decreased (P < 0.05) in groups B1 (wk 16), B2 (wk 12, 16, 20, and 24), B3 (wk 12, 20, and 24), and B4 (wk 16, 20, and 24). Lactobacillus in cecal digesta of groups B1, B3, and B4 increased significantly (P < 0.01). Bifidobacterium in cecal digesta of groups B1, B2, B3, and B4 increased significantly (P < 0.05). Bifidobacterium counts increased linearly (P = 0.015) and quadratically (P = 0.004) as B. subtilis CGMCC 1.921 supplementation increased. Compared with Con, E. coli in the cecal digesta of groups B2 and B4 decreased significantly (P < 0.01). C. perfringens in the cecal digesta of groups B3 and B4 decreased significantly (P < 0.05). E. coli:Lactobacillus ratio decreased in group B1 (P < 0.05) and B2, B3, and B4 (P < 0.01). Therefore, the probiotic B. subtilis CGMCC 1.921 effectively improved performance and egg quality via the reduction of fecal E. coli and beneficial modulation of cecal microbiota.


Asunto(s)
Alimentación Animal/análisis , Bacillus subtilis , Ciego/microbiología , Pollos/microbiología , Dieta/veterinaria , Suplementos Dietéticos , Heces/microbiología , Probióticos , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Pollos/fisiología , Cáscara de Huevo , Huevos/normas , Femenino , Oviposición
4.
Poult Sci ; 94(5): 965-75, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25717085

RESUMEN

The aim of this study was to compare the effect of DL-selenomethionine (SM) with 2 routinely used Se sources, sodium selenite (SS) and seleno-yeast (SY), on relative bioavailability based on antioxidant activity and tissue Se content. Six hundred thirty 131-day-old brown laying hens were randomly assigned to 7 treatments for 168 d (24 wks) with 6 replicates of 15 hens per replicate. The SS and SY animals were supplemented a cornmeal and soybean diet that supplied a total Se 0.3 mg/kg whereas SM was added at 4 different levels to the total Se at 0.1, 0.3, 0.5 and 0.7 mg/kg. All hens fed the Se-supplemented diet showed higher glutathione peroxidase (GSH-Px) activity (P < 0.01), higher superoxide dismutase (SOD) activity (P < 0.05), lower malondialdehyde (MDA) content (P < 0.05) in plasma, and greater Se contents in egg yolks, albumen, leg muscle, breast muscle, liver, and plasma compared with those fed the control diet (P < 0.01). The organic sources (SY and SM) exhibited a greater ability to increase the GSH-Px activity (P < 0.01) and Se content in albumen (P < 0.01), leg, and breast muscles (P = 0.0099 and P = 0.0014, respectively) than the SS that was added at 0.3 mg Se/kg. The higher SM added levels increased the GSH-Px activity until the dose of 0.5mg Se/kg (P < 0.01).The greater Se concentrations in albumen, muscle and liver appeared in the higher SM-added level, as well as above the dose of 0.1 mg Se/kg (P < 0.01). In addition, hens fed the diet with SM accumulated more Se in albumen, leg, and breast muscle than those fed diets with SY (P < 0.05). These results confirmed the higher ability of organic Se sources to increase the antioxidant activity and Se deposition in egg albumen, leg, and breast muscles compared with SS, and demonstrated a significantly better efficiency of SM compared with SY for albumen and muscle Se enrichment.


Asunto(s)
Pollos/metabolismo , Selenio/farmacología , Selenometionina/farmacología , Selenito de Sodio/farmacología , Albúminas/química , Animales , Yema de Huevo/química , Femenino , Glutatión Peroxidasa/metabolismo , Hígado/química , Hígado/metabolismo , Malondialdehído/metabolismo , Músculo Esquelético/química , Músculo Esquelético/metabolismo , Selenio/sangre , Selenio/química , Selenio/metabolismo , Selenometionina/administración & dosificación , Selenito de Sodio/administración & dosificación , Superóxido Dismutasa/metabolismo , Levaduras/química
5.
Poult Sci ; 92(7): 1824-9, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23776270

