An interpretation of the results of measurements of the uptake of³²P in human tumours

Circadian variations in 32P uptake of a DMBA-induced mammary tumour and Walker carcinosarcoma in rats

“…32p measurements.-At least 3 days before the start of the measurements, the rats were injected with 32p orthophosphate, 0-02 uCi/g i.p. in order to permit an equilibrium of 32p to be established in the animal (Taylor et al, 1968). During the 32p uptake measurements the count rates were not less than 1000 ct/h, which gave a relative uncertainty of the accumulated counts <3%.…”

“…The decrease in activity during the light period would furthermore require an extensive cell death which has never been recognized in this tumour. In a study of human tumours, Taylor et al (1968) found a better explanation of the daily variations, as 32p uptake corresponded to fluctuations in the RNA content of the tumour tissue. The results would be influenced by changes in the radioactivity in the blood, but this has not been found in previous studies (Taylor et at., 1968;Woolley-Hart et at., 1968).…”

“…In a study of human tumours, Taylor et al (1968) found a better explanation of the daily variations, as 32p uptake corresponded to fluctuations in the RNA content of the tumour tissue. The results would be influenced by changes in the radioactivity in the blood, but this has not been found in previous studies (Taylor et at., 1968;Woolley-Hart et at., 1968). Furthermore, as the circadian variations were found only in the DMBA-induced tumour and not in skin or Walker carcinosarcoma, the variations in 32p uptake could not be directly related to changes in the specific activity of blood.…”

“…In human breast cancer it has been difficult to find a periodicity in the uptake of 32p (Bullen et al, 1963;Calcutt et al, 1967;Taylor et al, 1968) partly due to technical difficulties, but Stoll and Burch (1968) found a circadian rhythm in the late 32p uptake in 9 out of 19 patients with mammary carcinoma. The temperature variations in the adjacent skin followed the 32p curve, both curves having low diurnal and high nocturnal levels.…”

“…SOME years ago there was a great interest for the circadian variations in 32p uptake in human breast cancer (Bullen et al, 1963;Calcutt et at., 1967;Stoll and Burch, 1968;Taylor et al, 1968;Woolley-Hart et al, 1968). In this connection the word " uptake " is taken to mean the changes in measured radioactivity from 32p in the tissue once equilibrium is established.…”