152
s.-A. KILLMANN AND OTHERS
BAIBA,but evidence for a similar pathway in man is lacking.
In man,
BAIBAappearsto be a'specific catabolite of thymine-containing compounds.
Following substantial exposure .to ionizing radiation with ensuing cell
destruction and inhibition of DNA-synthesis one might expect an increased
excretion of BAIBA in the urine. A study of this question was undertaken
by Rubiniet al. (1959) in the 8 operators who were exposedin thecriticality
accident at Oak Ridge in June 1958 (Fig. 1).
Urine specimens were
FIG. 1
URINARY EXCRETION OF BAIBA IN VICTIMS OF THE Y-12 ACCIDENT,
OAK RIDGE, JUNE 1958
650
]
600 F—
550;F500 ;-—
|
+
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oOo
wm
Qo
tal
Oo
o
Ww
NH
wn
2
T
Ny
Oo
oO
Excretion of BAIBA (uMilitre
450/-
150
50/-
Days after exposure
Upper normal limi of BAIBA excretion with method used = 150 uM/litre
a)
“d
Reproduced, by permission, from Rubini et al. (1959)
received from the 3rd to 8th day after exposure.
In 3 patients who received
less than 100 rad no excess urinary excretion of BAIBA was detectable.
The remaining 5 patients with higher exposures (236-365 rad) excreted
BAIBAin amounts larger than normal, with a maximum duringthefirst two
days on which specimens were available, that is day 3 and day 4. The
excretion of BAIBA was roughly dependentonthe dose.
In this study, the output of BAIBA was estimated by means of twodimensional paper chromatography. Subsequent studies of the same urine