The Molecular Effects of BDNF Synthesis on Skeletal Muscle: A Mini-Review.

The brain-derived neurotrophic factor (BDNF) is a member of the nerve growth factor family which is generated mainly by the brain. Its main role involve synaptic modulation, neurogenesis, neuron survival, immune regulation, myocardial contraction, and angiogenesis in the brain. Together with the encephalon, some peripheral tissues synthesize BDNF like skeletal muscle. On this tissue, this neurotrophin participates on cellular mechanisms related to muscle function maintenance and plasticity as reported on recent scientific works. Moreover, during exercise stimuli the BDNF contributes directly to strengthening neuromuscular junctions, muscle regeneration, insulin-regulated glucose uptake and ß-oxidation processes in muscle tissue. Given its vital relevance on many physiological mechanisms, the current mini-review focuses on discussing up-to-date knowledge about BDNF production in skeletal muscle and how this neurotrophin impacts skeletal muscle biology.

[Effects of carvedilol in rats with induced chronic kidney failure]. / Efectos del carvedilol en ratas con insuficiencia renal crónica inducida.

Hypertensive mechanisms are postulated to play a major role in the progressive glomerulosclerosis (GS) after renal mass reduction. Previous studies have demonstrated differences in the progression to glomerulosclerosis with the use of different antihypertensive drugs. We analyzed whether the use of carvedilol (CVD), a new beta-adrenoceptor antagonist and vasodilator slows the progression of glomerulosclerosis in 5/6 nephrectomised (Nx) rats. Fifty-four adult Sprague-Dawley rats were distributed among five groups, four with 5/6 Nx, vehicle treated and CVD at 5, 10 and 20 mg/kg/day and sham (no renal ablation or drug treatment). Tailcuff blood pressure, serum creatinine and urine protein concentration were measured. At the end of the experiment remnant kidney was removed for morphometric studies. Rats treated with 10 and 20 mg/kg/day of CVD showed controlled systemic blood pressure. Serum creatinine was similar in all treated groups with CVD, and half the levels observed in the vehicle-treated rats. The prevalence of glomerular lesions was closely associated with the degree of proteinuria. Eleven weeks after 5/6 Nx, vehicle-treated rats exhibited marked GS with 76% of affected glomeruli and creatinine retention. By contrast, renal injury was largely prevent in those rats treated with 10 and 20 mg/kg/day of CVD. Tuft enlargement occurred in all groups but was more prominent in vehicle-treated group, 1.5 times higher than the group treated with 20 mg/kg/day of CVD. Although, these data demonstrate the importance of systemic blood pressure control in the renal protective efficacy of carvedilol, other less-known mechanisms of this drug must be investigated.

Efectos del carvedilol en ratas con insuficiencia renal crónica inducida / Effects of carvedilol in rats with induced chronic renal failure

Se postula que los mecanismos hipertensivos juegan un papel desencadenante en la glomeruloesclerosis (GS) tras la reducción de la masa renal. Estudios previos han demostrado diferencias en la progresión hacia la glomeruloesclerosis con el uso de fármacos antihipertensivos. Analizamos si el uso de carvedilol (CVD), un nuevo antagonista de los receptores adrenérgicos beta y vasodilatador, retrasa la progresión de la glomeruloesclerosis en ratas con 5/6 de nefrectomía (Nx). Se distribuyeron cincuenta y cuatro ratas adultas Sprague-Dawley en cuatro grupos con 5/6 Nx, control y CVD a 5, 10 y 20 mg/kg/día. A estos grupos se añadió un grupo sham (sin ablación renal ni tratamiento farmacológico). Se midió la presión arterial en la cola, y la concentración sérica de creatinina y la urinaria de proteínas Los riñones remanentes se extrajeron al final del experimento para su estudio morfométricoLas ratas tratadas con 10 y 20 mg/kg/día de CVD presentaban cifras de presión arterial sistémica dentro de límites normales. Los niveles séricos de creatinina fueron similares en todos los grupos tratados con CVD, y la mitad de los observados en las ratas control. La prevalencia de las lesiones glomerulares se relacionó estrechamente con el grado de proteinuria. A las once semanas de los 5/6 Nx, las ratas control exhibieron una marcada GS con un 76 por ciento de glomérulos afectados y con elevación de la creatinina. Por el contrario, la lesion renal estuvo marcadamente atenuada en aquellas ratas tratadas con 10 y 20 mg/kg/día de CVD. La hipertrofia glomerular, salvo en el sham, ocurrió en todos los grupos, pero fue más prominente en el grupo control, 1,5 veces mayor que en el grupo tratado con 20 mg/kg/día de CVD.Aunque estos datos demuestran la importancia del control de la presión arterial sistémica en la eficacia del carvedilol como protector renal, otros mecanismos renoprotectores de este fármaco deberían er investigados. (AU)