Circadian and Menstrual Cycle Variation in Serum Vitamin B-6 Levels in Baboons

Publisher Website
Google Scholar
Abstract
Serum vitamin B-6 levels were measured at 02:00, 09:00, 12:00, 15:00, and 21:00 hours for two consecutive days in normally cycling female baboons to determine the extent of circadian variability. Seven baboons were sampled during the follicular phase of the menstrual cycle while 14 were in the luteal phase. Analysis of the data indicated significant variability over the 48-hour period during the follicular phase of the menstrual cycle but it was not a repeating circadian rhythm. No significant differences were detected between sampling times in baboons in the luteal phase. The mean of the follicular phase values was significantly higher than the mean of the luteal phase values. Four baboons were sampled throughout one normal menstrual cycle. These serum vitamin B-6 levels, when subjected to linear regression analysis, had the following characteristics: best fit regression line for the complete menstrual cycle (Y = 12.584 + 0.02265X, Sxy 3.44), for the follicular phase (Y = 13.958 + 0.1632 X, Sxy 3.689) and for the luteal phase (Y = 13.32 + (-0.0685) X, Sxy 3.35), where Y is the ng/ml of vitamin B-6 in serum and X is the day of the menstrual cycle. These slopes were not significantly different from zero. Since endogenous estrogen and progesterone levels could not be statistically correlated with serum vitamin B-6 levels in any of these experimental conditions, it was concluded that these sex steroids had no significant effect on peripheral levels of vitamin B-6.

This publication has 20 references indexed in Scilit: