Nucleic acids of rabbit reticulocytes.

By N. S. BURT, B.A., H. G. E. MURRAY, M.A., M.D., C.M. .ND It. J. HOSSITER, -I.A., D.PHIL., B.M., B.CH. T HORELL, -61 using the technic of ulft’aviolet light. absorption developed by Caspersson and his associates (see Caspersson’3 for references) , showed that the concentration of nucleic acic! in the cytoplasm of immature red cells ‘as greater than that in mature (‘ells. Using chemical methods, he also showed thatthe concentration of phosphorus (chiefly nucleoprotein phosphorus) i’emaining after successive removal of the acid-soluble phosphorus and the lipid phosphorus was greater in the rec! cells of t’abbits that had been subjected to repeated hemorrhage. Many of these immature red! cells wet’e polychromafic and probably w’ould have appeared as reficu!ocytes hat! they been stained supravitally with brilliant d’resyl blue. This finding lent supportto the earlier suggestion of Kay36 that there is a greatet’ concenfrafion of nucleic acid phosphorus in reticulocytes. Other workers have made both chemical2’ ‘ 22 and hisfochemical5’ ‘ 62 ,64 studies on the immature cells of hone marrow and on primitive red cells from the yolk sacs of embryos,35 butfew’ observations have been made on the reticulocytes of peripheral I)lOOd. The most comprehensive observations are those of I)usf in24 who, using the rihonuclease mefhoc! of Brachet,8’ showed that the basophi!ic sui)sfance in the cytoplasm of reficuloeytes is desti’oyed i)y ribonu(’lease. In his experiments on the red cells of rabbits subjected to hemorrhage, Thon’ell 6 c!id not estimate penfose and desoxypenfosenucleic acids separately. It seemed of value, therefore, to determine the concentration of pentose and desoxypentosenucleic acids in suspensions of red cells containing immature cells and to compare the results with those obtained w’ith the histochemical met hoc!s. Iteficitlocytes were produced in the peripheral blood stream of n’abbits cit-her by the ac!minisf ration of phenylhydrazine or by successive bleedings. Thet’e ‘as an in(’I’ease in the concentration of nucleic a(’id in the red cells, coincident w’ith an in(’i’ease in the number of reticulocyfes. This nucleic acid! was of the pentose rather than the desoxypenfose type. The basophilia of the polyehromatic cells was founc! to disappear after treatment with the rihonuclease or after hyc!i’olysis w’ifh normal hyc!rochloi’ic acid. Desoxyribonuclease was without effect-. In a(!(!if ion to the increase in the concent-raf ion of pentosenucleic a(’idl then’e ‘as also an inci’ease in the concentn’at ion of both acid! soluble phosphorus and lipid phosphorus in cell suspensions containing reficulocyfes. Incidentally, dat a are present cc! on the concentration of acid! soluble phosphorus, lipic! phosphorus and nucleic a(’i(!s in i’ec! dells and polymorphonucleai’ leukocytes ft’om normal rabbits. 1)etails of the d!istribution of the various lipids in the i’ecl cells an(! in the polymorphonuclear leukocyfes of the n’abbithave alreac!y been described!.’2