ABSTRACT
A general analysis of the behaviour of "Cebus" shows that when this primate moves position to feed or perform another activity, it presents different ways of locomotion. This information shows that the brachial biceps muscle of this animal is frequently used in their locomotion activities, but it should also be remembered that this muscle is also used for other development activities like hiding, searching for objects, searching out in the woods, and digging in the soil. Considering the above, it was decided to research the histoenzimologic characteristics of the brachial biceps muscle to observe whether it is better adpted to postural or phasic function. To that end, samples were taken from the superficial and deep regions, the inserts proximal (medial and lateral) and distal brachial biceps six capuchin monkeys male and adult, which were subjected to the reactions of m-ATPase, NADH-Tr. Based on the results of these reactions fibres were classified as in Fast Twitch Glycolitic (FG), Fast Twitch Oxidative Glycolitic (FOG) and Slow Twitc (SO). In general, the results, considering the muscle as a whole, show a trend of frequency FOG> FG> SO. The data on the frequency were studied on three superficial regions FOG=FG>SO; the deep regions of the inserts proximal FOG=FG=SO and inserting the distal FOG>FG=SO. In conclusion, the biceps brachii of the capuchin monkey is well adapted for both postural and phasic activities.
Subject(s)
Arm/physiology , Cebus/metabolism , Muscle Fibers, Skeletal/enzymology , Animals , Arm/innervation , Cebus/classification , Cebus/physiology , Histocytochemistry , Locomotion , Male , Muscle Fibers, Fast-Twitch/enzymology , Muscle Fibers, Fast-Twitch/physiology , Muscle Fibers, Skeletal/physiology , Muscle Fibers, Slow-Twitch/enzymology , Muscle Fibers, Slow-Twitch/physiologyABSTRACT
The phylogenetic proximity of primates to humans, along with their behavioral, biochemical, and anatomical similarities, make such animals more interesting experimental models for biomedical researches, as compared to classical laboratory animals. Another aspect that has called the attention of researchers is the differentiated quadrupedalism present in some primates. The tufted capuchin monkey uses the ground and tree branches as its support for locomotion, showing various postures while performing this task. On the basis of this information, we have decided to study the rectus abdominis muscle of the tufted capuchin monkey, with the following goals: the frequency and area of fiber types; its possible compartmentalization; and identify if this muscle is better adapted to phasic or postural activities. To do this, samples were removed from 4 regions of the rectus abdominis muscle of 6 adult male tufted capuchin monkeys, and were submitted to reaction with m-ATPase, (with alkaline and acid pre-incubation), NADH, and H.E.. Results showed: a statistically significant difference (P<0.05) for both frequency and area, between fiber types FG and FOG and FG and SO, but did not show a statistically significant difference between fibers FOG and SO, in all studied regions; similarity in frequency and area of a same fiber type (FG, FOG, and SO) among the studied regions. Based on these data, it was concluded that: the rectus abdominis muscle of the tufted capuchin monkey does not show fiber compartmentalization, since the distribution and size patterns of the different fiber types are similar in the studied regions; there is a predominance of fast twitch fibers (FG + FOG) over slow twitch fibers (SO), for frequency and area, which characterizes the muscle as being more dedicated to phasic than to postural activities.
La proximidad filogenética y las semejanzas de comportamiento, bioquímicos y anatómicos, de los primates con los humanos convierten a estos animales en modelos experimentales más interesantes para las investigaciones biomédicas, que los animales clásicos de laboratorio. Otro aspecto que ha llamado la atención de los investigadores es el movimiento cuádruple diferente que presentan algunos primates. El macado clavo se traslada usando como apoyo el suelo y las ramas de los árboles, presentando posturas variadas en la ejecución de esas tareas. En base a estas informaciones se resolvió estudiar el músculo recto del abdomen del macaco-clavo, con los siguientes objetivos: observar la frecuencia y el área de los tipos de fibras de este músculo; observar posibles diferencias entre e1las y sus regiones media proximal y distal; y su participación en la locomoción de este animal. Para ello, fueron retiradas 4 muestras de 4 regiones del músculo recto del abdomen, de 6 macacos-clavos machos adultos, que fueron sometidos a las reacciones de m-ATPasa (previa incubaciones alcalina y ácida), NADH y HE. Los resultados mostraron: diferencias estadísticamente significativas (p<0,05) tanto en la frecuencia como en el área, entre las fibras del tipo FG y FOG y FG y SO, pero no presentaron diferencias estadísticamente significativas entre las fibras FOG y SO, en todas las regiones estudiadas. Basándome en estos datos, se concluye que el músculo recto del abdomen del macaco-clavo no presenta división de sus fibras, pues los patrones de distribución y tamaño de los diferentes tipo de de fibras son semejantes en las regiones estudiadas con predominio de las fibras de contracción rápida (FG + FOG) sobre aquellas de contracción lenta (SO), tanto en la frecuencia como en el área, caracterizándolo como un músculo más adaptado para las actividades sutiles que posturales.