RESUMEN

A total of five hundred forty 19-wk-old HyLine Brown hens were used to study the long-term effects of increasing choline with 0 (control), 425, 850, 1,700, 3,400, and 6,800 mg/kg of corn-soybean meal-based diets on productive performance and egg quality. Phase 1 was from 19 to 58 wk, and phase 2 was from 59 to 68 wk. During the whole experimental period, dietary choline had no significant effects on feed intake, egg weight, and egg mass (P > 0.05). During phase 1, egg production decreased linearly (P < 0.05) and feed conversion ratio (FCR) tended to increase linearly (P = 0.057) with increasing choline level in the diet. Moreover, BW decreased both linearly (P < 0.01) and quadratically (P < 0.05) as choline increased from 0 to 6,800 mg/kg. No significant treatment effects were found for shell thickness and shell strength of eggs (P > 0.05). However, albumen height and Haugh units increased linearly (P < 0.01 and P < 0.05, respectively) as choline increased during phase 2. Compared with the control group, diets supplemented with 425 or 850 mg of choline/kg significantly (P < 0.01) improved yolk color during phase 1. This study indicates that a dietary choline level of no more than 700 mg/kg is sufficient to maintain egg production. The effect of choline on egg quality was minimal when hens were fed a corn-soybean meal-based diet from 19 to 68 wk of age.


Asunto(s)
Pollos , Colina/farmacología , Huevos/normas , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Colina/administración & dosificación , Dieta/veterinaria , Esquema de Medicación , Femenino , Pigmentos Biológicos
6.
Poult Sci ; 91(5): 1135-41, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22499871

RESUMEN

This study was conducted to determine the influence of vitamin E on the retinol binding protein (RBP) and cytochrome p450 family 26 subfamily A polypeptide 1 (CYP26A1), which are specific transporters and catabolic enzymes of vitamin A, respectively. In the in vivo experiments, a total of 450 laying hens was fed 5 levels of vitamin E (0, 20, 80, 320, and 1,280 IU/kg of feed) supplementation. For the in vitro assays, hepatocytes from laying hens were cultured in 4 levels of α-tocopherol (0, 10, 50, and 100 µM). High dietary vitamin E increased the concentration of vitamin A in liver (P < 0.05). The RBP and its mRNA expression in liver and hepatocytes were markedly inhibited by dietary vitamin E (320 and 1,280 IU/kg) and α-tocopherol (100 µM) in culture medium (P < 0.05). However, CYP26A1 and its mRNA expression were not affected by vitamin E in both liver and hepatocytes (P > 0.05). The results indicate that excessive vitamin E could increase the concentration of vitamin A in liver by inhibiting RBP synthesis in hepatocytes.


Asunto(s)
Pollos/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Proteínas de Unión al Retinol/metabolismo , alfa-Tocoferol/farmacología , Animales , Células Cultivadas , Sistema Enzimático del Citocromo P-450/genética , Suplementos Dietéticos , Femenino , Regulación de la Expresión Génica/fisiología , Insulina/metabolismo , Hígado/citología , Oviposición/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ácido Retinoico 4-Hidroxilasa , Vitaminas/administración & dosificación , Vitaminas/farmacología , alfa-Tocoferol/administración & dosificación
7.
J Anim Physiol Anim Nutr (Berl) ; 96(1): 85-94, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21276087

