Fig. 7

Effects of REGN1033 on muscle mass and exercise performance in aged mice. a TA and GA muscle weights of 24-month-old mice receiving REGN1033 or isotype control antibody treatment (10 mg/kg) for 3 weeks. Muscle weights were normalized by starting body weights and expressed as percent changes from isotype control. b Isometric force as a function of stimulation frequency of TA muscle at the end of 3 weeks of treatment with isotype control antibody or REGN1033. Same as in b but depicting peak tetanic TA muscle force (c) or specific force (d). TA (e) and GA (f) muscle weights at the end of 3 weeks of treatment with REGN1033 or isotype control antibody (10 mg/kg) from 19-month-old C57BL/ mice either left sedentary or during a three week exercise regimen. Muscle weights were normalized by starting body weights and expressed as percent changes from isotype control. g, h Treadmill exhaustion and maximal running capacity tests measured in the mice described in e, f. All groups had six to eight animals. Data are means ± SEM. *P < 0.05, **P < 0.01, ****P < 0.0001 vs. sedentary isotype control and ^## P < 0.01 vs. sedentary REGN1033