Protein digestive power of Sperm\vhale Pancreatic Enzyme
Yasutaro Ishikawa, Setsuzo Tejima
The feeding habit of cetacea is very peculiar, that is, they do not takeany carbohydrates but depends entirely on protein food.
These may have some special digestive enzymes and the authors'attention were attracted by pancreatic enzyme and anticipated that thismay be a strong protease.
Also cetacea eats live feed so that the digestive enzyme the feed posses
may be utilized in the alimentary tract. If this is cqnsidered, the digestive
enzyme excreted by whales may be only a small quantity.
If they are strong as first anticipated, there may be some industrial
use for them because the quantity of whale pancreas is very large.
At any rate, it is necessary to ascertain the protein digestive power ofpancreatic enzyme. Fortunately, the authors were able to obtain pancreas
from two sperm whales at the Ayukawa whaling· ground and experiment
was carried on with these.
Both of the sperm whale were about 40 ft. long and they were not
fresh because 30 hours elapsed from the time they were caught to thetime when they were dissected.
After dissection, the pancreas was removed, fatty tissues, connective
tissues and other unnecesary parts were removed, as much as possible,
placed in cans immediately frozen and brought to the laboratory. On theway, special attention was paid so that the temperature did not rise. Thiswas well minced with a meat mincer, mixed and stirred until uniform,
stored in a refrigerator and taken out as the experiment required.
Determination of digestive power was carried on along the pancreatin method described in the Japan Pharmacopoeia. That is, 0.2% casein
solution was used as substrate, extracted solution obtained by extracting
a fixed quantity of minced pancreas with fixed quantity of water, was added
to 5 c.c. of this in stages, water was added until the total content became
10 c.c. This was made to react for one hour at 40°C, 3 drops of a solution
composed of 10 c.c. of alcohol, 1 c.c. of glacial acetic and 9c.c. of water was

.Yasutaro Ishikawa, Setsuzo Tejima

56

added to this digestion solution and the presence. of slight tutbidity was
taken as the end of digestion.
Preparing of casein solution is as follows that is, refined casein byHammersten's method, is dried in a H2S04 desiccator, 2 g. of this is removed
and well dispersed in about 50 c.c~ of water. To this is added 2 c.c. of 0.1
N KOH, shaken to dissolve and made up to 100 c.c. with water after it has
dissolved.
Experimental objects were to determine, the digestive p:>wer of fresh
pancreas (those which went trough the above procedure), the relation between time and activition of digestive power when it was autolysed at 40°C
in neutral reaction and the same relation in autolysis at 40°C when sligtly
acidic (initial pH 5.4) and the digestive power when minced pancreas wasdried with ~cetone and pulverized.
Furthemore, the same experiment was carried on with cow pancreas
and the digestive p:>wers of cow pancreas and whale pancreas werecompared.
Experiment
1. Protein digestive power of fresh pancreas.
Enzyme solution made by dispersing 1 g. of minced pancreas 'in 100 c.c.

of water is filtered with fluted filter paper. The analysis of this mincedpanccreas is 73.7% moisture and, 26.3% dried matter but this dried matter
contained considerable quantity of fat. Therefore, 100 c.c. of this extraction
liquid may be equivalent to ea. 0.2 g. of dried pancreas so that in such an
estimation method, 0.2 g. is assumed to be not such a discrepancy. By
doing this, it will be simple to calculate the unit quantity of pancreas which
digested so many times casein because the casein solution is 0.2 g.(100 c.c.
All experiments hereinafter were carried on by this method.
Experimental result is as shown in Table I and this pancreas did nothave any digesting power.
Table I. Digesting Power of Fresh Pancrea! 1 g./100 c.c. pane- ,Ratio of casein-,- - - - - No.
0.2% Casein! reas extraction Water c.c. pancreas dried I Turbidity- - - __s_o_Iu_ti_on_c._c._i liquid c.c.
1_ _ _ 1matter

I

102
3

555

4:

ss/ s
I o

2
0.5!3;
4.5o±

1
2.5+++

10

57

Protein digestive power of Sperm whale Pancreatic Enzyme

In turbidity, - indicates transparent, ± slight turbidity, and turbid orprecipitation is indicated by +. This applies to all following experiments.
2. Increase of digestive power by neutral autolysis.
Minced pancreas is placed in a conical flask, a small amount of toluol
added and sealed. This is placed in a thermostatic bath, of 40°C taken out
at the time indicated in Table II and digestive power determined. Pancreas
extraction liquid is made in the same manner as before, that is, lg. ofpancreas is extracted with 100 c.c. of water and filtered.
Table II. Increase of digestive power by autolysis
Hours left i
1standing !