RESUMEN

The present study was conducted to evaluate the effect of an aqueous alfalfa extract (AAE) on production performance, egg quality and lipid metabolism of laying hens between 28 and 36 weeks of age. Four groups of commercial hens (Hy-Line Brown) were fed with diets containing 0, 0.05%, 0.1% and 0.15% AAE. Dietary AAE had no effect on egg production parameters (p > 0.05). Shell strength was increased (linear and quadratic effects; p < 0.05) with gradient addition of AAE. Furthermore, shell strength was notably higher (p < 0.05) in 0.1% and 0.15% AAE groups than the control group. With an exception of serum low and high density lipoprotein cholesterol, serum total triglycerides and liver cholesterol concentration (day 42), lipid indices in yolk, serum and liver were lowered (linear and quadratic effects; p < 0.05) at day 42 and day 56 as AAE in diets increased, as well as the enzyme activities of acetyl-CoA carboxylase (ACC) and ß-hydroxy-ß-methylglutaryl-CoA (HMG-CoA) reductase. In relation to the control group, cholesterol and triglycerides in yolk, liver and serum and serum very low density lipoprotein cholesterol were lower in 0.15% AAE-treated birds at day 42 and day 56. It also significantly decreased activities of ACC, HMG-CoA reductase and fatty acid synthetase (FAS) at day 56. The 0.1% AAE decreased triglycerides in yolk, liver and serum, as well as the activities of ACC and FAS at day 56. These data suggest that dietary AAE could be applied to improve egg shell quality and modify the lipid status of laying hens and eggs.


Asunto(s)
Pollos , Huevos/normas , Metabolismo de los Lípidos/efectos de los fármacos , Medicago sativa/química , Oviposición/efectos de los fármacos , Extractos Vegetales/farmacología , Animales , Femenino , Flavonoides/química , Flavonoides/farmacología , Lípidos/sangre , Lípidos/química , Hígado/anatomía & histología , Hígado/química , Hígado/efectos de los fármacos , Tamaño de los Órganos , Extractos Vegetales/química , Polisacáridos/química , Polisacáridos/farmacología , Saponinas/química , Saponinas/farmacología
8.
Br Poult Sci ; 52(3): 302-9, 2011 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-21732875

RESUMEN

1. A total of 360 1-d-old male commercial Arbor Acre broiler chickens were randomly assigned to 5 groups (6 replicates of 12 birds each) to evaluate the dietary effects of polysavone (0·5, 1·0 and 1·5 g/kg), a natural extract from alfalfa, and 0·15 g/kg chlortetracycline (CTC) on growth performance, antioxidation and meat quality of broiler chickens. 2. Over the 6-week study, feed intake increased significantly with CTC supplementation and final body weight (BW) was significantly higher for 1·0 g/kg polysavone and 0·15 g/kg CTC treatments. Feed:gain ratio was not significantly affected by the dietary treatments. 3. At 3 weeks of age, serum total superoxide dismutase (T-SOD) activity for all polysavone treatments was significantly higher than controls, liver T-SOD activity in 1·5 g/kg polysavone group was significantly higher than the control and CTC groups, and serum glutathione peroxidase (GSHPx) activity for 1·5 g/kg polysavone and liver GSHPx activity in all polysavone groups were significantly higher than CTC. 4. At 6 weeks of age, serum and liver T-SOD activity in 1·5 g/kg polysavone group and liver GSHPx activity for all polysavone treatments were higher significantly than the control and CTC groups, and serum malondialdehyde (MDA) content for all polysavone treatments was significantly lower than CTC. 5. Breast muscle T-SOD activity and pH value at 6 weeks of age were significantly higher and MDA content was significantly lower in 1·0 and 1·5 g/kg polysavone groups than in the control and CTC groups. Breast muscle shear force was significantly lower in l·5 g/kg polysavone group compared with the control, and drip loss for all polysavone treatments was significantly lower than CTC. 6. It was indicated that polysavone modulates antioxidation and modifies meat quality, but with no adverse effect on performance of broiler chickens, and that CTC can be beneficial to performance but has no beneficial effect on antioxidant function or meat quality.


