1002 



ADVENTURES IN RADIOISOTOPE RESEARCH 



In the normal 100 gm rat 15 mgm glucose were found to build up per 

 hour, in the diabetic rat 21 mgm. The formation of glucose from sources 

 not derived from the infused glucose was found to be enhanced up to 

 7 -fold after administration of cortisone. 



Clinical investigations on glucose turnover applying i^C labelled glu- 

 cose were carried out as well^'^^ From the change of the specific activity 

 of the exhaled COg and of the plasma glucose with time it was calculated 

 that 31 per cent of the CO2 expired derived from oxydation of glucose 

 in normals. In diabetics not showing ketosis this percentage was some- 

 what depressed to 27 but in those showing ketosis, to the markedly depres- 

 sed value of 19. A normal human subject weighing 70 kgm was found to 



80- 



40- 



Leber BrenztraubensQure ^glukose 



___tL \^-- 



Leber giukose — 6 — Phosphatase 



o 

 9- 



6- 



3- 



^k 



I U^^^^ 



I 



— I 1 — 



6 ■ ■ 12 24- 

 Stund en 



— r 

 48 



Fig. 2. — Effect of administration of insulin to the rat on the rate of 

 conversion of pyruvate-"C into labelled glucose and on the level 

 of glucose- phosphate activity measured as milligram of phosphorus 

 released from glucose-6phosphate per gram of liver per 30 minutes. 



burn 3.8 gm glucose per hour, some of the "stable" diabetes patients 

 almost the same, the labile ones 2.2 gm only. 



In these experiments 90 fiC of glucose extracted from tobacco plants 

 which were grown in a ^^COg containing atmosphere were injected into 

 the circulation. All carbon atoms of such glucose are labelled. Such an 

 amount of i*C exposes the organism to a radiation close of 0.17 Mrep 

 in the course of the first hour, the dose soon decreasing due to excretion 

 of "C. 



