Rannsóknir um hvussu súrevnistrýstið, kolsýrutrýstið og súrgan ávirka reyðblóðkroppanøringina í glarroyndum

Abstract

ín two previous essays (Magnussen 1949, 1950) the author presented in condensed form the results of studies on the influence of oxygen tension, carbon dioxide tension and hydrogen ion concentration on the production of erythrocytes in vitro. The present article gives a more exhaustive account of the difficulties bound up with such investigations and describes in more detail the author's technique which mainly differs from that of Osgood and Plum as follows:
1. The investigations were made in Warburg vessels in water, both at 38° C.
2. The vessels were kept in constant motion to prevent sedimentation (Fig. 1).
3. Agglutinations were avoided by using serum from blood kept at 2°—4° for 24 hours, and then the serum must not show any signs of hemolysis. Moreover the suspension must be kept for a period of 20 minutes before serum is added.

In section I. a comparison is made between the production of erythrocytes in 100 %, 80 %, 50 %, 40 %, 30 %, 10 %, 5 %, 2~y% % oxygen and in ordinary atmospheric air (20, 95 % 0 2 ) . The results of some of the experiments are seen in Fig. 2—7: (Fig. 2 Production of erythrocytes in vitro in air compared with nitrogen containing 2.5 % 02 . — Fig. 3—7. Production of erythrocytes in vitro in air compared with nitrogen containing 5 % 0 2 ) . The total results are shown in tables (Table 1—8), and the final results can easily be read off from Curves (Fig. 8—9) which indicate that the maximum production of erythrocytes was seen at
10—30 % of oxygen. The production was inhibited at 40 % and 5 % of oxygen and completely arrested at 50 % and 2 % %• Thus the optimal production was observed at the physiological oxygen tension.

In section II. the production of erythrocytes was similarly examined in 3 % and 6 % of carbon dioxide in relation to atmospheric air (Table 9—12). A special investigation was made to see what influence pH has on bone marrow cells in vitro. These results
may be seen in Table 13 in addition all the results are seen in a co-ordinate system; this co-ordinate system is seen in Figure 10 from which it is evident that increasing concentrations of carbon dioxide inhibit the formation of red blood cells from bone marrow in vitro. An inhibition of the same magnitude is seen when the pH in the solution is altered to values corresponding to those found in the samples with increased carbon dioxide. It may be concluded thal carbon dioxide has now effect on its own, but that the effect observed is due to the resultant increased hydrogen ion concentration in the medium. It must, however, be emphasized that these results from experiments in vitro do not exclude the possibility of decreased oxygen tension or increased carbon dioxide tension playing a part in the formation of red blood cells in vivo.

It is tempting to suggest that blood formation in vivio may be controlled indirectly, e. g. through an effect on the capillaries
in the bone marrow, perhaps via the nervous system. Further investigations are, however, necessary to decide whether this assumption is right or not.