Evidence of kidney dysfunction and injury in NL male mice. Mc4rKO mice are protected against neonatal leptin-induced renal injury. GFR (A, milliliters per minute), excretion of albumin (B, milligrams per 24 h), and the early renal damage markers NGAL (C, picograms per 24 h) and KIM-1 (D, picograms per 24 h) are shown. Data are expressed as mean ± SEM (n = 5–6 per group). Means not sharing the same letter are significantly different from each other (P < 0.05) by generalized least squares (GLS) regression analysis. Data for females were similar.