Effect of Insulin Like Growth Factor
- Author:
Jeh Hoon SHIN
- Publication Type:Original Article
- Keywords:
Energy restriction;
IGF
- MeSH:
Animals;
Diet;
Dietary Proteins;
Humans;
Insulin;
Insulin-Like Growth Factor I;
Rats;
Rats, Sprague-Dawley;
Research Design;
Spleen;
Tail;
Thymus Gland
- From:Journal of Korean Society of Endocrinology
1994;9(3):213-218
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
recombinant human IGF-I in energy-restriction model. Experimental design; Sprague-Dawley rats(n=20) weighing 90-100g were used. 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+-7.7 in 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+-110 ng/ml energy restricted group), IGF-I treatment(300 ug/day in twice sc injection for 6day) did not significantly accelerate the growth rate(body weight)(2.87+-0.20 vs. 2.70+-0.18g/day in energy restricted group).The glycemia was slightly reduced by IGF-I treatment(91.7+-5.0 mg/dl vs. 101.3+-4.5 mg/dl in energy restricted group), but it was not significant. However, the spleen and thymus weight, decreased by energy restriction, was completely normalized by IGF-I treatment.In summary, lack of a significant anabolic response to injection of IGF-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.
