title: Simplified enzymatic synthesis and biodistribution of 11C-S-adenosyl-L-methionine.
abstract: 11C-S-Adenosyl-L-methionine (11C-SAM) was synthesized enzymatically from 11C-L-methionine using rat-liver extract [40%-50% saturated (NH4)2SO4 fraction] as the enzyme source. In biodistribution studies in rats, the highest uptake of 11C-SAM was found in the kidneys. 11C-SAM was also accumulated in the small intestine, pancreas, adrenal gland, liver, and spleen. The uptake of 11C-SAM in the brain increased with time, but remained low. At 30 min after injection, about 50%-60% of the 11C radioactivity was present in the acid-insoluble fraction of the kidneys and liver. When a high loading dose of 11C-SAM was administered, the kidney uptake was enhanced, but the proportion of the radioactivity present in the acid-insoluble fraction was lower. In a study of one rabbit, the kidney uptake was of 11-SAM clearly visualized using positron-emission tomography.
mesh_terms: D000818:Animals; D002250:Carbon Radioisotopes; D007668:Kidney / Q000000981:diagnostic imaging*; D008297:Male; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains; D012436:S-Adenosylmethionine / Q000138:chemical synthesis / Q000378:metabolism; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed
chemical_list: D002250:Carbon Radioisotopes; D012436:S-Adenosylmethionine