Saddleback Journal of Biology - Saddleback College

Spring 2010 Biology 3B Paper
Literature Cited
Cornwell, R. E., Boothroyd, L., Burt, D. M.,
Feinberg, D. R., Jones, B. C., Little, A. C., Pitman,
R., Whiten, S., and Perrett, D. 2004. Concordant
preferences for opposite-sex signals? Human
pheromones and facial characteristics. The Royal
Society.
Gangestad, S. and Thornhill, R. 1998. Menstrual
cycle variation in women’s preferences for the scent
of symmetrical men. The Royal Society.
Regan, P. C. 1996. Rhythms of desire: the association
between menstrual cycle phases and female sexual
desire. Department of psychology, California State
University Los Angeles, California.
Rhodes, G., Proffitt, F., Grady, J., and Sumich, A.,
1998. Facial symmetry and the perception of beauty.
Psychonomic society, inc.
Rikowski, A. and G., Karl 1999. Human Body odour,
symmetry and attractiveness. The Royal Society.
The Effect of an Injected Glutamine Load on Time to Exhaustion in Western Fence Lizards
(Sceloporus occidentalis)
Ryan M. Palhidai and Chelsea E. Santos
Department of Biological Sciences
Saddleback College
Mission Viejo, California 92692
Glutamine is the most abundant amino acid in the human body. It is often
advertised as a nutritional supplement used to increase lactate threshold prior to exercise.
Lizards are prime candidates for this study because of their short time to reach exhaustion.
While lactate accumulates in the muscles and blood of lizards, muscular function
significantly declines. It was predicted that an injection of glutamine will prolong the
exhaustion caused by lactate accumulation in Sceloporus occidentalis. The mean weight
specific time to reach exhaustion for the lizards after receiving no injection was 16.85 ±
1.48 sec•g -1 (± S.E.M, n=11). For the other three trials, the lizards were injected with a
glutamine solution at a dosage of 2.5 g•kg -1 which was adjusted to 300 mOSM using NaCl.
The amino acid was allowed to metabolize for a specific amount of time, ten, twenty, or
thirty minutes. The mean mass specific times to reach exhaustion were 16.59 ± 0.91 sec•g -1 ,
23.60 ± 1.07 sec•g -1 , and 19.25 ± 0.96 sec•g -1 , (± S.E.M., n=11) respectively. An injected
glutamine load significantly prolonged exhaustion (p= 0.0042, repeated-measure ANOVA,
n=11).
Introduction
Common literature has noted that glutamine,
the most abundant amino acid in the human body,
can be consumed as a nutritional supplement to
increase lactate threshold prior to exercise. Further
research on the topic has shown that glutamine works
by increasing the concentration of plasma
bicarbonate (Welbourne, 1995). Bicarbonate is
produced as a by-product when glutamine is
metabolized in the proximal tubules of the kidney,
especially during times of acidosis. Acidosis is a
decrease in plasma pH. Bicarbonate acts as a well
known buffer system, which buffers lactic acid in the
muscles and blood. It has been shown that sodium
bicarbonate can be taken as a supplement to delay
fatigue during a high intensity workout (McNaughton
et al., 1999). Based on this research, it stands to
reason that an injected load of glutamine will
increase bicarbonate concentrations, prolonging
lactate accumulation, and thus, increasing the time it
takes to reach exhaustion.
Lizards, particularly Sceloporus
occidentalis, are restricted in their ability to utilize
aerobic metabolism. Instead, they rely primarily upon
anaerobiosis for rapid creation of ATP in the muscles
(Bennett and Dawson, 1972). While anaerobiosis can
provide higher levels of performance, it can also lead
to a variety of metabolic consequences, some of
19
Saddleback Journal of Biology
Spring 2010