17
TABLE 2.
Defibrinated rabbit blood
85 per cent. salt
...
Sheep R.B.Cs.
...
Citrated rabbit blood ...
85 per cent salt
...
Sheep R.B.Cs.
...
...
...
...
...
...
...
...
...
...
...
...
.45 cc.
1.50cc.
.05cc 1.05cc.
.90 cc.
. 0 5 c c . 0 5 c c .
.05 cc
Complete lysis.
Nil lysis. (1 .2 per cent. NaCl).
Defibrinated goat blood
85 per cent. salt
Sheep R.B.Cs.
Citrated goat blood ..
85 per cent. salt
...
Rabbit R.B.Cs.
...
...
...
...
...
...
...
...
...
...
...
...
20 cc.
1.75 cc.
.05 cc.
1.25 cc.
.7 cc.
.05 cc.
Complete lysis.
Nearly complete lysis. (1 . 3 per cent.
N a C l ) .
To determine whether the very marked difference between defibrinated and
citrated bloods was due merely to the increase of tonicity consequent on the presence
of 1 per cent. sodium citrate in the latter further experiments were made.
(a) On the inhibitory power of hypertonic solutions on lysis.
In a preliminary estimation it was found that the tonicity of a sheep serum was
equivalent to 1 per cent. NaCl. By the addition of measured weights of dry NaCl
the tonicities of three other quantities of this serum were raised to 1 . 2 per cent., 1.4
per cent. and 1 . 6 per cent. NaCl, respectively, when tested with 0 . 05 cc. rabbit R.B.Cs.
Serum A (tonicity 1.0 per cent.
NaCl )
0.65 cc. gave
Complete lysis.
B
(
1 . 2 7
)
1.05
C
(
1.4
)
1.25
D
(
1.6
)
1.65
So it is evident that a comparatively small increase in tonicity has a pronounced
influence in the direction of hindering lysis.
(b) On the relation between the tonicities of sodium chloride and sodium citrate.
Using any R.B.Cs. as indicator, it proved that approximately three times as much
sodium citrate by weight was required to prevent lysis by hypotonic solutions as was
required of sodium chloride.
As long as this relation of 3 citrate to 1 chloride is borne in mind, solutions of
any desired tonicity containing a mixture of the two salts in due proportions can be
prepared. Thus 1 gramme sodium chloride plus 3 grammes sodium citrate dissolved in
100 cc. water is equivalent in tonicity to a 2 per cent. solution of sodium chloride.
It will be noticed under experiment (a) that the increased tonicity of the medium did
not altogether abolish lysis even u.p to 1 . 6 per cent. NaCl but that an increased
quantity of serum was required to accomplish it. In fact in the presence of 1.6
per cent. NaCl, 2 . 6 times as much serum was required to give complete lysis as was
required in its absence.
In table 1, it may be further noticed that 1 . 95 cc. of citrated blood with a tonicity
of 1 . 6 per cent. NaCl failed to lyse completely the quantity of R.B.Cs. lysed by 0 . 35 cc.
of defibrinated blood, i.e., that more than 5 parts of citrated. blood failed to accomplish.
the same degree of lysis as 1 part of defibrinated blood.
Similarly, even when the tonicity was reduced to normal by dilution with 0 . 85 per
cent. NaCl., 0 . 35 cc. citrated blood only produced slight lysis in contrast with the
complete lysis produced by 0 . 35 cc. defibrinated blood.
Likewise, in table 2, the tonicity of the citrated bloods used does not entirely
account for the total absence or hindrance of lysis there displayed.
It would appear then that citrate has some effect on blood in the way of hindering
its lytic power quite apart from the tonicity of the solution.