PURIFICATION BY ULTRAFILTRATION OF A FAT-MOBILIZING SUBSTANCE EXTRACTED FROM THE URINE OF FASTING RATS

Publisher Website
Google Scholar
Abstract
A substance (FMS IB) that mobilizes fat in vivo and in vitro can be extracted from the urine of fasting rats and other species. A threefold increase of lipolytic activity in vitro of rat FMS IB was accomplished by ultrafiltration of an aqueous solution through regenerated cellulose tubing (pore size 24 Å) under vacuum (10–15 mm mercury). This procedure removed a large proportion of the protein. Fat-mobilizing activity in vivo also appeared to be increased. Millipore filtration and carboxymethylcellulose treatment were without significant effect on the activity of FMS IB. Sephadex G25 fractionation of the ultrafiltrate indicated three active fractions, the first of which was not associated with protein but coincided with the presence of a small amount of carbohydrate. None of the ultrafiltrate, the residue after ultrafiltration, or a mixture of the two showed evidence of the hypoglycemic property in vivo possessed by original FMS IB. From these observations it is apparent that the fat-mobilizing activity of FMS IB can be dissociated from protein material and from the hypoglycemic property.