6
The removal of the NaCl renders the cell more resistant to lysis: one
concludes, therefore, that the negative ion is the dominant one, for when NaCl is
re-supplied the cell resistance again falls.
The fact of the increase of resistance of RBCs following removal of. NaCl
has been noticed previously by Bang (Biochem. Zeit. XVI, p. 225).
(4) Augmentation of the acidity of a suspension of RBCs by the passage of
CO 2 causes lysis. RBCs suspended in 0·85 per cent. NaCl are rapidly lysed by
the passage of CO2; suspended in 8 per cent. sugar they are not lysed; in 2 per
cent. NaCl lysis is hindered until Hb is reduced; in sodium citrate 2 . 55 per cent.
Hb is reduced, no lysis; in Na2CO 3, 1 i n 3 3 0 0 i n 0 · 8 5 p e r c e n t . N a C l , l y s i s ; i n
NaHCO3 I in 2000 in 0·85 per cent. NaCl, reduction of Hb, slight lysis after a
long time; defibrinated goat blood was not lysed, but, when diluted with 1 per
cent. NaCl lysis quickly followed. Lysis by CO2 seems to depend on the chemical
composition of the medium of suspension: w h e n i t c a n a c t d i r e c t l y o n t h e R B C s
lysis is rapid, if, however, there is an unsaturated substance such as NaH CO 3
present, lysis is delayed until the affinities of that substance have been satisfied.
Serum appears to absorb a large volume of CO 2.
Experiments by Hamburger and Van Lier (related in Engelmann's Arch.
Physiol. page 492, 1902) show that by the passage of CO 2 through blood or
through a suspension of RBCs in salt solution the alkalinity of the fluid is increased.
To what extent this occurs in the circulating blood when there is an excess of
CO2 in the air breathed does not seem to have been ascertained.
No such formation of alkalinity is observed after the passage of CO 2 through
RBCs freed from NaCl and suspended in isotonic sugar or Na 2SO4 solutions.
The explanation offered by the above-named authors is that CO 2 penetrates
the RBCs and reacts with their protein contents forming carbonates. The
envelope is permeable to kations so Cl′ passes in and CO 3″ and HCO3′ pass out,
rendering the suspending fluid alkaline. For every CO 3″ molecule passing out two
Cl′ molecules must pass in and likewise sufficient water to equalise the osmotic
pressure. Hence the lysis of the RBCs. When RBCs are suspended in sucrose
there is no interchange of kations and no lysis; when suspended in Na 2SO4 the SO4 ″
balances the CO3″ and there is no entrance of water and so no lysis. If a neutral
salt of a tribasic acid could be found for a suspending fluid which had no specific.
action on RBCs and did not react with CO 2, lysis on the passage of CO 2 would
probably not occur, for the RBCs would lose water.
(5) To find if treatment with a foreign serum has any effect on the resistance
of RBCs to lysis by hypotonicity, guinea-pig RBCs were subjected to the action
of horse serum which normally has scarcely any lytic action on them, though it
agglutinates them.
Washed guinea-pig RBCs were divided into three portions of 1. 5 cc each,.
A was suspended in 10 cc of 0.85 per cent. NaCl, B in 10 cc of fresh horse serum,
C in 10 cc of heated horse serum 55°C, and the three tubes were kept at 37°C
for 2 hours, then centrifugated, washed twice in salt solution and put up with
hypotonic NaCl solutions with the result shown below, expressed in percentages of
NaCl:—
A
B
C
Salt.
Heated Horse serum.
Fresh Horse serum.
Complete lysis ... ... · 3 9 1
· 3 5 7
· 3 4 0 p e r c e n t . N a C l .
Treatment with heated horse serum raised the resistance of guinea-pig RB Cs
so that complete lysis did not occur till a tube containing 0.034 per cent. NaCl
less was reached, and treatment with fresh horse serum prevented complete lysis
still more, i.e., until a tube containing 0.051 per cent. NaCl less was reached.
The agglutination of the RBCs was on this occasion only slight, so this can have
exercised no mechanical interference with lysis.