Effect of different protein sources on the biological and biochemical parameters of rats

The current study verified the impacts of beef, whey and protein of soy sources at the levels of 10 and 15% on biological and biochemical parameters of normal rats. Forty-nine male Sprague Dawley rats, each weighing approximately 120±5g were randomly divided into seven groups each of seven rats. The initial set of subjects had only a basic diet and served as the control group. The basal diet was given to the other six groups and a supplementation of 10 and15% different protein sources for 28 days. The biological parameters (BWG, FI and FER) and biochemical parameters (blood glucose, insulin hormone and insulin resistance, ALT, AST, AlP, albumin, urea, uric acid, creatinine, lipid profile, atherogenic ratios, antioxidant enzymes and interleukins productions) were determined. The findings implied that protein type affected the mean values of biological parameters of normal rats and the high levels of animal sources led to reduce the biological parameters when compared to plant source and control group. The protein sources led to increase the organs weight especially in animal protein sources, the organs weight was increased by rising the protein intake level. The mean values of blood glucose, insulin hormone and insulin resistance of the control group were substantially lower than the other groups. The highest lipid profile recorded significant increasing in group fed on basal diet with 15% as animal protein sources followed by 10% protein except HDL-c. The highest kidney and liver functions values were found in groups fed with basal diet and 15% beef protein followed by the same level of whey protein.  Administration of high protein from different sources showed substantial increase in serum PRL, estradiol and the serum interleukin (IL1, IL6 and TNF-a) activities, but showed significantly reduction levels of serum testosterone as in relation with the control group and soy protein source. Thus, it important to regulate protein consumption especially from animal sources for long time and to make a balance between animal and plant protein sources to mitigate the risk of conditions such as infertility, liver and kidney disease, blood vessel disorders, and cardiovascular disease.