THE STIMULUS TO HYPERTROPHIC GROWTH
119
plasmic?) growth process is higher in the weanling livers (this would have
the effect of subtracting a constant from the ordinate of the response curve).
The important thing is not what additional assumptions must be made to
reconcile the empirical curve with our theoretical function, but that the
theory of humoral feedback inhibition predicts the observed pattern of
response to the experimental reduction of tissue mass.
D. Summary
The problem of the mechanism of specific growth control responsible
for the stimulus to hypertrophic growth in liver, kidney, and possibly in
other tissues is still unsolved. Control seems to be exerted on the rate of
cytoplasmic synthesis, rather than on the rate of cell division. There is no
reason to suppose that mechanisms of growth control in different tissues
are essentially different.
The only explicit theory which has been advanced to account for all the
experimental results reported is Weiss's theory of feedback inhibition of
organ growth. However at the present time there is very little firm supporting evidence. The very rapid turnover which must be a property of the
hypothetical inhibitors will make their unequivocal demonstration a very
difficult task.
Acknowledgment
The author wishes to express his appreciation for the benefits of discussions with
Dr. Paul Weiss and other members of his laboratory, and Dr. Christian de Duve.
References
Abercrombie, M. (1957). Localized formation of new tissue in an adult mammal
Symp. Soc. Exp. Biol. 11, 235.
Adibi, S., Paschkis, Κ. E., and Cantarow, A. (1959). Stimulation of liver mitosis by
blood serum from hepatectomized rats. Exptl. Cell Res. 18, 396.
Akamatsu, N. (1923). Über Gewebskulturen von Lebergewebe. Arch. Pathol. Anat.
Physiol. 240, 308.
Alho, A. (1961). Regeneration capacity of the submandibular gland in rat and mouse.
Acta Pathol. Microbiol. Scand. Suppl. 149, 1.
Allen, R. B., and Mann, F. C. (1935). Experiments on compensatory renal hypertrophy. ΑΜΑ Arch. Pathol. 19, 341.
Alston, W. C, and Thompson, R. Y. (1963). Humoral and local factors in liver
regeneration. Cancer Res. 23, 901.
Anderson, H. (1926). Experimental renal insufficiency: the effects of high protein
diet in the presence of low renal function on the kidneys, aorta, and liver;
changes in the blood pressure and concentration of blood metabolites. II. Protein diet experiments. ΑΜΑ Arch. Internal Med. 37, 313.
Andres, G. (1955). Growth reactions of mesonephros and liver to intravascular injections of embryonic liver and kidney suspensions in the chick embryo. J.
Exptl. Zool. 130, 221.
119
plasmic?) growth process is higher in the weanling livers (this would have
the effect of subtracting a constant from the ordinate of the response curve).
The important thing is not what additional assumptions must be made to
reconcile the empirical curve with our theoretical function, but that the
theory of humoral feedback inhibition predicts the observed pattern of
response to the experimental reduction of tissue mass.
D. Summary
The problem of the mechanism of specific growth control responsible
for the stimulus to hypertrophic growth in liver, kidney, and possibly in
other tissues is still unsolved. Control seems to be exerted on the rate of
cytoplasmic synthesis, rather than on the rate of cell division. There is no
reason to suppose that mechanisms of growth control in different tissues
are essentially different.
The only explicit theory which has been advanced to account for all the
experimental results reported is Weiss's theory of feedback inhibition of
organ growth. However at the present time there is very little firm supporting evidence. The very rapid turnover which must be a property of the
hypothetical inhibitors will make their unequivocal demonstration a very
difficult task.
Acknowledgment
The author wishes to express his appreciation for the benefits of discussions with
Dr. Paul Weiss and other members of his laboratory, and Dr. Christian de Duve.
References
Abercrombie, M. (1957). Localized formation of new tissue in an adult mammal
Symp. Soc. Exp. Biol. 11, 235.
Adibi, S., Paschkis, Κ. E., and Cantarow, A. (1959). Stimulation of liver mitosis by
blood serum from hepatectomized rats. Exptl. Cell Res. 18, 396.
Akamatsu, N. (1923). Über Gewebskulturen von Lebergewebe. Arch. Pathol. Anat.
Physiol. 240, 308.
Alho, A. (1961). Regeneration capacity of the submandibular gland in rat and mouse.
Acta Pathol. Microbiol. Scand. Suppl. 149, 1.
Allen, R. B., and Mann, F. C. (1935). Experiments on compensatory renal hypertrophy. ΑΜΑ Arch. Pathol. 19, 341.
Alston, W. C, and Thompson, R. Y. (1963). Humoral and local factors in liver
regeneration. Cancer Res. 23, 901.
Anderson, H. (1926). Experimental renal insufficiency: the effects of high protein
diet in the presence of low renal function on the kidneys, aorta, and liver;
changes in the blood pressure and concentration of blood metabolites. II. Protein diet experiments. ΑΜΑ Arch. Internal Med. 37, 313.
Andres, G. (1955). Growth reactions of mesonephros and liver to intravascular injections of embryonic liver and kidney suspensions in the chick embryo. J.
Exptl. Zool. 130, 221.