Brain IGF-1 Receptors Control Mammalian Growth and Lifespan through a Neuroendocrine Mechanism

Figure 2

Growth and Postnatal Development of the Somatotropic Axis in Mutant and Control Mice

(A) bIGF1RKO^+/− mice had significantly delayed growth, from age 18 d onwards.

(B) bIGF1RKO^+/− pituitaries were small from age 10 d onwards (n = 10 per group).

(C) Pituitaries from mutants contained little GH (n = 5 per group).

(D) Data from (C) expressed per milligram of pituitary protein revealing a selective drop at age 20 d.

(E) In control mice, serum IGF-I increased rapidly after age 10 d (in response to endogenous GH), but remained low in bIGF1RKO^+/− mice.

(F) Similar to IGF-I (E), the postnatal surge of ALS in controls was absent from bIGF1RKO^+/− mice (n = 5 per group).