Iatreia (Jan 2003)
Cinética de producción de H 2O2 y su efecto sobre la actividad mitocondrial en embriones bovinos producidos in vitro
Abstract
Durante la producción de embriones in vitro, una gran proporción<br />(70-80%) detiene su ciclo celular durante un período determinado<br />para cada especie coincidiendo con la activación del genoma<br />embrionario, lo cual en bovinos ocurre en el paso de 8 a 16 células<br />(1). Con el ánimo de aportar al estudio de este fenómeno, se determinaron la cinética de producción de H2O2y la función mitocondrial, aspectos relacionados con el mismo (2), en embriones bovinos producidos in vitro (EBPIV) con alto y bajo potencial de desarrollo. Influence of ad libitum intake of beverages with differente osmolarities on some physiological parameters during a high-intesnsity, long-duration physical activity OBJETIVE: To establish the influence of ad libitum intake of hydrating beverages with different osmolarities on the percentage of body weight loss (%BW), the increase of heart rate (HR), and the percentage of plasma volume decrease (%PV) in athletes during a high-intensity and long-time run. METHODOLOGY: After 9 warm-up minutes on a treadmill at a speed equivalent to 50% of the heart rate reserve, the athletes performed a run at 80% of the heart rate reserve speed, followed by 90 minutes of recovery. During the “dehydrated treatment” no fluid replacement was given, but during the “hydrated treatments” similar volumes were ad libitum drunk of each of three hydrating beverages, namely hyperosmolar (Hiper), hypoosmolar (Hipo) and isoosmolar (Iso). RESULTS: In all treatments there were increases of the percentage of body weight loss (%BW) (p< 0.001) and of the HR (p < 0.05), and there was a correlation between the %BW and the increase of HR (p < 0.000); in the DH and Hyper treatments a decrease of the percentage of plasma volume loss (%PV) (p < 0.05) was observed. An interaction treatment-time with the %WB was observed. CONCLUSIONS: Ad libitum intake of rehydrating beverages was less than the amount recommended in the international literature. That may have been the reason why the effects of osmolarity of such beverages on the analyzed parameters could not be determined. The amount of the %BW, the HR increase and the %PV decrease were proportional
