Figure 3.

The lack of AgRP-neurons is associated with a change in the distribution of SNS output onto peripheral tissues that precedes obesity. Representative immunohistochemistry for c-fos in naive (left) and AgRP-ablated mice (right) after a 48-h fast in the ARC and the PVN of the hypothalamus. Scale bar=100 μm (A). Representative decrease in tissue NE content after α-MPT injection (upper panel) and, turnover rate (TR) (lower panel in histogram) (B–E) were determined on pancreas (B), liver (C), white glycolytic muscle EDL (D) and red oxidative muscle soleus (Sol) (E). Plasma insulin levels after 5-h food deprivation were measured prior (time=0) and 30 min after an intraperitoneal injection of the α2-adrenergic receptor agonist clonidine (50 nmol/kg of body weight) (F, G). (A–F) All measurements were acquired on lean naive (black bar and black circles) and lean AgRP-ablated mice (red bar and red circles) at a time point that preceded obesity (n=5–8 in each group) while Figure 3G present plasma insulin change after clonidine injection in lean naive and obese AgRP-ablated mice after obesity has established (G) (n=6–8 in each group). Displayed values are mean values±s.e.m. *P<0.05.