CHAPTER
IV
ACTION OF MORPHOSTATIC
SUBSTANCES AND
THE ROLE OF PROTEASES IN REGENERATING
TISSUES
AND IN TUMOUR CELLS
F.
E.
LEHMANN
I. Specific Modification of the Growth of Regenerates and Tumours by Chemical
Factors
153
II. Combined Action of Several Inhibitory Substances and the Total Suppression
of Growth
154
A.
Selective Suppression of Regenerative Growth by Pairs of Morphostatic
Substances
155
B.
Inhibition of an Adenocarcinoma of the Mouse by a Pair of Morphostatic
Substances
162
III. Proteases of Growing Tissues and the Regulation of Growth Processes
166
A.
Morphostatic Substances as Inhibitors of Regenerative Growth and as
Activators of Tissue Proteases (Cathepsins)
167
B.
Cathepsins as Regulators of Growth in Normal and Tumour-bearing Rats
173
IV. Aspects of Chemically-induced Growth Inhibition
179
A.
Growth as a Synergistic Process
179
B.
Growth as a Process Integrated in Space and in Time
180
C.
Growth as a Phenomenon of Biochemical Integration
181
D.
Enzymatic Actions of Morphostatic Substances and Structural Effects of
Antimitotic Substances
184
References
186
I. Specific Modification of the Growth of
Regenerates and Tumours by Chemical Factors
It is the aim of modern developmental and tumour biology to modify
growth processes by specific chemical factors. Tardent (1956) has
suppressed the regeneration of hydranths of Tubularia by immersing
amputated stumps from which the hydranth had been previously
amputated, in extracts prepared from homogenates of differentiated
hydranths. This 'self-inhibiting' action of substances contained in the
adult hydranth seems to be carried by substances which are active only
during the first stages of regeneration. Selective inhibition of growth is
also possible in tumour biology. Certain cytoclastic substances (Domagk,
1956; Oettel and Wilhelm, 1957; Druckrey et al., 1958) suppress some
tumours selectively without exerting any lethal effects upon the tumourbearing hosts.
153