A Histological Study on the Effect of Whey Protein on Liver and Skeletal Muscle with or without Exercise in Adult Male Albino Rats

Abstract Introduction Whey protein provides a rapid source of amino acids that the muscles can utilize. Whey protein is frequently used by people to increase their strength and improve sports performance. However, other people use whey protein as a dietary supplement because of its beneficial effects without performing any exercise. Aim of the Work to evaluate the effect of whey protein with/or without exercise on the histological structure of the liver and skeletal muscle in adult male albino rats. Materials and Methods Twenty adult male albino rats with weight ranged from 150 to 200 grams were used in this study, rats were randomly divided into two main groups: Group I (Standard diet group): subdivided into two subgroups. Subgroup IA (Standard diet, sedentary): left without intervention. Subgroup IB (Standard diet, exercise-trained): subjected to exercise training. Group II (Whey protein group): received high dose of whey protein daily (6 gram/kilogram) by oral gavage and were further subdivided into two subgroups. Subgroup IIA (Whey protein, sedentary). Subgroup IIB (Whey protein, exercise-trained): received whey protein within 30 minutes after exercise training. Rats of subgroups IB and IIB were subjected to swimming exercise training in swimming basin for four weeks, five days per week, in which the exercise time was increased gradually throughout the four weeks of the study. Liver and gastrocnemius muscle were subjected to microscopic examination, morphometric and statistical studies. Results Histological, morphometric, and statistical studies of liver of subgroup IB were nearly similar to that of subgroup IA. Histological examination of liver of subgroup IIA showed congestion of central vein and portal vein with surrounding mononuclear cellular infiltration and increased mean collagen percentage as compared to other subgroups. It also showed vacuolated hepatocytes with shrunken, irregular, and heterochromatic nuclei. Meanwhile, subgroup IIB showed improved hepatic architecture than subgroup IIA. Histological examination of gastrocnemius muscle of exercise-trained subgroups IB and IIB showed increase in mitochondrial content, mean glycogen optical density, and mean muscle fiber diameter with appearance of splitting and central nuclei, which were more pronounced in subgroup IIB as compared to subgroup IA. Meanwhile, subgroup IIA showed significant decrease in mean muscle diameter as compared to subgroup IIB, however it showed nonsignificant increase in mean diameter when compared to subgroup IA. Conclusion High intake of whey protein without physical exercise has its degenerative effects on liver, also it showed non-significant increase in mean diameter of skeletal muscle as compared to rats fed standard diet. Thus, whey protein should be taken within its recommended dose and accompanied by physical exercise.