Comparison of Different Protein Diets on Renal Function and Bone Health in Normal Growing Female Rats

Abstract

Feeding animal proteins but not milk proteins, short‐term at conventional amounts, has been reported to alter renal function. The objective of this study was to investigate effects of different protein diets on renal function and bone health. Female rats (n=10/group) were individually housed in metabolic cages and fed ad libitum isonitrogenous and isocaloric diets consisting of either 10% casein or 10% krill protein concentrate (KPC) isolated from Antarctic krill (Euphausia superba)for 4 weeks. Results showed that rats fed KPC had lower (P<0.001) relative kidney weights compared to the rats fed casein. Rats fed KPC had lower kidney calcium (Ca) (P=0.008) and phosphorus (P) (P<0.001) levels compared to rats fed casein. Urinary output was higher (P=0.03) in the rats fed KPC than casein. However there were no changes in renal function indicated by absence of differences in serum levels of creatinine, blood urea nitrogen, protein, Ca, and P between the groups. There were no difference (P=0.49) in dietary Ca or P intake between the treatment groups. Urinary Ca (P=0.06) and P (P=0.69) excretion was not significantly different. There were no differences in femur total bone mineral content or femoral Ca and P. Femur strength measured by three‐point bending test was similar between rats fed KPC and rats fed casein. Based on the study results, short‐term consumption of KPC appeared comparable to casein for renal and bone health.