Plasma levels of insulin-like growth factor-I are reduced at one week of age in monosodium L-glutamate-treated mice.
Administration of monosodium L-glutamate (MSG) to neonatal mice produces a hypothalamic syndrome consisting of stunted growth and later development of obesity. We assayed plasma insulin (IRI), thyroxine (T4) and insulin-like growth factor-I (IGF-I) to investigate their roles in the growth of the mice. Two mg/g body weight of MSG was injected into newborn male mice daily for five successive days after birth. Plasma IRI levels were increased on the after 8 weeks of age in MSG-treated mice. There was no significant difference between the plasma T4 levels in MSG-treated mice and those in controls at any age studied. In contrast to this, plasma IGF-I levels in MSG-treated mice were reduced at one week and after. These results suggest that a decreased plasma IGF-I level contributes to the retarded linear growth which develops soon after the administration of MSG, and hyperinsulinemia contributes to the later development of obesity in MSG-treated mice.
Yamamoto
T
T
Department of Pediatrics, Kyoto Prefectural University of Medicine, Japan.
Matsuo
S
S
Ueshima
Y
Y
Inoue
F
F
Kinugasa
A
A
Sawada
T
T
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D006130:Growth Disorders / Q000139:chemically induced; D007031:Hypothalamus / Q000187:drug effects; D007328:Insulin / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009765:Obesity / Q000139:chemically induced; D012970:Sodium Glutamate / Q000008:administration & dosage / Q000633:toxicity*; D013974:Thyroxine / Q000097:blood
D007328:Insulin; D007334:Insulin-Like Growth Factor I; D013974:Thyroxine; D012970:Sodium Glutamate