ABSTRACT
El efecto de sobrealimentación sobre las características de la canal y la degradación de la vinculina y la troponina-T a tres tiempos postmortem (0, 24 y 48 h), fue evaluado en 10 novillos doble propósito de 21 m de edad. Los animales fueron segregados al azar en dos tratamientos durante 12 m, como sigue: Tratamiento 1 (T1): cinco (5) novillos (grupo testigo) alimentados con heno (Cynodon nlemfuensis), más 20% de concentrado (relación heno:concentrado = 80:20, para una ganancia diaria de peso (GDP) de 100 g/d). Tratamiento 2 (T2): cinco (5) novillos alimentados con heno (Cynodon nlemfuensis), más 40% de concentrado (relación heno: concentrado = 60:40, para una GDP de 500 g/d). Las canales fueron evaluadas, para las características cualitativas y cuantitativas a las 24 h postmortem. Para evaluar la degradación de vinculina y troponina-T mediante la técnica de Western Blot, se colectaron 0,5 g del músculo longissimus dorsi de cada media canal al beneficio (0, 24 y 48 h postmortem). El análisis de varianza(ANAVAR) incluyó el peso de los animales al inicio del ensayo como covariable. Los resultados indicaron que las canales de los novillos sobrealimentados mejoraron sus características en canal, presentando mayor área del ojo costal, mayor espesor de grasa y mayor madurez ósea (P<0,05), sin alcanzar niveles adecuados de acabado de grasa. Se observó que la sobrealimentación no varió el patrón de degradación de la vinculina y la troponina-T a ningún tiempo postmortem. La vinculina se degradó a partir de las 24 h postmortem; sin embargo, no se detectó degradación de la troponina-T. Estos resultados deben ser confirmados con un número mayor de animales junto con la evaluación cuantitativa de la expresión de las proteínas.
The effect of overfeeding on carcass characteristics and on degradation of vinculin and troponin-T at three different postmortem times (0, 24, and 48 h) were evaluated in dual purpose steers. A total of 10 steers, 21 months of age was used. The animals were randomly selected and allocated to two different treatment protocols for 12 months, as follows: Treatment 1 (T1): Five steers (Control Group) fed with a diet consistent of hay (Cynodon nlemfuensis) plus concentrate, with a hay/concentrate ratio of 80:20, to reach a daily weight gain (DWG) of 100 g/d; Treatment 2 (T2); five steers fed with hay (Cynodon nlemfuensis) plus concentrate with a hay/concentrate ratio of 60:40, to obtain a DWG of 500 g/d. Carcasses were assessed for both qualitative and quantitative characteristics at 24 h postmortem. To evaluate the degradation of vinculin and troponin-T at three different times (0, 24, and 48 h postmortem), 0.5 g of the longissimus dorsi muscle was collected from each half carcass and subjected to a Western blot analysis. Samples were analyzed by ANOVA. The analysis included the weight of the animals as a covariance. The results of the present investigation indicate that the carcasses of overfed steers exhibited better carcass traits, showing larger loin eye areas, back fat thickness, and a skeletal maturity (P≤0.05), without reaching adequate levels of fat finish. It was also observed that overfeeding did not change the pattern of degradation of vinculin and troponin-T at any postmortem time. Vinculin showed degradation at 24 h postmortem while troponin-T was not degraded. These results must be confirmed using a greater number of animals and a quantitative evaluation of protein expression.
ABSTRACT
An arrangement of subscapularis muscle fibres was investigated in 33 male and 15 female Thai cadavers. The muscle was a sheet showing multipennate arrangement. It consisted of upper pinnate fasciculi interdigitating with lower pinnate fasciculi. Each upper and lower pennate fasciculus had ascending and descending intramuscular tendinous septum in the middle respectively. In addition, some descending tendinous septa bifurcated and the lower pennate fasciculus were subdivided into pair pennate fasciculi. New discovery of the bifurcation of some asconding septa and the upper pair pennate fasciculi was recorded.
ABSTRACT
Whether or not muscle hypertrophy induced by physical exercise will result in the increase in thenumber of muscle fibres is a question much debated in recent years. But little has been done so farin studying the effect of short and long term weight training on the changes in the number of muscle fibres in the human body. As an attempt to find out this effect, a research has been madeon 29 male subjects. Nine young trainees at spare-time sports schools were put through a weightliftingprogramme consisting of three hours of work a day, six days a week for 10 weeks. Before and afterthe 10-week period, the cross section of the musculus vastus lateralis was measured with computedtomography scanning (CT); maximal voluntary isometric torques of knee extension were alsomeasured; muscle biopsies were taken from the vastus lateralis to distinguish between muscle fibresof type I and type II and to find out their distribution and their average areas; and the number ofmuscle fibres was calculated by a formula. The results were compared with those obtained from thecontrol group of 13 persons and a group of seven weightlifters of national ranking. It was found thatthe 10 weeks of weight training did not result in the increase in the number of muscle fibres althoughit caused some change in the maximal torque; and that although long-term training resulted insignificant changes in the maximal torque and the area of muscle fibres, there was no significantdifference in the number of muscle fibres between the elite group on the one hand and the controlgroup and the group of trainees who had gone through 10 weeks of training on the other. Thesefindings supported Soviet scholars' idea that to respond to load stress, animals depend on bothhypertrophy and hyperplasia in the muscle while man relies on hypertrophy alone. They alsosuggested the need for further studies on this subject.