*2.2. GH Improves Energy Homeostasis in CKD Mice*

We utilized a food-restrictive strategy to study the pharmacological effects of GH in CKD mice beyond appetite stimulation and their consequent body weight gain (Figure 1D). Two-stage subtotal nephrectomy for CKD mice and a sham procedure for control mice were also performed. Eight-week-old CKD or sham mice were housed individually. Mice were given GH (10 mg/kg/day, intraperitoneal) or vehicle for six weeks. For this dietrestrictive study, vehicle-treated CKD mice were fed ad libitum, while the other mouse groups (GH-treated CKD mice as well as GH-treated or vehicle-treated sham mice) received an energy intake amount equal to that of vehicle-treated CKD mice (Figure 1E). Mice were sacrificed at the age of 14 weeks old. Serum and blood chemistry of mice are listed in Table 2. Vehicle- or GH-treated CKD mice were uremic, as they had a higher concentration of BUN and serum creatinine than sham mice. We verified that daily GH treatments resulted in high circulating concentrations of human GH in mice. Mean circulating human GH was not different between GH-treated CKD (325.3 ± 65.3 μg/L) and GH-treated control mice (364.6 ± 76.4 μg/L), whereas no human GH was detected in CKD or control mice receiving vehicle. A significant increase in weight gain in GH-treated CKD mice relative to vehicletreated CKD mice was observed at day 21, and the trend remained significant for the rest of the study (Figure 1F). In addition, GH normalized fat and lean mass content, weight of gastrocnemius, resting metabolic rate, and in vivo muscle function (rotarod activity and grip strength) in CKD mice (Figure 1G–L).

**Table 2.** Serum and blood chemistry in mice from diet-restrictive study. Eight-week-old CKD and sham mice were treated with GH (10 mg/kg per day), or normal saline as a vehicle for six weeks. CKD mice were fed ad libitum. The other mouse groups received an energy intake amount equal to that of CKD + Vehicle mice. BUN, blood urea nitrogen. Results are analyzed and presented as in Table 1. <sup>a</sup> *p* < 0.05, significantly higher than Sham + Vehicle mice.

