Succinic Dehydrogenase and Cholinesterase Activities in the Skeletal Muscles of the Desert Rat and the Albino Rat

Abstract

The deltoid and gluteus maximus of the desert rat and the albino rat were examined histochemically for the distribution of succinic dehydrogenase (SDH) and cholinesterase (ChE). SDH activity showed that the deltoid and gluteus maximus muscles of the two animals consisted of three types of muscle fibres, with a predominance of muscle fibres that have higher SDH activity in both the deltoid and gluteus maximus muscles of the desert rat than in the albino rat. The mean diameter of all muscle fibres in the deltoid and gluteus maximus muscles and their ratios to the average body weight were determined in both animals. The desert rat showed a statistically significant increase in those ratios compared with the corresponding ratios for the albino rat. ChE activity showed that the deltoid and gluteus maximus muscles are richly innervated by intensely positive ChE motor end-plates with a predominance of plaque-like terminals. The mean diameters of the end-plates and the ratios of these diameters to the diameter of the muscle fibres together with their ratios to the body weight were determined. A correlation between these values and the histological findings is proposed.

Protein-Energy Malnutrition Causes Deficits in Motor Function in Adult Male Rats

“…During bar hanging, the NP rats more often used a grip around the bar between digits and palm to initiate a ''straight-arm hang.'' This movement uses multiple sets of muscles, including flexor digitorum superficialis and flexor digitorum profundus in the paw (47,48), wrist flexors, brachioradialis and extensor carpi radialis muscles in the forearms, and deltoid (49) and spino-and clavo-trapezius (50) muscles in the shoulders. Forelimb muscle dysfunction in LP rats was identified by increased use of an adaptive bar-hanging strategy in which the rats used more ''flex-arm hangs'' (pull-ups) intermittently with ''straight-arm hangs.''…”