Serum concentration time-course of rmhTNF-α (40μg/kg, i.m.) in rhesus monkey. 4 rhesus (2 females and 2 males) monkeys received a single i.m. administration of rmhTNF-α (dissolved in PBS) at a dose of 40 ug/kg. Blood samples were collected at time points of 1, 2, 3, 4, 6, 8, 10 hrs post-dosing via the hind limb saphenous vein and the serum was divided. The concentrations of rmhTNF-α in serum samples were determined by ELISA. The time for rmhTNF-α to reach its maximum serum concentration after administration differed greatly among monkeys. The average time was 1.7 hrs. The maximum serum concentrations of the animals ranged from 575 to 1120 pg/ml which also varied greatly (Supplement Figure). The elimination of rmhTNF-α in rhesus monkeys was also evaluated with the one-compartment model. The average half life in circulation was 1.9 hrs.