Brown1997 - Plasma Melatonin Levels

Brown1997 - Plasma Melatonin Levels
A mathematical model that incorporates
a piecewise function for NAT activity to predict melatonin
concentration.

This model is described in the article:

A mathematical model of
diurnal variations in human plasma melatonin levels.

Brown EN, Choe Y, Shanahan TL,
Czeisler CA.
Am. J. Physiol. 1997 Mar; 272(3 Pt 1):
E506-16
Abstract:

Studies in animals and humans suggest that the diurnal
pattern in plasma melatonin levels is due to the hormone's
rates of synthesis, circulatory infusion and clearance,
circadian control of synthesis onset and offset, environmental
lighting conditions, and error in the melatonin immunoassay. A
two-dimensional linear differential equation model of the
hormone is formulated and is used to analyze plasma melatonin
levels in 18 normal healthy male subjects during a constant
routine. Recently developed Bayesian statistical procedures are
used to incorporate correctly the magnitude of the immunoassay
error into the analysis. The estimated parameters [median
(range)] were clearance half-life of 23.67 (14.79-59.93) min,
synthesis onset time of 2206 (1940-0029), synthesis offset time
of 0621 (0246-0817), and maximum N-acetyltransferase activity
of 7.17(2.34-17.93) pmol x l(-1) x min(-1). All were in good
agreement with values from previous reports. The difference
between synthesis offset time and the phase of the core
temperature minimum was 1 h 15 min (-4 h 38 min-2 h 43 min).
The correlation between synthesis onset and the dim light
melatonin onset was 0.93. Our model provides a more
physiologically plausible estimate of the melatonin synthesis
onset time than that given by the dim light melatonin onset and
the first reliable means of estimating the phase of synthesis
offset. Our analysis shows that the circadian and
pharmacokinetics parameters of melatonin can be reliably
estimated from a single model.

This model is hosted on
BioModels Database
and identified by:
BIOMD0000000672.
To cite BioModels Database, please use:
Chelliah V et al. BioModels: ten-year
anniversary. Nucl. Acids Res. 2015, 43(Database
issue):D542-8.

To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.