The in vivo and in vitro effects of selenium on some of the hydrolytic enzyme activities from tissues of normal and vitamin E-deficient chicks

Abstract

Tissues from chicks with exudative diathesis symptoms resulting from vitamin E-deficiency showed that there were increases in the hydrolytic activities of β-glucuronidase, cathepsin and acid phosphatase when compared with chicks reared on vitamin E-sufficient diet. The increase was in the magnitude of 2-fold for β-glucuronidase, 4-fold for cathepsin and 1-fold for acid phosphatase. Oral administration of a single dose of selenium (1.5 mg/kg body weight) suppressed the activities of the hydrolytic enzymes in chicks fed a vitamin E-deficient diet when analyzed 24 hours later. The in vivo effect of selenium (suppressing the hydrolytic enzyme activities) was greater after 4 weeks on the vitamin E-deficient diet but decreased as the time of experiment increased. Homogenizing tissues in 0.25 M sucrose solution containing 0.15 ppm selenium as NaSeO₃ (in vitro) showed that selenium at this level did not suppress the hydrolytic enzyme activates. Chicks (reared on a vitamin E-deficient diet) with muscular dystrophy-like symptoms showed no increase in liver hydrolytic enzyme activities. Oral administration of selenium exerted no effect on hydrolytic enzyme activities. However, hydrolytic enzyme activities of the breast muscles from dystrophic chicks increased β-glucuronidase 4-fold, cathepsin 5-fold and acid phosphatase 1-fold, when compared to normal chicks. Selenium (1.5 mg/kg body weight), given to chicks orally in a single dosage 24 hours prior to sacrificing, suppressed the enzyme activities slightly, but not as great as that observed in the exudative diathesis studies. The in vitro studies of selenium effect on the hydrolytic enzyme activities indicated that selenium exerted no effect on the hydrolytic enzyme activities in the tissues of vitamin E-deficient and normal chicks. ...