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INFLUENCE OF SOLAR RADIATION ON IMMUNITY, II [Vol. XXI, Part III,
directing influence of the antigen. This influence is exerted through a union,
physical or chemical, between the peptides or amino acids and the active groupings
of the antigen during the globulin synthesis. Ehrich and Harris [1942] pointed
out that the reticulo-endothelial theory of antibody formation is not supported by
evidence in its entirety. Evidence is available that the lymphocytes have some-
thing to do with the gamma globulins and antibodies in that they either store or
produce globulins. Harris et al. [1945] demonstrated that the lymph node anti-
bodies are contained largely in the lymphocytes during antibody formation. The
lymphocyte functions as a vehicle for the antibody. Chase et al. [1946] observed
that antibodies of the blood are generally present in the beta or gamma globulin
fractions of the serum proteins. Gamma globulin is a normal constituent of lympho-
cytes. The release of gamma globulin from lymphocytes as a consequence of aug-
mented pituitary-adrenal cortical secretion suggested that the adrenal cortical
steroids might influence antibody levels in the serum. This hypothesis received
support from the fact that lymphoid tissue has long been considered a site of anti-
body production. The rate of release of the globulin from lymphocytes is, there-
fore, directly connected with the amount of pituitary and adrenal secretions.
Explaining the phenomenon of 'lymphocytic dissolution', the same workers observ-
ed that this release is produced by the removal of cytoplasm from the lymphocytes
and is accentuated by increased amounts of adrenal cortical hormone. The con-
stituents of lymphocyte cytoplasm are thereby released to the lymph and reach the
circulation. Thus, by this mechanism, adrenal cortical stimulation results in an
elevated gamma globulin level in normal serum and an increased antibody con-
centration in the immunized animal. Cannon [1944] remarked 'Evidence appears
conclusive that an antibody is a globulin which has been specifically modified by
an antigen'.
The effects of environmental temperature and humidity on the power of re-
sistance of the body against infectious diseases have already been dealt with in the
Introductory Chapter in Part I. In the series of experiments conducted by the
author the experimental groups were daily exposed to the direct rays of the sun
for a period of 8 to 10 days after vaccination. The influence of solar radiation on
the antibody—forming mechanism is discussed in the following lines. As all the
animals exposed to the sun also received variable amounts of ultra-violet irradia-
tion, it is necessary at this stage to discuss the effect of the latter on the resistance
to infection. Previously, the ultra-violet irradiation of the body surface was
advocated as a means of increasing resistance to infection, but now-a-days the
balance of evidence appears to be very definitely against the view that exposure to
such rays has any significant effect. Chapman and Hardy [1931] were unable to
obtain any evidence that irradiation increases the resistance of rabbits to the sub-
cutaneous injection of Pasteurella lepiseptica. Hill, Greenwood and Topley [1930]
found that irradiation conferred no benefit on mice submitted to contact infection
with Pasteurella muriseptica. There is practically no literature dealing with the
problem, e.g., effects of solar radiation on the formation of antibodies. The subject
rob very complex one and it is evident that a number of factors, both intrinsic and
extrinsic, are collectively concerned in this act. When the animal is exposed to
the sun, a series of actions and reactions, physical, chemical and physiological, take
place in the animal body and the cumulative actions of these series of changes are