Objective To investigate the serum testosterone level of aging SD male rats and the effect of marine collagen peptides(MCPs) on them.Method 48 SD male rats were randomly divided into 4 groups according to their different doses of MCPs (0 control, 2.25%, 4.50% and 9.00%) with 12 rats in each. Serum testosterone was measured at the ages of 12, 18 and 24-month. MDA contents and SOD, GSH-Px activities in blood serum were measured at the ages of 12,18 and 24-month.Results Serum testosterone levels of 12, 18 and ...