IV.
ACTION OF MORPHOSTATIC SUBSTANCES
177
conceivable that the well known loss of weight in animals bearing large
tumours is caused by the peculiar functioning of the mobilization
mechanism of proteins of the host. However the question remains
open at present as to whether the parasitic tumour is only a simple
trap for vital proteins or whether the tumour is producing in addition
some specific effector substances which activate further the mobilizing
mechanisms of the host. At present we see clearly a relation between
starvation and protein deficiency on one side and the reduction of
organs and the activation of proteases on the other side in tumourbearing animals.
3. The Catheptic Activity of Growing and Regressing Tumours of Rodents
Behaviour of growing tumours. If our considerations were correct, the
cells of growing tumours ought not to show an essentially higher
catheptic activity than normal tissues, whereas in regressing tumours
the cells should develop an increased catheptic activity. The preliminary
results of Benz (1959) support our assumption. Some tumours of the rat
seem to possess several layers. The peripheral layer contains numerous
cells which are actively proliferating (Α-cells). The neighbouring layer
contains many B-cells which are less active and are rich in cytoplasm.
Sylvén and Malmgren (1957) have determined the catheptic activity on
frozen sections. They conclude from their results that the Α-cells contain a higher catheptic activity than the B-cells.
Benz (1959) has isolated by mechanical means different zones from
larger tumours. He distinguishes a necrotic central mass, a vital
peripheral layer and host tissues forming the 'contact region' to the
tumour. These different regions possess different catheptic activity.
The peripheral tumour layer shows a catheptic activity which has about
the same level as that of liver. The increased catheptic activity of the
tissues from the contact zone is very striking (Fig. 13). These preliminary
findings have yet to be confirmed by detailed investigations. Surprisingly
enough the necrotic tumour centre is very low in its catheptic activity.
Probably cell necrosis and catheptic activity are not directly coupled.
The increased catheptic activity of the peripheral tumour region is
also demonstrated by the 'cathepsin autogrammes' of Benz (1959).
Cathepsin-autography is possible because of the differential distribution
of cathepsins in fresh tissue slices. The regions of a tissue slice which are
very rich in cathepsins dissolve, at a pH of 5, the gelatine of a homogeneously blackened photographic film and thus produce a beautiful
map of the differential enzyme distribution of a given tissue slice. This
method also demonstrates a high catheptic activity in the peripheral
tumour layer and a very low catheptic activity in the central necrotic
part (Fig. 13).
ACTION OF MORPHOSTATIC SUBSTANCES
177
conceivable that the well known loss of weight in animals bearing large
tumours is caused by the peculiar functioning of the mobilization
mechanism of proteins of the host. However the question remains
open at present as to whether the parasitic tumour is only a simple
trap for vital proteins or whether the tumour is producing in addition
some specific effector substances which activate further the mobilizing
mechanisms of the host. At present we see clearly a relation between
starvation and protein deficiency on one side and the reduction of
organs and the activation of proteases on the other side in tumourbearing animals.
3. The Catheptic Activity of Growing and Regressing Tumours of Rodents
Behaviour of growing tumours. If our considerations were correct, the
cells of growing tumours ought not to show an essentially higher
catheptic activity than normal tissues, whereas in regressing tumours
the cells should develop an increased catheptic activity. The preliminary
results of Benz (1959) support our assumption. Some tumours of the rat
seem to possess several layers. The peripheral layer contains numerous
cells which are actively proliferating (Α-cells). The neighbouring layer
contains many B-cells which are less active and are rich in cytoplasm.
Sylvén and Malmgren (1957) have determined the catheptic activity on
frozen sections. They conclude from their results that the Α-cells contain a higher catheptic activity than the B-cells.
Benz (1959) has isolated by mechanical means different zones from
larger tumours. He distinguishes a necrotic central mass, a vital
peripheral layer and host tissues forming the 'contact region' to the
tumour. These different regions possess different catheptic activity.
The peripheral tumour layer shows a catheptic activity which has about
the same level as that of liver. The increased catheptic activity of the
tissues from the contact zone is very striking (Fig. 13). These preliminary
findings have yet to be confirmed by detailed investigations. Surprisingly
enough the necrotic tumour centre is very low in its catheptic activity.
Probably cell necrosis and catheptic activity are not directly coupled.
The increased catheptic activity of the peripheral tumour region is
also demonstrated by the 'cathepsin autogrammes' of Benz (1959).
Cathepsin-autography is possible because of the differential distribution
of cathepsins in fresh tissue slices. The regions of a tissue slice which are
very rich in cathepsins dissolve, at a pH of 5, the gelatine of a homogeneously blackened photographic film and thus produce a beautiful
map of the differential enzyme distribution of a given tissue slice. This
method also demonstrates a high catheptic activity in the peripheral
tumour layer and a very low catheptic activity in the central necrotic
part (Fig. 13).