Effect of intravenous administration of insulin, glucagon and leptin on pERK1/2 cell expression within the hypothalamic arcuate nucleus (ARC) and paraventricular nucleus (PVN)
A) Leptin (1 mg·kg− 1) significantly reduced pERK1/2 cell expression within the ARC, while insulin (10 U·kg− 1) and glucagon (100 μg·200 μl− 1) did not significantly affect pERK1/2 expression, when compared to control sham group, 60 min post-injection.
B) Photomicrographs showing the localization of pERK1/2 staining in the hypothalamic ARC. Dotted line shows the ARC nucleus; 3V: third ventricle.
C) Photomicrograph showing the localization of pERK1/2 staining in the hypothalamic ARC of an animal administered with glucagon (100 μg·200 μl− 1). Arrows indicate cell bodies; 3V: third ventricle.
D) Photomicrographs displaying the localization of pERK1/2 staining in the PVN showing no significant difference between groups.
*p < 0.05; **p < 0.01; #p < 0.001.