-No;!: O•2%0 Casein•[I'I,------,------------1--1
23

10.5hours

1234i'

I-1-!
1t--------124
hours

12

3
4
5

i

i

0
5
5i
:

-48hours

55
20
1
2.5

30
5

0

5

5

5

5± (digested)

+

0
1

5
5

1

20
3

4

2.5
5

0
5

5
5

500
1

552

2.5
5

50.5

344.5

105
00
1

3

2.5

5
5
5
55

Turbidity---.

------~~------ -----.,. --1-----------,'I
1I023456: Ratio casein i; pancreas dried !
matter·· lg./100 c.c.
I Water'Pancrea extrac·c.c.
Solution c.c. I tion liquid c.c.,

I

552l

0.5
0.2

----

_ _ _ i _____________

44.5
4.8;

5
10

2.5+ (digested)+-(digested)-(digested)++_! _ _ _ __:I++++

As can be seen from Table II, when it is allowed to autolyse at 40°C,
digestive power increase somewhat, the maximum of increase being between 10-24 hours, and its maximum value being at 2.5. That is, pancreas digest 2.5 times its weight of casein.
3. Increase of digestive p:)\ver by slightly acidic autolysis.
10 g. of minced pancreas is mixed with 2 c.c. of water and 2 c.c. of
0.1 N HCl, a small amount Of toluol added, made into several samples,
sealed and stored in a thermostatic bath of 40°C. One of these is takenout at each time indicated in Table III and digestive power determined.
The initial pH of this mixture was 5.4.
The concentration of the enzyme solution is exactly the same as in
the previous experiment and 100 c.c. of the enzyme solution is equivalent
to I g. of the original pancreas (0.2 g. as dried matter).

58

Yasutaro Ishikawa, Setsuzo Tejima

Table Ill. Increase of digestive power by autolysis (Initial pH 5.4)
Hours!~ftstanding.
I
1 g./100 c.c. I
I • c.
IP of atexpentim~
I
0.2% Casein pancreas txt- Water !Ratio ase~n !
..
No.
colution cc racted soluion c.cpancreas dned Turb1d1ty
I -HI

I ment,l!---1-11•1•I ·c~c._ _ _O___ j

1___
5_ _ _ _3 hours i~j--- ;
12I-----

1'~

i : I :

hom·I ,_. I

24 hours:·36 h~:! ;II!

matter1~·1
1i1':':(digested)t

5r -:~ - -I ~ -1-- ---+~- ---: I- ~-':~:---I

_

11

2/1

2

3
4I/

II

1
0.5

1I

3I

1:(W,=tod)± (digested)

2.5-; ; i - ;-- I ~ -!- -;_, - I~~:.~totl)

I

123
4

48 hours I 6.2-6.4

i4
4.5
___
03
4
4.5

52
I
0.5

5
II
IIII,

510I+I
2.5
510+++j+- (digested)

As can be seen from the result, it is about the same in the case ofslightly acidic as in the case of neutral, maximum increase being between
12-36 hours and its maximum value is the same, 2.5.
In order to show more readily the relation between hours left standnig
and digestive power for neutral and slightly acidic, it is as shown in theSummary Table IV.
Table IV. Hours of autolysis and digesting power.
Neutral, left standing at 40°C

Ii

pH 5.4, left standing at 40°C

Digesting power/"II- c~~in/p_a11erea~_ / Hours left standing--------~~---------------------

Hours left standing !
0
3.5
10.5
24

Digesting power___ca_!leiil(p_ancr_ea~

I·o'I

3

1

2.5
2.5

1224
36
48

2.5
2.5
2.5
1i48
- ·.. - - - - - - - -1Ii------------~

5. Increase of digestive power of cow pancreas by autolysis.
Cow pancreas was obtained directly after slaughtering from the Shibaura Slaughter House. This was frozen at -35°C, minced and used in experiment, Temperature of autolysis and other experimental conditions areexactly the same as in the case of whale.
The result is as shown in Table V. As can be seen from Table V.,

59

Protein digestive power of Sperm whale Pancreatic Enzyme

casein digested when fresh is 10 times and is 25 times casein after it isautolysed for 24 hours at 40°C.
In Table V. the standard concentration of enzyme solution was 1 g. ofminced pancreas extracted with 100 c.c. of water. When it is diluted andused, the concentration is shown in parenthesis.
Table V.
Hours !eftstandmg

Increase of digestive power of cow pancreas by autolysis. by autolysis.

Pancreas extrcasein
I N · II 0.2%
solution c.c. acted solution----------

0 hourIi

12
3
45~--1-~1 I 2
12 hours

24 hoursc.c.

