260 



ADVENTURES IN RADIOISOTOPE RESEARCH 



EXPERIMENTS ON CHICKS 



Labelled phosphate was administered hy subcutaneous injection to chicks 

 (Aj, Ag and A3, respectively). After the lapse of a day, plasma samples of these 

 chicks were taken. One part (1 cc.) of the sample was injected into the jugularis of 

 the chicks B^, C^, D^, E^, B^, C^, Dg a^^d B3, C3, Dg, Eg, Fg, respectively; another 

 part was analysed. After the lapse of 7 to 67 minutes, plasma samples of chicks 

 B, C, D, E and F, respectively-, were taken and the activity of their phosphatide 

 content determined; heparin was added to the blood before it was centrifuged. 

 In Tables 3, 4 and 5, the results of these experiments are recorded. The time recor- 

 ded in Tables 3 and 5 was reckoned from the middle of the time of injection, 

 which took about one minute. 



Table 3. — Pkrcentage of Labelled Phosphatides Present in the Plasma of 

 Chicks Bj, C^, D^, after Injection of 1 cc. Plasma of Chick A^ Containing 



Labelled Phosphatides 



As seen in Table 3, after the lapse of 17.0 to 17.9 min, 1 cc. of the plasma of 

 chicks Bj,, Cg and Dg, respectively, contains only about 7 per cent of the labelled 

 phosphatide present in 1 cc. of the plasma of chick A injected into chicks Bg, C<, 

 and Dg, respectively. This decrease is partly due to a dilution of the labelled phos- 

 phatides present in 1 cc. by the non-labelled phosphatides present in about 4 cc. 

 plasma of chicks Bg, C.2 and D^, and partly to an escape of the labelled phosphatides 

 through the capillary wall into the organs and its replacement by non-labelled 

 ones previously present in the organs. As seen in the last column of Table 3, from 

 100 labelled phosphatide molecules introduced into the circulation of the chicks, 

 only about 37 were present in the plasma after the lapse of about 17 min. 



Since the labelled phosphatides cannot be expected to show a different behaviour 

 fiom the non-labelled ones, we can conclude that 63 per cent of all individual 

 phosphatide molecules originally present are no longer in the plasma of the chick 

 after the lapse of 17 min., being replaced by phosphatide molecules originally 

 located outside the capillary wall. 



In the first experiment which we carried out on chicks (see Table 4), we ha\-e 

 chosen another procedure. We compared the activity of 1 mgm phosphatide P 

 extracted from 1 cc. plasma of chick A with the activity of 1 mgm phosphatide P 

 extracted from 1 cc. plasma of chick B, C, D and E, respectively. Should the 

 phosphatide concentration in the plasma of the different chicks used in this expe- 

 liment be about the same, we could calculate from the data obtained the loss 

 of labelled phosphatides through the capillary wall in the course of the first 7 

 and the consecvitive 60 min. as well. When determining the phosphatide content 

 of the plasma in our second experiment, we found, howcA-er, very pronounced 

 differences between the plasma phosphatide contents of the chicks used. (Chick 



