AJP - Regulatory, Integrative and Comparative Physiology, Vol 267, Issue 2 502-R507, Copyright © 1994 by American Physiological Society
Comparative studies on tryptophan binding to hepatic nuclear envelopes in Sprague-Dawley and Lewis rats
H. Sidransky and E. Verney
Department of Pathology, George Washington University Medical Center, Washington, District of Columbia 20037.
Since Lewis rats are susceptible to many inflammatory diseases and have
been used in an experimental model of the eosinophilia-myalgia syndrome, we
investigated whether Lewis rats would respond to L-tryptophan as have
Sprague-Dawley rats reported earlier. In this comparative study using
females of both strains, we observed a decrease in the affinity of in vitro
L-tryptophan binding to hepatic nuclei and nuclear envelopes of Lewis rats
compared with Sprague-Dawley rats. However, in vivo stimulatory effects of
administering L-tryptophan on hepatic polyribosomal aggregation, protein
synthesis, and nuclear RNA release were similar in both strains. In vitro
[3H]tryptophan binding to hepatic nuclear envelopes, using L-tryptophan
implicated in cases of the eosinophilia-myalgia syndrome, revealed less
specific binding than when using nonimplicated L-tryptophan in both
strains. The possible significance of the quantitative difference in the
binding affinity of L-tryptophan to hepatic nuclei of Lewis rats compared
with those of Sprague-Dawley rats is as yet undetermined.
