Effect of methionine free total parenteral nutrition and insulin
like growth factor-i on tumor growth in rats.
Yoshida, Shogo, Junji Ohta, Yuichirou Shirouzu, Nobuya Ishibashi,
Yoshikazu Harada, Hideaki Yamana, and Kazuo Shirouzu.
First Department of Surgery, Kurume University, School of Medicine,
67 Asahi-machi, Kurume-shi, Fukuoka, 830, Japan
APStracts 4:0062E, 1997.
The objectives of this study were to evaluate the effect of insulin
like growth factor-I (IGF-I) on fractional synthesis rate (FSR) of
muscle and whole body protein breakdown rate (WPBR) during methionine
free total parenteral nutrition (MTPN). We also determined whether
the inhibition of endogenous methionine availability reduced tumor
protein synthesis. AH109A hepatoma cells were inoculated onto the
backs of Donryu rats on day 0. On day 10, the rats were catheterized
for TPN and assigned into 4 groups: 1) standard TPN (STPN), 2)
STPN+IGF-I, 3) MTPN, 4) MTPN+IGF-I. Addition of IGF-I to MTPN reduced
the loss of body weight by both increasing muscle FSR and reducing
WPBR. The tumor FSR did not differ between MTPN+IGF-I and MTPN. The
methionine extraction ratio from the liver was negative with
MTPN+IGF-I, but positive in the other groups. We concluded that IGF-I
blockage of endogenous methionine release from peripheral protein
sites was associated with a shift to liver derived methionine with no
change in tumor growth in MTPN treated rats.
Received 18 October 1996; accepted in final form 28 January 1997.
APS Manuscript Number E517-6.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 12 March 1997