ABSTRACT
This study was done to evaluate the effect of dietary protein on serum lipids in mature and immature male rats. Two groups of rats were used, immature [3-month old] and mature [9-month old], they were divided according to the type of food provided into 2 subgroups: Control subgroup fed on balanced diet [BD] mixed with 5% [w/w] casein and subgroup 2 fed on BD mixed with 5% [w/w] row soybean. All groups were fed their special diet regimen for four weeks. Serum triglycerides, total cholesterol, high density lipoprotein cholesterol [HDLC] and low density lipoprotein cholesterol [LDLC] were measured. Soybean protein dict caused highly significant decrease in serum triglyceride total cholesterol and HDLC levels in all groups of animals compared with controls fed on casein protein. While LDLC level in all groups showed insignificant decrease