Hormone specific alterations of t4, t3, and reverse t3 metabolism
with recent ethanol abstinence in humans.
Kaptein, E. M.
Department of Medicine, University of Southern California, Los
Angeles, California 90033
APStracts 3:0205E, 1996.
Effects of recent alcoholic withdrawal on T4, T3 and rT3 metabolism
were determined by serum tracer kinetic studies in recently abstinent
alcoholics without overt hepatocellular injury or caloric
deprivation. Data were compared to normal subjects using a 3-pool
model, with rapidly and slowly equilibrating pools exchanging with
serum. Significant differences included: 1) reduced serum total rT3
levels (to 69% of normal) and rT3 degradation rates (to 61%), 2)
increased rT3 binding in rapidly (to 557%) but reduced binding in
slowly (to 13%) equilibrating tissues, with opposite effects on rT3
fractional transfer rates to serum from rapidly (to 7.5%) and slowly
equilibrating sites (to 669%), 3) increased T4 fractional transfer
rates from serum to rapidly equilibrating tissues (to 122%), and 4)
increased T4 binding to both rapidly (to 195%) and slowly (to 190%)
equilibrating tissues. T3 kinetics were not significantly altered.
Thus, recently abstinent alcoholics have hormone specific alterations
of T4, T3, and rT3 transfer, distribution and metabolism, distinct
from other nonthyroidal illnesses or caloric deprivation. Further,
these data indicate separate transfer processes for T4, T3 and rT3
from serum to tissue sites, and hormone specific tissue binding
characteristics in humans in vivo.
Received 9 April 1996; accepted in final form 12 September 1996.
APS Manuscript Number E174-6.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 November 1996