184
F.
Ε.
LEHMANN
activity increases and it is suggested, by the histological picture and by
cathepsin autographs, that a regressing tumour is degraded by its own
cathepsins. If a combination of morphostatic substances forces a living
tumour to regress, it may be presumed that in this case the tumour
starts out to degrade its own proteins by its own activated cathepsins.
This method of tumour regression which seems now empirically possible
has to be substantiated by experiments on tumour-bearing animals.
Here remains another large field for our research group.
D. Enzymatic Actions of Morphostatic Substances
and Structural Effects of Antimitotic Substances
Our experimental results disclosed the fact that morphostatic
substances like the quinoxaline 3576 and the aminoketone 9 are strong
inhibitors of regeneration but they do not have any considerable
influence on mitosis. These substances cannot be called 'antimitotic'
substances. The morphostatic effect of a substance does not necessarily
involve an antimitotic effect. There are however several substances
known which can act either as antimitotic or morphostatic substances.
Colchicine and the iminoquinones belong to this group of compounds.
Which morphogenetic and biochemical substrate is modified is the
problem in such a case. In Xenopus a biological substrate has to be
assumed, the activities of which can be modified or suppressed either by
morphostatic or by antimitotic substances. This substrate must be the
seat of different enzyme and molecular systems which carry, if fully
integrated, a very high morphogenetic potential with a strong capacity
for growth, regeneration and mitosis. The limiting factor of this system
is probably the turnover of proteins which are of importance in biochemical and structural respects. Cells rich in basophilic cytoplasm are
important in regeneration, and the mitotic apparatus also requires for
its architecture a considerable amount of fibrillar basophilic cytoplasm.
Seen from the biochemical viewpoint the hyaloplasm of regenerate cells,
or cells ready to divide, is a system very rich in enzymes but not carrying
too many oxidative enzymes. It is a system with protein fibrils with
adjacent chromidia which contain many nucleic acids and phosphatides
and with numerous microsomes rich in nucleic acids. The hyaloplasm is
imbibed with an interstitial fluid in which are dissolved phosphates rich
in energy and low molecular peptides. We can found our hypothesis on
many facts. This system of the hyaloplasm seems to be very changeable
as far as sol and gel structure and as far the metabolism of proteins is
concerned. The system of hyaloplasm is very well developed in all cells
which take part in morphogenetic and mitotic processes. Correspondingly a high level of activity of the enzyme systems involved is to be
F.
Ε.
LEHMANN
activity increases and it is suggested, by the histological picture and by
cathepsin autographs, that a regressing tumour is degraded by its own
cathepsins. If a combination of morphostatic substances forces a living
tumour to regress, it may be presumed that in this case the tumour
starts out to degrade its own proteins by its own activated cathepsins.
This method of tumour regression which seems now empirically possible
has to be substantiated by experiments on tumour-bearing animals.
Here remains another large field for our research group.
D. Enzymatic Actions of Morphostatic Substances
and Structural Effects of Antimitotic Substances
Our experimental results disclosed the fact that morphostatic
substances like the quinoxaline 3576 and the aminoketone 9 are strong
inhibitors of regeneration but they do not have any considerable
influence on mitosis. These substances cannot be called 'antimitotic'
substances. The morphostatic effect of a substance does not necessarily
involve an antimitotic effect. There are however several substances
known which can act either as antimitotic or morphostatic substances.
Colchicine and the iminoquinones belong to this group of compounds.
Which morphogenetic and biochemical substrate is modified is the
problem in such a case. In Xenopus a biological substrate has to be
assumed, the activities of which can be modified or suppressed either by
morphostatic or by antimitotic substances. This substrate must be the
seat of different enzyme and molecular systems which carry, if fully
integrated, a very high morphogenetic potential with a strong capacity
for growth, regeneration and mitosis. The limiting factor of this system
is probably the turnover of proteins which are of importance in biochemical and structural respects. Cells rich in basophilic cytoplasm are
important in regeneration, and the mitotic apparatus also requires for
its architecture a considerable amount of fibrillar basophilic cytoplasm.
Seen from the biochemical viewpoint the hyaloplasm of regenerate cells,
or cells ready to divide, is a system very rich in enzymes but not carrying
too many oxidative enzymes. It is a system with protein fibrils with
adjacent chromidia which contain many nucleic acids and phosphatides
and with numerous microsomes rich in nucleic acids. The hyaloplasm is
imbibed with an interstitial fluid in which are dissolved phosphates rich
in energy and low molecular peptides. We can found our hypothesis on
many facts. This system of the hyaloplasm seems to be very changeable
as far as sol and gel structure and as far the metabolism of proteins is
concerned. The system of hyaloplasm is very well developed in all cells
which take part in morphogenetic and mitotic processes. Correspondingly a high level of activity of the enzyme systems involved is to be