Asunto(s)
Antioxidantes/análisis , Pollos/fisiología , Clortetraciclina/farmacología , Carne/normas , Medicago sativa/química , Alimentación Animal/análisis , Crianza de Animales Domésticos/métodos , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Antioxidantes/metabolismo , Pollos/crecimiento & desarrollo , Dieta/veterinaria , Suplementos Dietéticos/análisis , Glutatión Peroxidasa/análisis , Glutatión Peroxidasa/sangre , Masculino , Malondialdehído/análisis , Malondialdehído/sangre , Distribución Aleatoria , Superóxido Dismutasa/análisis , Superóxido Dismutasa/sangre
9.
Bioresour Technol ; 101(11): 4125-31, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20144543

RESUMEN

A novel phytase was isolated from Aspergillus ficuum NTG-23 with a procedure involving ion-exchange chromatography on DEAE-cellulose, CM-cellulose and FPLC-gel filtration on Superdex 75. The protein exhibited a molecular mass of 65.5kDa in gel filtration and SDS-PAGE. It possessed an optimal pH of 1.3 and an optimal temperature of 67 degrees C, and manifested a K(m) of 0.295mM and a V(max) of 55.9nmol (phosphate)/min. Phytase activity was not significantly affected by metal ions such as Ca(2+), Mg(2+), Mn(2+), Zn(2+), but was slightly stimulated in the presence of EDTA. The phytase was stable at 60 degrees C with no obvious loss of activity upon its incubation at 70 degrees C for 20min. The enzyme exhibited a broad substrate selectivity and showed strong resistance toward pepsin and trypsin. The unique properties suggest that the phytase has the potential to be useful as an animal feed supplement.


Asunto(s)
6-Fitasa/genética , Aspergillus/enzimología , 6-Fitasa/química , 6-Fitasa/aislamiento & purificación , 6-Fitasa/metabolismo , Secuencia de Aminoácidos , Secuencia de Bases , Cromatografía en Gel , Clonación Molecular , Cartilla de ADN , Electroforesis en Gel de Poliacrilamida , Estabilidad de Enzimas , Concentración de Iones de Hidrógeno , Hidrólisis , Cinética , Datos de Secuencia Molecular , Peso Molecular , Reacción en Cadena de la Polimerasa , Homología de Secuencia de Aminoácido , Especificidad por Sustrato
10.
Poult Sci ; 88(7): 1394-8, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19531709

RESUMEN

The effect of dietary taurine was investigated on performance and immune responses in growing (1 to 42 d) Japanese quail. One-day-old quails of both sexes (300) were randomly allotted to 12 groups with 25 quails in each group (3 dietary treatments, 4 replicates). They were fed with maize-soybean meal-based diets containing 0, 0.01, or 0.05% taurine for 42 d. Dietary 0.01% taurine decreased food intake (P < 0.05) in the starter phase but did not affect BW gain and feed efficiency from d 1 to 42 of age. In the starter phase, dietary 0.05% taurine did not affect food intake but increased weight gain and improved feed efficiency (P < 0.05). In the grower phase, dietary 0.05% taurine did not affect weight gain but improved feed efficiency and decreased food intake (P < 0.05). In the overall period, dietary 0.05% taurine improved feed efficiency and decreased food intake (P < 0.05). The relative weights of thymus were greater in the quails given 0.01% taurine in diet (P < 0.05). The relative weights of the bursa of Fabricius and thymus were greater in dietary 0.05% taurine compared with the control (P < 0.05).The quail serum anti-Newcastle disease virus hemagglutination antibody titer in the taurine-supplemented diet had no significant effects compared with the control (P > 0.05). The response to phytohemagglutinin measured as the foot web index was significantly increased by 0.05% taurine supplementation (P < 0.05). It is concluded that the taurine-supplemented diet has a beneficial effect on immune responses and performance in growing Japanese quail.


Asunto(s)
Coturnix/crecimiento & desarrollo , Coturnix/inmunología , Dieta/veterinaria , Taurina/farmacología , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Anticuerpos/sangre , Suplementos Dietéticos , Femenino , Hemaglutininas/inmunología , Hígado/anatomía & histología , Tejido Linfoide/anatomía & histología , Masculino , Técnicas de Cultivo de Órganos
11.
Poult Sci ; 86(9): 1955-9, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17704384

