Was lost.
This group studied ritonuctcic acid (RNA) and desoxyribonucicic acid
Cin) dn thyzic colts of thigh ehiolded and nonshicided irradiated mice.
It was
found that the EM levels pes thynie ccli do not vary with ace or treatment
croup and that
RNA remains constant with time in the control group, but WIA inf-t>
ezcases 2 to 5 days after isradiat ca wita a prompt return to normai in the thich
shieclccd group.
Tx2 RAA per coll ond RAA/ONA catio remain markedly clevated over
the entire course of treatment in the unshielded irradiated group. These authors
Sugcest that the sustained clevation of RUA may ce related to tumor incuction,
Since shicidinsg prevents induction ond sesults in a rapid return of RNA to normal.
it is quite evicent that leutonoyencsis by ionizing radiation and the interactions between norms’ and irradiated hemopoietic tissues and endocrincs, which
are proved to infivence induction, are most intricate.
Oa the basis of the reports
to date, it is not possible to determine whether tha non-irradinted hemopoietic
tissues supply @ celiuice os humoral factor that inhibits the induction.
evidence for both views.
capable of neutralising
There is
I¢ is also conceivable that the normal tissues may be
acter Iibersted fron the irredigted tissucs,
The nature
£ the interactions between irradiated and normal tissues and the infiuence of endo=
erines on issadisted tissues remain obscure, but the existence of these physiological
interactions that influence leuicnoscenesis is umyquestioned.
The unquestioned, harmful Inte effects of ionising radistion on hematopoiesis
losicatiy leads to a discussica on the value of a study of the bleod in protecting
acainst excessive exposure to ionising radiation.
8.3
Factors Influencing the ifect of Ionising Radiation.
rotective facters are discussed in detail im Chapter 10, section
shoush preprotective agents may protect all celiutas systexs into which the
semicnl substances con penetrate, tho most striking effects are seen in the blood-