A radioenzymatic assay for plasma adenosine

✍ Scribed by Deborah Campano German; Nicholas M. Kredich

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 479 KB
• Volume: 142
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(84)90503-7

✦ Synopsis

A method for analysis of plasma adenosine which combines the principles of radioisotope dilution and enzymatic catalysis is presented. Plasma from venous heparinized blood containing the adenosine deaminase inhibitor 2'deoxycoformycin is mixed with a small amount of [3H]adenosine and extracted with perchlotic acid. Using highly purified enzyme and [Y-'~P]GTP as the phosphate donor, the neutmlized extract then serves as substrate for adenosine kinase, and the AMP product is puritied by high-performance liquid chromatography. Adenosine concentrations in plasma are linearly proportional to 32P/3H ratios in the enzymatically synthesized AMP and are calculated from a standard curve. The advantages of the method are: ease of sample preparation; sensitivity of 20 nM in as little as 0.3 ml plasma; 20 samples per day can be analyzed by a single operator. Care must be used when obtaining plasma since cellular contamination will atfect results. Using this assay, human plasma adenosine levels are 0.121 f 0.054 pM for males and 0.101 f 0.067 FM for females. 0 1984 Academic POW inc.