CTRP3 administration decreases blood glucose in mice. Injection of mice with 2 μg/g body weight of purified recombinant CTRP3 (A) increased circulating CTRP3 levels 3-fold (B) and was sufficient to lower blood glucose in normal C57BL/6 (C) and obese and diabetic (ob/ob) mice (D) without altering serum insulin, glucagon, non-esterified fatty acids (NEFA), leptin, or adiponectin levels (E–I). Each bar represents the mean ± S.E. (error bars) (n = 8). *, p < 0.05.