[Repercussions of chromium picolinate in the protein metabolism based on the age]. / Repercusiones del picolinato de cromo en el metabolismo proteico en función de la edad.

ANTECEDENTS: Commercialized like dietetic supplement, chromium picolinate has been promoted to favour the increase of muscle mass and the loss of weight, due to its' effect on the action of insulin. OBJECTIVE: To evaluate the effect of supplementation of the diet with chromium (500 microg/kg) in the form of chromium picolinate (CrPic) (12 days) on growth and protein turnover in rats at different growth stages (infantile and puberal). RESULTS AND DISCUSSION: No significant effect of CrPic on bodyweight gain, feed intake and feed conversion rate was observed at any of the stages of development studied. CrPic seems to increase the muscle mass, either by stimulating protein anabolism due to the involution of the insulin by chromium, or by reducing protein catabolism. CONCLUSIONS: Since the use of chromium picolinate could jeopardize the correct renal function and its' beneficial effects are not evident, it should always be consumed with caution.

Repercusiones del picolinato de cromo en el metabolismo proteico en funcion de la edad / Repercussions of chromium picolinate in the protein metabolism based on the age

Antecedentes: Comercializado como suplemento dietético, el picolinato de cromo ha sido promocionado como constructor muscular y como un agente de pérdida de peso, al incrementar el músculo esquelético por su acción sobre la insulina. Objetivo: En este estudio se ha evaluado el efecto que, la suplementación de la dieta de ratas en distintas etapas de crecimiento (infantil y puberal), con 500 µg Cr/día en forma de picolinato de cromo (12 días), tiene sobre su crecimiento y utilización proteica. Resultados y discusión: Los resultados obtenidos indican que el picolinato de cromo no ejerce un efecto significativo sobre el crecimiento, ingesta de alimento, aprovechamiento de alimento y utilización de nutrientes, especialmente proteínas, en ninguno de los estadios de desarrollo estudiados. Asimismo, se ha comprobado la escasa repercusión de la suplementación de este compuesto sobre la masa corporal que, en cualquier caso, sería atribuible a su capacidad para disminuir el catabolismo proteico, más que a una activación de la acción de la insulina. Conclusiones: Dado que la utilización del picolinato de cromo podría comprometer el correcto funcionamiento renal y sus efectos beneficiosos no son evidentes, su consumo debería realizarse con mucha precaución (AU)

Antecedents: Commercialized like dietetic supplement, chromium picolinate has been promoted to favour the increase of muscle mass and the loss of weight, due to its' effect on the action of insulin. Objective: To evaluate the effect of supplementation of the diet with chromium (500 µg/kg) in the form of chromium picolinate (CrPic) (12 days) on growthand protein turnover in rats at different growth stages (infantile and puberal). Results and discussion: No significant effect of CrPic on bodyweight gain, feed intake and feed conversion rate was observed at any of the stages of development studied. CrPic seems to increase the muscle mass, either by stimulating protein anabolism due to the involution of the insulin by chromium, or by reducing protein catabolism. Conclusions: Since the use of chromium picolinate could jeopardize the correct renal function and its' beneficial effects are not evident, it should always be consumed with caution (AU)

Peligros y beneficios potenciales de la suplementación con picolinato de cromo a ratas en edad puberal: efecto sobre el crecimiento y metabolismo proteico / Dangers and potential benefits of the suplementation with chromium picolinate to rats in puberal age: effect on the growth and protein metabolism

El cromo, un popular pero controvertido micronutriente, puede incrementar el músculo esquelético cuando se administra en forma de suplemento, presumiblemente debido a su acción sobre la insulina. Este estudio se ha realizado con el fin de evaluar los efectos de tres niveles diferentes de cromo dietético (100, 200 y 500 µg/Kg) en forma de picolinato de cromo (Pic-Cr) sobre el crecimiento y utilización proteica de ratas en edad puberal, durante doce días. La suplementación de la dieta de estos animales no ejerce un efecto significativo sobre el crecimiento, ingesta de alimento, aprovechamiento de alimento y utilización de nutrientes, especialmente de proteínas. El efecto del PicCr sobre la masa corporal, además de no ser significativo, sería totalmente marginal y atribuible, más que a su acción sobre la activación de la insulina, a su capacidad para disminuir el catabolismo proteico. El consumo de este compuesto, además, podría comprometer el buen funcionamiento renal, por lo que debería realizarse con mucha precaución (AU)

Effect of diabetes on the tissular Zn/Cu ratio.

One of the parameters related to the development of coronary disease in diabetic patients is the tissular Zn/Cu ratio. We evaluated the levels of Zn and Cu, and the Zn/Cu ratio in insulin target tissues in diabetic and normoglucemic growing Wistar rats in order to determine the influence of diabetes and the disease evolution period. Diabetes was induced chemically by administration of streptozotocin. In order to determine the influence of the duration of diabetes on the Zn/Cu ratio, three time periods were studied: 7, 21 and 60 days. The animals were subsequently sacrificed and the target tissues (liver, adipose tissue, and skeletal muscle) were removed. Zn and Cu levels were measured by AAS after wet mineralization. STZ-induced diabetes modified the tissular Zn and Cu content. There was a significant decrease (p < 0.01) in liver and adipose tissue, but not in skeletal muscle. The in adipose tissue and skeletal muscle, but not in liver, effects were dependent on the duration of diabetes. The Cu content was higher in the liver of diabetic rats (p < 0.1) and lower in adipose tissue (p < 0.1) and skeletal muscle (NS). Tissular Cu levels also were affected significantly by the duration of diabetes. The Zn/Cu ratio showed a generalized decrease, except in skeletal muscle. This decrease was dependent on the presence of diabetes mellitus and the duration of the disease (p < 0.01).