Ex vivo multinucleated osteoclast formation in bone marrow cultures of 3-month-old WT, Ghsr−/−, ob/ob, and ob/ob.Ghsr−/− mice (A) and of WT mice treated with 100 nm ghrelin (AG), 10 nm leptin, or a combination (B). Number of osteoclasts in distal metaphysis of 3-month-old (C) and 6-month-old (D) male WT, Ghsr−/−, ob/ob, and ob/ob.Ghsr−/− mice. *, P < 0.05; **, P < 0.01; ***, P < 0.001.