The urinary excretion of 4-pyridoxic acid (PIC), the principle
end-product of vitamin B₆ metabolism found in human urine, was
measured in two populations in whom altered vitamin B₆ metabolism
has been reported: in women who use oral contraceptives and in
mental retardates with and without Down's syndrome.
In the first study 4 women who had been taking an oral contraceptive
for 2 to 12 months served as experimental subjects; two
women who did not use an oral contraceptive pill served as control
subjects. They were placed on a constant diet that met the requirements
for all essential nutrients. The study lasted for 11 days.
During this period five 24-hr urine specimens were collected from
each subject and were analyzed for 4-pyridoxic acid as well as for
total creatinine.
The urinary excretion of PIC by the subjects using an oral contraceptive was similar to that by the control group in this study
and that by normal women subjects reported in the literature. The
results of this study suggest that the alteration in vitamin B₆ metabolism observed in women using steroid contraceptives is not reflected
by any change in urinary excretion of PIC. In general all subjects
excreted more PIC during the latter part of the study than the initial
stage, probably reflecting an adjustment to the higher intake of the
vitamin supplied by the diet. Also, there was an inverse relationship
between the urinary excretion of PIC and the body weight of the
participants.
In another study the excretion of PIC before and after pyridoxine
(PIN) loading was studied in 12 patients with Down's syndrome and
12 mentally retarded controls without Down's syndrome. Three
mongoloids and three non-mongoloids of the same sex and matched
for age and weight were studied at a time for 6 days. They received
a constant diet that was adequate in all essential nutrients for man.
PIC was determined in urines collected on days 1, 5, and 6, 50 mg
of pyridoxine being orally administered on day 5. Data show that
the basal urinary excretion of PIC is similar in the mongoloid and
control subjects. The total increase in PIC excretion by patients
with Down's syndrome during the two days following the ingestion
of the test dose of pyridoxine averaged 22.03 mg, while the excretion
by the controls averaged 19.34 mg. The larger excretion of PIC by Down's syndrome patients compared with controls following
pyridoxine loading was significant (P < 0.05). An explanation for
this greater excretion by mongoloids is proposed. / Graduation date: 1973
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/26942 |
| Date | 28 November 1972 |
| Creators | Young, Joey Nim-cho |
| Contributors | Miller, Lorraine T. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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