680
H O N O R B. FELL A N D L . M. R I N A L D I N I
In general, the results reviewed above suggest that one site of action
ofthe vitamin is the lipoprotein membranes ofthe cell, and it is possible
that under normal conditions one function of vitamin A is to regulate
the permeability of these membrane systems. As yet, however, we know
nothing about the biochemical action of the vitamin on the synthetic
processes of the cells in the tissues studied in culture, and further
investigation of explants may show that the lipoprotein membranes
are not the only cellular mechanism to be affected by the vitamin.
I I . V I T A M I N C
A. I N T R O D U C T I O N
Among the vast amount of work published on vitamin C comparatively little has been done with Tissue-Culture methods. Most papers
in this field deal with the effect of ascorbic acid on growth or on the
synthesis of intercellular materials, and some of them are open to
criticism merely on technical grounds, such as, for instance, assaying
the vitamin in complex biological media which contain an unmeasured
amount of it, judging its effect by inadequate criteria of response, or
ignoring the high instability of the vitamin, or the influence upon it of
other components of the medium. Consequently, the contribution of
Tissue Culture to research on ascorbic acid has been thus far rather
scanty. Yet there is ample scope for studies on the role of ascorbic
acid in living cells in vitro which may bridge the gap in our knowledge
between studies in the whole organism and findings in tissue homogenates or subcellular fractions.
Ascorbic acid (ASA), the reduced form of vitamin C, is almost
universally present in animal and plant cells. Tissue levels and requirements in animals are much higher than those of other vitamins (in
animal material: Bessey and King, 1933; Yakorsky Almaden and King,
1934; Glick and Biskind, 1936; King, 1936, 1939; Giroud, 1939;
Butler and Cushman, 1940, 1941; Roe and Kuether, 1943; Reid, 1954;
Rinaldini, 1960; Martin, 1961; in plants: Birch and Harris, 1933;
Birch, Harris and Ray, 1933; Bessey and King, 1933; Harris and
Olliver, 1942; Chayen, 1953; Mapson, 1954; Olliver, 1954).
Various physiological roles have been assigned to vitamin C and
some of the biochemical reactions in which it takes part have been
definitely traced in vitro and in vivo, but a unified concept about its mode
of action has not yet been established. Indeed, it looks at present as
though the vitamin may function in more than one way.
ASA is synthesized by plants and by most animal species studied so
far, except the primates, the guinea-pig, a fruit-eating bat and a
H O N O R B. FELL A N D L . M. R I N A L D I N I
In general, the results reviewed above suggest that one site of action
ofthe vitamin is the lipoprotein membranes ofthe cell, and it is possible
that under normal conditions one function of vitamin A is to regulate
the permeability of these membrane systems. As yet, however, we know
nothing about the biochemical action of the vitamin on the synthetic
processes of the cells in the tissues studied in culture, and further
investigation of explants may show that the lipoprotein membranes
are not the only cellular mechanism to be affected by the vitamin.
I I . V I T A M I N C
A. I N T R O D U C T I O N
Among the vast amount of work published on vitamin C comparatively little has been done with Tissue-Culture methods. Most papers
in this field deal with the effect of ascorbic acid on growth or on the
synthesis of intercellular materials, and some of them are open to
criticism merely on technical grounds, such as, for instance, assaying
the vitamin in complex biological media which contain an unmeasured
amount of it, judging its effect by inadequate criteria of response, or
ignoring the high instability of the vitamin, or the influence upon it of
other components of the medium. Consequently, the contribution of
Tissue Culture to research on ascorbic acid has been thus far rather
scanty. Yet there is ample scope for studies on the role of ascorbic
acid in living cells in vitro which may bridge the gap in our knowledge
between studies in the whole organism and findings in tissue homogenates or subcellular fractions.
Ascorbic acid (ASA), the reduced form of vitamin C, is almost
universally present in animal and plant cells. Tissue levels and requirements in animals are much higher than those of other vitamins (in
animal material: Bessey and King, 1933; Yakorsky Almaden and King,
1934; Glick and Biskind, 1936; King, 1936, 1939; Giroud, 1939;
Butler and Cushman, 1940, 1941; Roe and Kuether, 1943; Reid, 1954;
Rinaldini, 1960; Martin, 1961; in plants: Birch and Harris, 1933;
Birch, Harris and Ray, 1933; Bessey and King, 1933; Harris and
Olliver, 1942; Chayen, 1953; Mapson, 1954; Olliver, 1954).
Various physiological roles have been assigned to vitamin C and
some of the biochemical reactions in which it takes part have been
definitely traced in vitro and in vivo, but a unified concept about its mode
of action has not yet been established. Indeed, it looks at present as
though the vitamin may function in more than one way.
ASA is synthesized by plants and by most animal species studied so
far, except the primates, the guinea-pig, a fruit-eating bat and a