RESUMEN

Two hundred 1-day-old male commercial Arbor Acres broiler birds were randomly distributed to a control group and a polysavone group (5 replicates of 20 birds each) to investigate the influence of polysavone, a natural extract from alfalfa, on abdominal fat deposition and immunity in broiler chickens. Birds in the control group were supplied with a basal diet, and 0.06% polysavone was added to the basal diet of birds in the polysavone group. Body weight and feed consumption for each replicate were recorded weekly. At 3, 4, 5, and 6 wk of age, 4 birds from each replicate were randomly selected for blood and organ sampling. Polysavone had no significant effect on feed intake, BW, or feed:gain ratio in the experimental period, and it decreased the abdominal fat weights at 5 and 6 wk of age. Polysavone improved (P <0.05) the relative thymus and spleen weights at 6 wk of age and the bursa weights at 4 and 5 wk of age compared with the control group. At 4 and 6 wk of age, the proliferation of T and B lymphocytes in the polysavone group was significantly greater (P <0.05) than that in the control group. When birds were 4 and 5 wk of age, polysavone resulted in a significant increase (P <0.05) in serum anti-Newcastle disease virus hemagglutination inhibition antibody titer. These results showed that polysavone may decrease abdominal fat deposition and enhance immunity without an adverse effect on the performance of broiler chickens.


Asunto(s)
Distribución de la Grasa Corporal/veterinaria , Pollos/inmunología , Pollos/metabolismo , Medicago sativa/química , Extractos Vegetales/farmacología , Animales , Bolsa de Fabricio/anatomía & histología , Bolsa de Fabricio/efectos de los fármacos , Proliferación Celular , Linfocitos/efectos de los fármacos , Masculino , Tamaño de los Órganos/efectos de los fármacos , Extractos Vegetales/química , Bazo/anatomía & histología , Bazo/efectos de los fármacos , Timo/anatomía & histología , Timo/efectos de los fármacos
12.
Proc Natl Acad Sci U S A ; 89(3): 895-9, 1992 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-1371011

RESUMEN

Within the nucleus, pre-mRNA molecules are complexed with a set of proteins to form heterogeneous nuclear ribonucleoprotein complexes. A1, an abundant RNA binding protein present in these complexes, has been shown to bind selectively to single-stranded RNAs and destabilize base-pairing interactions. In this study.A1 is shown to promote the rate of annealing of complementary RNA strands greater than 300-fold under a wide range of salt concentration and temperature. Maximal annealing is observed under saturating or near saturating concentrations of protein, but annealing decreases sharply at both higher and lower concentrations of A1. Kinetic analysis shows that the rate of annealing is not strictly first or second order with respect to RNA at a ratio of protein/RNA that gives optimal rates of annealing. This result suggests that A1 protein may affect more than one step in the annealing reaction. Two polypeptides representing different domains of A1 were also examined for annealing activity. UP1, a proteolytic fragment that represents the N-terminal two-thirds of A1, displays very limited annealing activity. In contrast, a peptide consisting of 48 amino acid residues from the glycine-rich C-terminal region promotes annealing at a rate almost one-quarter that observed with intact A1. The RNA.RNA annealing activity of A1 may play a role in pre-mRNA splicing and other aspects of nuclear mRNA metabolism.


Asunto(s)
Ribonucleoproteína Heterogénea-Nuclear Grupo A-B , Hibridación de Ácido Nucleico , ARN/química , Ribonucleoproteínas/fisiología , Ribonucleoproteína Nuclear Heterogénea A1 , Ribonucleoproteínas Nucleares Heterogéneas , Cinética , Cloruro de Magnesio/química , Péptidos/química , Cloruro de Sodio/química , Relación Estructura-Actividad , Temperatura
13.
J Hum Hypertens ; 4(2): 149-50, 1990 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-2338687

RESUMEN

This study shows that nimodipine significantly reduces levels of blood pressure in patients with mild and moderate essential hypertension. Hypotensive efficacy is less than with nifedipine, but side effects are light, and the drug is shown to reduce serum Na+ and cholesterol and there is regression of LVH (ECG).


Asunto(s)
Hipertensión/tratamiento farmacológico , Nimodipina/uso terapéutico , Adulto , Anciano , Humanos , Persona de Mediana Edad
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