Waterc.c.

Ratio casein
pancreas driedmatter52
15 (xl/10)
2 ( // )1 ( // )

03403
4

1
2.5
510
25
50

5 (xl/10)
2 ( // )1 ( // )2.5 (xl/50)
2 ( ff )1 ( // )

034
2.5
3410
2550
100
125
250

5 ( x 1/10)
2 ( II )1 ( II )2.5 ( x 1/50)
2 ( II )1 ( tl )

0
34
2.5
3
4

10
2550
100
125
250

0

-

:

5I//

I//
//

I//////////

i////

I

53I
4 . I
5 I
6I

II
1---

I
45 I
6I

15I

23//
//
//

IIIIIII.

Turbidity±//I!
//++(digested)-± (digested)+//////+// (digested)
IIIIII//-5. Protein digestion of pulverized whale and cow pancreas dried matter.
Next, the authors prepared pulverized dried pancreas of whale andcow and determined the digestive power of both. That is, minced pancreas·is left standing at room temperat~re (2-8°C) for one night, placed in alarge quantity of acetone to dehydrate, filtered with suction and washedseveral time by pouring on it. Next, it is dried by aeration, well dried ina H2SO~ desiccator, pulverized in a morter, sieved with a 60 mesh sieve,
and the digestive power of those which passed through the sieve was determined. Also, for comparison, the digestive power of both whale and cow
pancreas before dring were determined (after standing for one night).
Result of determination and the detail of yield from minced pancreas
to sieved powder is shown in Table VI and Table VII.
As can be observed from Table VI, the digestive power of whale
pancreas before drying is 0, but that of cow is 50 times. For dried pulverized whale pancreas,, it is 2.5 times, and 125 times for cow pancreas.
In ·table VI the standard for pancreas extracted solution for freshpancreas, was 1 g!lOO c.c. and 0.2 g/100 c.c. in the case of dried pulverizedYastaro Ishikawa, Setsuzo Tejima

60

pancreas, these being gradually diluted and used.
in parethesis.

Concentration is indicated

Table VI. Digestive power of dried pulverized whale and cow pancreas and before drying.
Kind

0.2%o Cas;~ ·!--Pancreas extr-- Wat~r---R~a-ti_o_c--a--s-e1~.n~-- -·---·----. acted liquid !
pancreas driedTurbidity
solution c.c. lc.c.
:, c.c..
inatterNo.

Freshwhale
pancreas :!

Driedpulverizedwhalepancreas

l234l235////flI·-·~--!

' 5 (0.2 g/100 c.c.)

5!2 (IIII

4i1 (! 5IIII

5Fresh cow
pancreas.

II4//l235(IIIIII))xl/10)! 2 ( fl x 1/10)

-----

1
2
35 (lg./100 c.c.)II)
2 (II)
l (0.5 ( II)I! 5 (1 g/100 c.c.)!2 (II):1 (II): 2.5 ( II X 1/5)

5II.

034
4.512.5510034031
2.5.
5102503102550
100

4

2.5!

Driedpulverizedcowpancreas! 2 (0. 2g.1000 c.c.)ii)
1 (. 3.5( II X 1(5)i 2.5( II x 1/5)
i2 ( II xl/5)

IIII
ff

45

II

---- - - - - - -Table VII.

Ml.need. pa·ncreas g.I
WhaleCow

99
49~-+++-+(digested)(digested)------ ------

32550
70
100
125

4

1.5
2.5
3- - -- - - - - - - - -- -++++~=(digested)-Yield on drying and sieving minced pancreas.

Acetone aried
matter g.
15.l
9.8.
d----,--;---d'd· · -Losson sieving_I Sieve
matter g. : 5 ieve res1 ue g. ;g. _____ _
9.6
r.:

S .v

.

5.3
1.1

0.2
0.2

Conclusion.
There is almost no digestive power in the fresh sp~rm whale pancreas
which was used in the experiment and by autolysis was only 2-3 times
casein. There is almost no. change in progress of increase by autolysis
m both neutral and slightly acidic condition.
In the case of cow pancreas, under the same condition, it is easy toobtain a digestive power of about 25 times by autolysis.
On standing for one night at room temp~rature, the digestive p:)\.verof whale pancreas was 0 but that of cow pancreas was 50 times. Also,
when these are dried and pulverized, digestive p::>wer of whale pancreas. was 2.5 times and 125 times in case of cow p:mcreas.
In comparing whale and cow pancreas, the amount of connective
tissues in the case of whale is very large and o!llY a small part waspulverized.