Vastus Lateralis

The sites for IM administration are the deltoid muscle (upper arm), the ventrogluteal or dorso-gluteal sites (hip), and the vastus lateralis (thigh Pig. 2-7). The vastus lateralis site is frequently used for infants and small children because it is more developed than the gluteal or deltoid sites, hi children who have been ambulating for more than 2 years the ventrogluteal site may be used. 

FIGURE 2-7. Stes for intramuscular administration. (A) Vastus lateralis site the patient is supine or sitting. 

Figure 6. Glycogen content in the vastus lateralis muscle as a function of cycling time at 75-80% of maximal oxygen uptake (VO2 max). Data points are mean values from 10 subjects. For each subject, exercise was performed repeatedly in periods of 15 min separated by 15 min rest periods. At the point of exhaustion and muscle fatigue, muscle glycogen stores were depleted. From Bergstrom and Hultman (1967) with permission from the publisher.

Figure 7. Muscle glycogen utilization rates at various exercise intensities expressed as a percentage of VO2 max. VL, vastus lateralis SOL, soleus CAST, gastrocnemius. Redrawn from Costill etal.(1971), Hermansen etal. (1967), Saltin and Karlsson (1971), and Sherman et al. (1981).

Figure 8. A. Glycogen content in the vastus lateralis muscle after a mixed diet (a) and during 5 days of total starvation ( ) in one subject and eight days of carbohydrate-poor diet (o) followed by a carbohydrate-rich diet ( ) in a second subject. B. Muscle glycogen content before and after exercise. Before exercise the diet was mixed (a) and in the following days was either total starvation ( ) or carbohydrate-poor (o) and finally followed by 1-2 days of a carbohydrate-rich diet ( ). Note the slow rate of glycogen resynthesis when the diet is carbohydrate-poor compared to the rate when the diet is carbohydrate-rich. Redrawn from Hultman and Bergstrom (1967).

Figure 10. The relationship between the initial glycogen content in vastus lateralis muscle and work time in six subjects who cycled to exhaustion at 75% VO2 max. Each subject cycled to exhaustion on three occasions. The first experiment was preceded by a mixed diet (a), the second by a carbohydrate-poor diet (o), and the third by a carbohydrate-rich diet ( ). The energy contents of the diets were identical. In all experiments depletion of the muscle glycogen store coincided with exhaustion and muscle fatigue. From Bergstrom et al. (1967) with permission from the publisher.

It is not surprising that intramuscular injection of epinephrine into the vastus lateralis produces a prompt peak plasma epinephrine concentration, because of the large size and excellent vascularization of this muscle. It is also not surprising that subcutaneous injection of epinephrine potentially leads to delayed absorption, because of the potent Ui-adrenergic agonist vasoconstrictor effects in the skin and subcutaneous tissue, as evidenced by skin blanching at the injection site [19, 20]. 

For overweight adolescents and adults, autoinjectors containing a 0.5-mg dose of epinephrine are needed however, this dose is not available in most countries. Moreover, in many overweight people, attempts to inject epinephrine intramuscularly from most currently available autoinjectors are likely doomed to failure, because the attached needle is too short to penetrate the poorly vascularized adipose tissue layer over the vastus lateralis [26]. 

Route The test article is injected into the vastus lateralis of each rabbit. 

Volume M. vastus lateralis and cervicodorsal subcutis 1.0 ml per site auricular vein 0.5 ml per site. 

A muscle consists of groups of muscle bundles that join into a tendon at each end. The muscle bundles in the quadriceps are the vastus medialis, rectus femoris, vastus inter-medialis and vastus lateralis. Each bundle is separately wrapped in a sheath of connective tissue. Each muscle is composed of many fibres, packaged into bundles of about... 

Figure 13.4 Electron micrographs of the different fibres in different athletes. The fibre composition (type I and type II) of two selected top athletes, (a) A swimmer, whose speciality is the 50 metre crawl sprint, (b) A professional world-class cyclist of the roller type, (c) and (d) Cryostat sections of the swimmer s and cyclist s vastus lateralis stained for myosin ATPase, after preincubation at pH 4.3. Type I fibres stain dark, type II fibres remain unstained, (c) Almost all of the swimmer s fibres are type II. (d) Almost all of the cyclist s fibres are type I. Photographs kindly provided by Professor Hans Hoppeler, Department of Anatomy, University of Bern, Switzerland. Published in Strength and Power in Sport, ed. P.V. Komi, Blackwell Science (1992), pp.39-63.

Figure 13.23 Depletion of muscle glycogen content during prolonged physical activity. The units of glycogen are xmoLs glucose-equivalent per gram fresh muscle. Glycogen content was measured in biopsy samples taken from the vastus lateralis muscle. Exhaustive physical activity was performed on a bicycle ergometer. Exhaustion coincided with the glycogen content when it was close to zero. (Data from Hermansen et ai, 1967).

These compounds are measured in biopsy samples of muscle (vastus lateralis). 

Harris, R. C., Tallon, M. J., Dunnett, M., Boobis, L., Coakley, J., Kim, H. J., Fallowfield, J. L., Hill, C. A., and Wise, J. A. (2006). The absorption of orally supplied beta-alanine and its effects on muscle carnosine synthesis in human vastus lateralis. Amino Acids 30, 279-289. 

J. J. Brault, T. F. Towse, J. M. Slade and R. A. Meyer, Parallel increases in phosphocrea-tine and total creatine in human vastus lateralis muscle during creatine supplementation. Int. J. Sport Nutr. Exerc. Metab., 2007,17,624-634. 

Figure 6-4 Phosphorus-31 NMR spectrum of an excised rat muscle (vastus lateralis) in Ringer solution at 15°C. The spectrum represents the accumulation of 400 scans. From P. J. Seeley et al.64...

A considerable amount of fundamental physiological research on striated muscle has been done with the aid of calorimetiy in the last 80 years but, only recently has the heat dissipation in human tissue been used as an indicator of clinical conditions. Monti s group has successfully developed a microcalorimetric technique for studying the metabolic activity of biopsies from the vastus lateralis... 

The test is preferably conducted by injections into the M. sacrospialis on the dorsum or into the M. vastus lateralis on the femur of the rabbits. Alternatively, in the rat the injections can be performed into the M. quadriceps femoris. Also dogs could be used, however for animal wellfare reasons, smaller animals are preferred. Injection of the vehicle is performed on the contra-lateral side of the animal. The injection volume should be 1 ml for smaller animals and 2 ml for the dog. 

Figure 3. The Influence of exercise duration, during different intensities of treadmill running, on cytochrome c content in the white section of the vastus lateralis muscle (fast-twitch white fibers) of rats. Running speed (O ) 10 m/min, ( ) 20 m/min, ( A) 30 m/min, ( ) 40 m/min, ( ) 50 m/min, (A) 60 m/min, "Reproduced with permission from Ref. 44. Copyright 1982, American Physiological Society. "...

Absorption of i.m. administered medications depends on the injection site because perfusion of individual muscle groups differs. For example, drug absorption from the deltoid muscle is faster than that from the vastus lateralis that is more rapid than from the glu-teus. In addition, lower perfusion or hemostatic decompensation, frequently observed in ill neonates and young infants, may reduce i.m. absorption. It may also be decreased in neonates who receive a skeletal muscle-paralyzing agent such as pancuronium because of decreased muscle contraction. In addition, the smaller muscle mass of neonates and young infants provides a small absorptive area. 

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