Ribonuclease and deoxyribonuclease activities in zinc-deficient tissues.

Abstract

Abstract Although growth retardation is a common manifestation of zinc deficiency in animals and man, biochemical mechanisms accounting for this phenomenon are not well understood. In our previous studies, ribonucleic acid (RNA)/deoxyribonucleic acid (DNA) was found to be decreased in some of the zinc-deficient tissues of experimental animals. In this study, activities of ribonuclease (RNase) and deoxyribonuclease (DNase) were investigated in the testes, kidneys, bone, and thymus of zinc-deficient, continuously pair-fed and ad libitum-fed control rats. RNase activity was measured by a modified method of Kunitz 7,9,10 and DNase activity was determined by a modified method of Sung. 11 Nucleuses were measured at both acid and alkaline pH's in all the tissues, except for alkaline RNase and DNase in the bone and alkaline DNase in the thymus, in which case the activities were too low to be measured. Whereas DNase activities showed no difference between the zinc-deficient and pair-fed control rats, the activities of RNase were increased in the zinc-deficient tissues. It is believed that the increased RNase activity may, in part, be responsible for decreased protein synthesis and growth retardation so commonly observed in many animal species, including man.