Stability of Serum Cholesterol Concentration in Rats after Injection of Deoxyribonucleic Acid (DNA).

Abstract

Savitsky( 1-3) recently reported that a small quantity of heterologous bovine deoxyribonucleic acid (0.05 to 2.5 mg per rabbit) can produce an irreversible fall in serum cholesterol concentration in rabbits. The fall occurs after a latent period approximately proportional to the dose administered-the higher the dose, the shorter the latent period.If these findings can be confirmed and shown to have general validity, they would be of great importance, practical and theoretical. Apart from the possibility of specific therapeutic application of DNA in cases of hypercholesteremia, it would be possible to develop a direct test for a specific biological effect of DNA in mammals. In this report, we have attempted to repeat the experiments reported in Savitsky(1-3) on rats.Methods. Female Wistar rats weighing 200-220 g and with serum cholesterol levels of 0.85-1.00 g/1 were divided into 4 groups, viz.: Group 1, 7 control rats; Group 2, seven rats fed a hypercholesterolemic diet; Group 3, 8 rats receiving DNA; Group 4, 8 rats fed a hypercholesterolemic diet and receiving DNA.The non-hypercholesterolemic diet consisted of standard biscuits containing maize, oats, barley, fine bran, crumbs of pastry, peanut, cooked soya, brewer's yeast (4%), meat, fish, a mineral concentrate, codliver oil (0.5 % ) and supplements of Vit. A (55,OOO I.U./lOO kg) and Vit. D (50,OOO I.U./lOO kg). The hypercholesterolemic diet consisted of standard biscuits (48.2%), butter (40%), cholesterol ( 5 % ) , thiouracil (0.3 % ) , cholic acid (2%), codliver oil (0.5%), and brewer's yeast (4%). The rats were given 30 g of either diet per day per animal with water ad libitum.DNA was obtained by the method of Kay, et al. (4). I t contained less than 3 % proteins and less than 1 % ribonucleic acid; its water content (constant weight 110') was 27%;