The objectives of this study were a) to determine
if pyridoxine (PN) supplementation increases the rate at
which plasma urea and ammonia return to basal levels,
following exercise, b) to determine, by open circuit
calorimetry, the utilization of carbohydrates, and c) to
further understand vitamin B-6 metabolism during and
following strenuous exercise. Six male athletes (age 26 ±
5 years and VO₂ max 66.4 ± 6.9 ml/kg/min) exercised for 1
hour on a cycle ergometer at 72% VO₂ max at two points
during a 17 day study. For the first 8 days subjects
received daily a placebo solution, while during the next
half they received a PN dose (20 mg). Subjects consumed
a constant diet the day before, day of, and day after the
exercise test. Blood samples were taken the day of the
exercise test at fasting (Fl), pre-exercise (PE), during exercise (DE), 1 min post exercise (I'P), 6 hour post
exercise (6hP), and the day after the exercise test at
fasting (F2). Plasma was analyzed for ammonia, urea, and
pyridoxal 5'-phosphate (PLP). ANOVA showed no
significant difference between treatments for either
plasma ammonia or urea. While there was a significant
increase (p<0.001) in plasma ammonia levels over time
with the placebo, with supplementation the increase over
time was not significant. With PN supplementation,
plasma PLP levels were significantly correlated (p<0.05)
with plasma ammonia levels at I'P. A slight decrease in
plasma urea concentration was observed with the PN
treatment at PE, DE, I'P, and 6hP. It was concluded
that PN may reduce adverse consequences of plasma
ammonia and urea seen with exercise. On the other hand,
pyridoxine supplementation may produced a shift in the
utilization of substrates of the subjects. Metabolic
rate results showed that the contribution of
carbohydrates as a energy source increased from 43.5 ±
13.7% with the placebo, to 52.0 ± 6.7% with the PN
treatment (not significantly different). This observation
lead to the conclusion that PN supplementation decreases
glycogen stores compared to the glycogen stores without
supplementation. Since the findings from this study
suggest slightly more rapid plasma ammonia and urea
restoration but decreased glycogen stores, they do not
provide evidence for or against an increased need for vitamin B-6 in persons that are involved in strenuous
exercises of medium duration. / Graduation date: 1988
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27161 |
| Date | 11 March 1988 |
| Creators | Campuzano, Gloria |
| Contributors | Leklem, James E. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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