Fig. 4: Effect of central IGF1 on various metabolic parameters in wild-type mice

. Glucose and insulin responses were measured after ICV injection of IGF1 or anti-IGF1, or ARC injection of AAV-Igf1 injection. a & b Free-fed and fasting blood glucose and serum insulin levels after IGF1 injection. (c & d) Free-fed and fasting glucose and serum insulin levels after AAV-Igf1 virus injection. e & f Glucose tolerance tests (GTT) after IGF1 or AAV-Igf1 injection. Glucose (2 g/kg) was administered i.p after a 14 h fast (mouse age: 13 weeks). g & h Insulin tolerance tests (ITT) after IGF1 or AAV-Igf1 injection. Insulin (0.75 U/kg) was administered i.p. after a 4 h fast (mouse age: 12 weeks). i & j Free-fed and fasting (4 hr fast) blood glucose and serum insulin level after anti-IGF1 injection. k & l GTT and ITT after anti-IGF1 injection. (m) Immunoblots of insulin receptor β subunit and Akt in liver after AAV-Igf1 virus injection. n Ratio of p-Akt, p-IR β in liver of AAV-Igf1 mice relative to AAV-GFP mice (quantitative analysis was normalized by total IR or total Akt). o Immunoblots of UCP1 expression in brown adipose tissue (BAT) after AAV-Igf1 virus injection. p Ratio of UCP1 expression in BAT of AAV-Igf1 mice relative to AAV-GFP mice. Data are repeated twice and expressed as means ± SD. *P < 0.05, **P < 0.01 vs. saline or AAV-GFP group, n = 10