In addition to regulation mediated by GH, nutritional status in an important regulator of IGF-I. Circulating levels of these peptides modulated by poor nutritional status and poorly controlled insulin dependent diabetes mellitus(IDDM). Impaired
growth
is a well recognized complication of poorly controlled diabetes. This study was designed to examine the anabolic effect or recombinant human IGF-I in energy-restriction model. Experimental design; Sprague-Dawley rats(n=20) weighing 90-100g were
sued.
Rats were fed a control diet two times a day (AM 8-11, PM 5-8) for four days after arrival and then assigned to one of three groups: control, energy-restricted, energy-restricted IGF-I treatment group. Energy restricted group was given with a
decrese of
25% in the energy without changes in the protein by feeding 88% by weight to energy-restricted diet.
During the 10days of energy restriction, the growth rate was reduced by 35%(2.70±0.18g/day in energy restricted group vs. 4.13±0.75g/day in the control group). At sacrifice, the tail lengh and weight of organs were not significantly decreased
except
the spleen and thymus(17% : P<0.05). Serum IGF-I was reduced by 19% at the end of 10days of energy restriction. The glycemia, measured each day by glucometer from blood collected at the tail, was not reduced by energy restriction(105.4±7.7in
control
group vs. 101.3±4.1mg/dl). The abundance of serum IGF-BPs was unchanged by this restriction.
Despite the 1.5 fold increase of IGF-I concentration in energy restricted IGF-I injection group at sacrifice(1994±172ng/ml vs. 1221±110ng/ml energy restricted group), IGF-I treatment(300ug/day in twice sc injection for 6day) did not
significantly
accelerate the growth rate (boy weight) (2.87±0.20 vs. 2.70±0.19g/day in energy restricted group).
The glycemia was slightly reduced by IGF-I treatment(91.7±5.0mg/dl vs. 101.3±4.5mg/dl in energy restricted group), but it was not significant. Hower, the spleen and thymus weight, decreeased by energy restriction, was completely normalized by
IGF-I
treatment.
In summary, lack of a significant anabolic responce to injection of IGF0-I during energy restriction in this study may be associated with the compensatory growth response (alterations in dietary protein utilization) which followed initial period
of
energy restriction.(J Kor Soc Endocrinol 9: 213-218, 1994)
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